There are many web sites giving maintenance tips (see Links & References) and a couple of manuals / books of use too. This page will try and capture any peculiar tips for the 318is which may not be clear or specific enough elsewhere.
Servicing intervals are dictated by the SI board depending on the number of cold starts, driving style (throttle opening and time above 4000 rpm) but average 4000-8000 miles. Inspections I and II are carried out alternatively.
Inspection I & 2 tables (link to the E30 Network site)
See the Faults page for discussions on the common problems known as
those specific maintenance procedures are covered there.
Control Arm / Bushing
I have an article on upgrading to the M3 bushing, but it covers the maintenance tasks too. Click here to get to it.
Bleeding the coolant system
Time = 10 minutes
The engine and radiator are well designed to pretty much self bleed
so this is not too difficult.
- Remove the radiator cap.
- Pour in a water/antifreeze solution (as required in your area) so that it reaches the level mark on the radiator.
- Turn the interior heater/air con to full heat and turn the fan to its 1st position.
- Start the engine.
- Continue to slowly add coolant until it is ~2"/50mm above the level mark on the radiator. Keep the level there while the engine idles.
- After about 5 minutes the top radiator hose should be getting hot as the thermostat opens. Once this is warm, loosen the bleed screw slightly until some air or coolant comes slowly out (~3-4 turns).
- Bring the revs up a little and watch the bleed screw. As soon as pure coolant with no bubbles is coming out, tighten the screw with the revs still raised.
- Check the coolant level and replace the radiator cap.
- With fresh water, wash down the area around the front and side of the radiator to remove any antifreeze which may have come in contact with the paintwork.
- After ~1-2 hours of use, release the bleed screw again, bring up the revs, check for bubbles coming out and check the coolant level again.
Time = 1 hour 30 minutes Task=Fairly Easy
- Consider changing the thermostat at the same time (see below)!
- Consider flushing the coolant system if it has not been done in the previous 2 years.
- Open the radiator drain plug and remove 4-5 litres of coolant.
- Remove the two spring clips and lift up the fan shroud
- Remove the thermo-fan (left-hand/reversed thread) by clamping it with a vice grips and giving it a sharp blow clockwise.
- Loosen the four 10mm water pump pulley bolts - then remove the fan belt by slackening the alternator adjustment (13mm & 17mm spanners). Remove the pulley.
- The water pump needs to be removed by evenly screwing two of its own bolts into the threaded holes at 12 and 6 o'clock to push out the pump. There are 3 10mm bolts and one 6mm allen keyed bolt. See pic showing the holes where the bolts were removed (2 on top, 2 below) and where they were reinserted.
- Install the new o-ring on the pump (unless already fitted).
- Check the housing is clean and hand locate the pump. There is no gasket.
- Partially insert the 6mm allen headed bolt to locate the pump. Using a drift, gently tap the pump inwards - only hit the outer perimeter.
- Now install the remaining bolts. Tighten them evenly and use them to pull the pump in the full way. The pump usually pops into position.
- No not over torque the bolts (7ftlbs/9Nm).
- Refit everything, refill and bleed the system.
- 1 week later, remove just the fan and pulley to check the torque of the pump bolts.
Time = 1 hour Task=FairlyEasy
Most replacement kits do not include the paper gasket for the housing. Before you start, get this from BMW (part # 11531721172) or have a sheet of gasket paper 100x200mm (4" x 8") to make one.
- Open the radiator drain and take out ~2-3 litres of fluid.
- Disconnect the 2 hoses from the radiator. Check their condition.
- Four 10mm hex bolts hold the thermostat housing in (they are shorter than the water pump bolts). The thermostat may stay in the head and can be popped out with a screwdriver.
- Install the new one with the spring towards the head (the recess faces with the o-ring).
- Locate the gasket on the housing using the bolts.
- No not over torque the bolts (7ftlbs/9Nm).
- Refill and bleed the system.
- 1 week later, check the torque of the bolts.
Time = 5-7 hours Task= Relatively Complex
At around 100,000 miles (like the M3), depending on maintenance and general use, the timing chain system starts showing signs of wear. The symptoms are the same as the tensioner (see Faults page), but, if after replacing the tensioner, the noise persists then the chain and sprockets must be suspected. The noise is pronounced between a certain rev band - usually 2800-4000rpm and normally gets worse as the
engine heats up.
On my car, my sprockets were worm The timing chain was also micro-pitted on the rollers but had no stretch:
The system primarily consists of a duplex chain connecting the crankshaft sprocket and both camshaft sprockets. They should all be replaced together. There are two long nylon guides which should be budgeted for too - the original design has been modified.
An idler sprocket is mounted above the crank sprocket, but it is not under a strong load and should only be replaced upon inspection. There are two further nylon guides - one above the cam sprockets and one below the crank sprocket; replace only if worn.
As the procedure is quite long, I have had to put it on a seperate page - click here to get to it!
Changing these is easy as the car has no drums!
Safety comes 1st! - some guidelines
- Ensure the car is securely located on axle stands (never a jack)
- Reinstall brake items exactly
- Press the brake pedal a couple of times before driving off to settle things and remember to readjust the handbrake (if applicable)
- Test the brakes immediately after moving off to check everything is functioning
- Torque all fittings correctly, including the wheels
- Avoid straining caliper hoses by supporting them with twine or wire
- Always use non-asbestos pads. If you are unsure of the pad material, hose out the caliper before starting work (obviously don't drive with wet brakes!)
- Remember that it could take 200-500 miles of driving to match the pads to the disc shape (due to wear of either) and many pads need to settle under use - so don't expect full brake performance for some time
- Sports / very hard pads may need to heat up to operate properly.
Time (per wheel) = 15minutes Task=Easy
This is easy enough...
If you come across a wear sensor, simply pull it out of its slot on the inside (piston) pad and replace it the new pad taking care to orientate it correctly. Note that front sensor is held in place with a pin. Once the wear sensor has activiated (i.e. the wear light came on the dashboard) it will have to be replaced by unplugging the old one from its connector at the rear of the hub/caliper and replacing it.
The pads specified by BMW (or Mintex, Ferodo, Green Stuff or Pagid pads) can wear the discs within (depending on use) 60,000miles / 100,000kms. Check that the wear is not greater than 2mm. If you replace the discs, replace the pads too to ensure even braking.
Time per wheel = 30minutes Task=Easy
Get a manual if you want detail but the tips are:
- Spray WD40 on the two 19mm caliper frame mounting bolts and the disc holding (posidrive or 5mm allen) screw.
- Using a large screwdriver, lever the pads away from the disc so that there will enough room to lift off the caliper. Don't forget to support it.
- Loosen the handbrake cables (under the handbrake lever cover) by ~1"/25mm if you are doing the rears and check the handbrake shoes, replace if necessary!
- Take the opportunity to check the brake hose to the caliper for bulging or microcracking.
- Readjust the handbrake cables so that the wheels are locked on the 4th or 5th notch and each wheel is braked evenly (you may want to do the latter on an incline).
- Make sure that the discs are clean before driving on them.
Rocker cover gaskets
Time = 20 minutes Task=Easy
Is you are removing the rocker cover, it may not be necessary to replace the gaskets. They are made from rubber and so, are unlikley to get destroyed on removal. However, is the gaskets are very old they may have deteriorated. Often oil leaks are evident on the cylinder head or into one of the spark plug recesses. Bolts are 11mm hex.
Part numbers are:
11121721876 profile gasket
11121721475 spark plug chamber seal - lollipop shape
11121721476 (3 off) spark plug chamber - O shape
Do not over torque the bolts (7ft-lbs/9Nm).
Time = 10 minutes Task=Easy
Note that the spark plugs in this engine are not compatible with the M40 or M10 engines, being narrower (10mm plug socket needed). A compressable washer is used as a seal. Do not overtorque as there is a risk of stripping the threads (18ft-lbs/25Nm).
The engine is designed to use multi-electrode plugs which have a minimum life of 24,000 miles. The ones specified for the engine are pregapped.
Time = 3 minutes Task=Easy
An in-bowl filter is used. The location ensures that the liquid level is negligible when it comes to changing it.
- When installing the new filter check to see if it has a "top" or other mark indentifying an orientation.
- Check the o-rings on the bowl lid and the base of the 13mm hex head drawbolt. The OEM Hengst filter provides new o-rings and a soft washer for the top of the drawbolt (discard the smaller washer supplied) - there is no harm in replacing them.
- Needless to say, do not leave the bowl open for any length of time.
- Torque to 22 ft-lbs/30Nm.
Gearbox lube change
Time = 30 minutes Task=Fairly Easy
You will need a hexagonal sump wrench (or a 17mm bolt head with a vice grips) to open the filler and drain plugs. The fill plug is on the RH side - you can see my drain plug inserted in the filler cap in the photo.
- You will need to get the front of the car up on axle stands on level ground.
- Put something on the ground to catch dribbles.
- Always remove the filler (upper) cap first. Why? Because sometimes it is difficult to open the plugs so you don't want to take any oil out unless you can be sure of getting some in again!
- Then drain out the old oil.
- Clean the metal particulates off the magnet on the drain plug and replace it
- You will need about 1.2 litres of ATF, use the squeezy bottle type with the long neck. I find it easiest to get 75% of the contents in from beneath with 3 0.5 litre bottles. I then pour the remenants into one bottle. This saves trying to pour every last drop from above the gearbox where there is not much space.
- Keep filling until oil runs out the filler hole.
- Replace the filler cap, etc.
Front wheel bearings
Time each side = 45 minutes Task=Fairly Easy
This is an easy job on the E30. The hub and bearing are in one piece when you buy it. Again the procedure is common enough, I'll focus on any handy hints here:
- Start by placing the car on axle stands and remove the wheels. The stub axle doesn't rotate so you don't have to loosen the hub nut at this stage.
- Popping of the dust cap requires a very fine screwdriver to seperate it from the brake disc.
- Using a drift or punch, tap out the indent on the hub nut.
- You now need a 32mm socket - it is worthwhile to source this before you start the job. It must have a thin enough wall to fit into the hub. Use a breaker bar to loosen it.
- Remove the brake caliper and disc (see above).
- The hub can now be pulled off by hand or with a tap of a hammer.
- Occasionally the inner race stays on the stub - it can be cut off with a dremel tool or pulled off with bearing pullers. It is not a strong interferance fit.
- If you have taken off the splash guard, install it first.
- Drive the new hub on with the 32mm socket. Make sure it drives the inner race. Check the bearing is pushed back against the step on the stub axle.
- No greasing is required.
- Torque the nut to 200 ft-lbs and indent it with a punch or chisel.
- Don't forget the brakes!
- Check that the splash guard does not foul the track rod end and that the brake wiring is not trapped anywhere.
Front Anti-roll Bar
Time = 1 hour Task=Relatively simple but can be a pain in the you-know-what
A common failure over 100,000 miles/160,000 km is a deterioration in the antiroll bar bushings or drag links.
- Put car on very secure axle stands with the wheels off.
- Disconnect the drag link balljoints (see pic at bottom of page).
- Unbolt the bushing brackets. You will need a 13mm socket and spanner.
- Remove antiroll bar to one side of car.
- Prise off bush bracket and remove bush.
- Place new bushes on antiroll bar with the arrow pointing forward (see pic). Put them (obviously) where the marks of the old ones were - I would suggest pushing them rightout to the bend.
- Make up a small amount of water with washing up liquid in it (~2:1 ratio) and apply it to the outside of the bush.
- Put the bracket over the push and tap into place. Remember that the hole is to the rear.
- Feed the anti-roll bar into the car again.
- Get an assistant to support one side. Put the tag of one bracket into its hole and loosely put the nut and bolt into place. If it is hard to get the bolt to meet the nut then use a vice grips to pull the bracket closer to the chassis.
- Check the alignment of the other bracket and move as necsessary. Ensure
the bar is centred overall.
- Connect the second bracket and tighten both. Reattach the drag link (see
Time = 30 minutes Task=Simple
Replacing the drag links is simply a bolt off and bolt on affair (13mm all round). Use a jack to raise or lower the suspension to help align the bolts on assembly - if the wheel is off then it may be necessary to jack the control close to its normal position.
Resetting Service Lights
Time = 2 minutes Task=Simple
There are two indication on the SI display, one for an inspection (back lit) and the "count down" service lights. To reset them you need to make a short jumper wire. I used a 2 Amp in line fuse too - you don't want to risk anything in the engine controls! See the pic for the pins to connect - I tippexed mine to identify them easier.
- Ensure the ignition system is off.
- Remove the diagnostic connector cap on the LH side of the bulkhead
- Identify the correct pins to bridge
- Install the jumper wire
- For an Oil Service reset, turn the ignition on (but do not start the engine) for ~2 seconds. The light will go out.
- For an Inspection reset, turn the ignition on (but do not start the engine) for ~8 seconds. The light will go out.
- To additionally reset the "count down" service lights, turn the ingition on again for ~8 seconds until all 5 green LED's light up.
- Turn off the ignition, diconnect the jumper and replace the cap.
NOTE: Pin 12 of the connector is connected to outout pin 15 of the Motronic unit. This gives the engine fault codes by switching to ground and can be seen by connecting a 5W bulb to +12v. I would recommend fitting a 2A (or less) rapid blow fuse in line too. Do this at your own risk! The list of fault codes is available at the Bonneville Motorwerks Webpage
Wiper motor intermittent sticking fix
Time = 40 minutes Task=Reasonably Simple
Occasionally the E30 wipers seem to stick when in intermittant. The cause can be the control relay (which usually will cause problems at other times too) but this fix is free. The motor uses two contacts to referance when it is at the start/end of its cycle. A circular metal plate has a notch in it which corresponds to the rest position - at which point the circuit between the 2 contacts is broken. This stops the motor.
However, grease from the motor can get onto the tracks and cause poor contact at other points in the cycle, fooling the motor into thinking that it is at its rest position. All that is required is to clean the contact tracks.
- Prise out the LH cover grill. It is sprung at the bottom (front) and held at the top. I used a couple of screwdrivers and folded towel to protect the paintwork.
- Remove ~3 7mm bolts in the panel that runs across the bulkhead. They are recessed, so a socket is best. Some models aslo have plastic screw caps too.
- Remove the weather strip and pull back the panel as much as possible.
- Tippex the motor spindle to the wiper arm and one of the slots in the motor bracket to its bolt for reorientation later.
- Remove the 10mm centre nut and shock the arm off.
- Release the three 13mm hold down nuts. Note the orientation of the splash guard.
- Detach the power cable.
- Lift out the motor via the panel access. It may be easier to release the 3 10mm bolts that hold on the motor bracket - but try not to take this out.
- Unclip the plastic cover over the motor worm drive. You will see the two circular tracks made by the contacts.
- Clean right around these tracks with some methys.
- Put a light clean smear of vaseline or grease on the track to stop it rusting(!).
- Reassemble and reinstall the motor to the bracket. Put everything in position - but do not tighten the 3 nuts on the bracket slots yet. Don't forget the splash guard!
- Realign the wiper arm to the spindle using your tippex marks. You may want to turn on the wipers briefly to ensure it is at its rest position.
- >Now set the left-to-right slots so that the wiper arms are in the correct position at rest. Run the motor to check.
- Tighten all nuts, replace the panel, pop in the grill (bottom first) and pat yourself on the back.
Replacing Track Rods
Time = 20 minutes per track rod per side
Track rods usually wear at the inner (steering rack side) or outer (strut side) balljoints. Wear is usually detected by a looseness in the steering or rattling over bumps in a straight line. There are two rods per side threaded together to facilitate adjustment.
The job is a simple remove and replace but here's some important things to remember:
Aligning front toe
Time = 20 minutes
After doing any front suspension/steering work the alignment of the front wheels should be checked professionally with precision equipment. However, the alignment may need to be set up just to get the car mobile. This procedure can get the alignment pretty close if it is conducted with care.
- Put the car on a level surface - both left to right and front to rear.
- Loosen the trackrod clamps on each side of the car.
- Put the key in the ignition barrel and centre the steering wheel by eye.
- Now get a long piece of wood. It must be long enough to reach from the front wheels to the rear. It must also be straight (I always measure against the thickest part of the wood just in case).
- Now place the wood across the front tyre diameter in line with the centre of the wheel and parallel to the ground - see the pic.
- You now need to adjust the track rods so that the front wheels point at the rear wheels like in the photo. Shorten the track rods to increase the toe in (negative toe) - this has the effect of moving the wood outwards away from the rear wheel. Lengthen the track rods to do the reverse. Note that a 90 degree (quarter) turn on each rod will adjust the toe by about 5 minutes.
- Each time you make an adjustment roll the car forward and backwards a little to allow the suspension/tyres to move to accomodate it. Make sure the steering wheel stays centered.
- The alignment will be fairly accurate when the plank lines up with the outer edge of the rear - as in the pic - but you will need to look exactly down the edge of the timber. I managed to be accurate to 10 minutes of arc with this method.
- Now tighten everything up and get it accurately aligned!
Gearbox rear oil seal & Guibo (flex disc)
Time = 2-3 hours
This article covers the replacement of the gearbox oil seal, but the tasks in doing so are similar to those required to replace the guibo.
Before even dreaming of starting the gearbox seal job, the correct socket for removing the output flange nut must be sourced or made. The following are the important dimensions:
I used a 1/2" drive 30mm impact socket and turned it with a lathe. I then had to drill out the end to make it long enough. The pics should explain it:
- 30mm hex
- Outside diameter = 39.0mm +/-0.5
- Internal length = 70mm at a minimum diameter of 15.5mm
Firstly, get the car of the ground by placing it on axle stands. If you have a lift that's even better. Make sure the car is stable and level. Leave the handbrake off and in neutral.
Neither the exhaust nor the propshaft need removal but they do need to be partially disconnected to create working space.
Start by releasing the rear silencer hangers - 2 off 13mm nuts. Using a screwdriver unhook the rubber support adjacent to the axle. Let it hang down a few inches and support it with something to keep stress off the headers - a paint can or a jack would do.
Now remove the two exhaust heat shields. There are a couple of 10mm bolts around their edges and 4 off 13mm bolts. There are two bolts connecting them together which don't have to removed - they can be removed rearwards as one piece.
Using a vice grips or shifter, loosen the spline clamping sleeve a couple of threads after tippexing a realignment mark. This will allow you to shorten the length of the driveshaft to pull it off the rear of the gearbox. Remove the 2 off 13mm bolts that hold in the propshaft centre bearing. Allow it the rest on the exhaust so as not to put much stress on the universal joints.
Tippex realignment marks on the guibo, damper, flange and propshaft. Remove the 3 off 17mm bolts and nuts (with washers) connecting the guibo to the gearbox. These are easier to get at if the vibration dampener is installed. Using a lever, prise the guibo backwards. If this is proving difficult, check that the spline sleeve is loose enough. The propshaft can be put to one side. The guibo can be removed at this stage if necessary.
Now to the gearbox seal. Study the pics below first to understand what everything looks like. Using a screwdriver, push the gearbox output shaft nut (I'll call it the nut from here!) lock washer in at the 3 recesses in the flange. If you can, pull it out with a needle nose pliers - I couldn't.
Put on the socket. If you couldn't remove the lock washer, tap the socker gently with a hammer to ensure a good seat on the nut. Remove the nut. If it is tight, put the car in 1st gear to resist it turning or put it in reverse while someone pulls on the crankshaft pulley bolt.
Remove the flange using a 3 leg pullers as it is quite tight.
Remove the seal. It needs a jolt to get it unseated. Some people drill and tap a screw into it and pull on this. Some use a hook to pull on it. I used a large pinch nose pliers to lever two points. I put a spanner over the handle of the pliers and gave that a whack with a hammer and it popped out on the second attempt. Be careful not to score the gearbox housing though!
Tap in the new seal so that it is flush with the outside housing.
Before fitting the flange, coat the inside edge with sealant to prevent further leaks. Align the flange on the splines and tap it down gently. Coat the rear of the nut with sealant too and tighten it to 125ft-lbs. Replace the lock washer and punch it outward into the 3 recesses in the flange.
Align the propshaft to the flange tippex marks, slip in the vibration damper and bolt them up. Reinstall the centre bearing, tigthen the spline sleeve to the tippex marks, put in the heatsheilds and rehang the exhaust. Finally, check the gearbox oil level.
Fuel Filter Replacement
Time = 5 minutes
- Firstly depressurise the fuel system by removing fuse 11 and turning over the engine a few times (it should not start).
- To minimise a chance of a spark, disconnect the earth (negative) battery cable.
- Certain books recommend hose clamps but it is not necessary. Simply have the fule tank nearly empty and park the car facing up hill. This minimises any potential fuel drain when you remove the hoses.
- Locate the filter on the left hand inner wing opposite the starter motor.
- Loosen the two large jubilee clips. Slide them will up each respective fuel hose so not to forget them later.
- Loosen and slide back the small jubille clips on each fuel hose. Rotate the hoses slightly while on the filter to make them easier to remove.
- Now get the new filter ready. Find the arrow showing the fuel flow direction.
- It is important not to allow any dirt into the outlet side of the filter (the new one may be capped as a result). So remove the hose going to the engine first and immediately put it onto the outlet on the new filter.
- You can then put on the other hose - be prepared for the fuel coming from the filter and from the hose. Be quick!
- reconnect and tighten all the jubilee clips again, install the fuse and reconnect the battery.
- Start the engine and confirm there are no fuel leaks around the filter.
Propshaft centre bearing replacement
Time = 3 hours
Task=Easy but time consuming
Firstly, get the car up as high as possible on very secure axle stands. If you only have two, lift the rear. Leave the handbrake off and out of gear.
- Start by loosening the rear exhaust box (two 13mm nut) and bend the hangers down. I put a jack under the exhaust to stop it going down too far.
- Unhook the exhaust rubber hanger at the subframe - you can also release the 13mm bolt on the mount.
- Loosen, but do not remove the exhaust support from the rear of the gearbox.
- Remove the exhaust heat shields by taking out the two rear 10mm self-tappers and the 8 13mm bolts. 4 of these are above the middle silencer and you will need a spanner rather than a socket to get at them. Wiggle out the heat shield - sometimes it helps to remove the 2 other 10mm self tappers that hold the front and rear shields together.
- Stick on the handbrake. Put a vice grips or water pump pliers on the central spline clamp - its a little awkward with the exhaust in the way but you should manage eventually. One good shove should get it started. To loosen it further, hold the clamp while rotating the propshaft by hand when you release the handbrake later.
- Pop down to the differential end and release the two 17mm nuts that are visible. Release the handbrake, turn the propshaft so that the other two nuts are accessible, put on the handbrake and remove them. Using a screwdriver, push the propshaft forward a little to release the u-joint bolts
- Remove the two 13mm bolts from the centre bearing mounting.
- Mark an alignment spot on BOTH halves of the propshaft (I always duplicate marks in case they get removed). It is imperative that the both parts of the shaft are put back exactly in order to ensure its correct balancing.
- Now to the gearbox end. You will need both a 17mm socket and spanner. Like the other end, remove all the six 17mm bolts & nuts from the guibo/gearbox end by rotating the propshaft as necessary (it is handy if you have someone to operate the handbrake for you!). Note where the washered bolts go (gearbox) and where the vibration damper (if fitted) is held (propshaft bolts). Note: It may not be necessary to remove both sets - its up to you!
- Push the propshaft rearwards and drop the end of the propshaft down.
- You can now remove the propshaft forwards. I found it beneficial to take it out in two halves, having loosened the spline clamp earlier. If you take it out in one piece, then slide it apart now.
- Remove the spline clamp, circlip and dust washer from the front of the bearing.
- You can try hitting the mount hear the bearing with a lump hammer to get it moving - otherwise use a pullers to remove the bearing from the propshaft. I cut off the outside of the rubber mount to improve access. You can also use a collared pullers to get around the mount if necessary. If all fails, any workshop will have the bearing off in an instant.
- Note that the rubber mounting has a collared extension - this MUST face the shaft (rather than the spline) end. See the picture. Drift on the bearing by ONLY hitting the INNER race. Take care as it is all too easy to hit the dust cover on the race instead. The bearing must seat against the propshaft (the circlip groove will be exposed then).
- Put the dust washer and circlip then the spline clamp back on.
- I would advise assembling the two halves of the shaft now. This is to ensure that your alignment marks line up - there is a risk of having them one spline out if you do it under the car. Hand tighten the centre spline clamp to prevent the shaft seperating when your are reinstalling it.Note that the U-joints should lie the same way.
- Guide the shaft back into the car from the front, watching out for various snag points and ensuring it stays in one piece. Guide the differential bolts back into place and put on some of the nuts by hand.
- Grab the guibo and vibration damper and align them with the other end of the propshaft and the gearbox. The guibo has arrows on it, and these must point towards the flange arms of the propshaft (3 pointing rearwards) and gearbox output (3 pointing forwards). Mount the nuts, bolts and washers as noted on disassembly.
- Loosely remount the centre bearing assembly.
- In the reverse of before, tighten up all the differenential end nuts. Then do the guibo nuts and bolts.
- Rotate the propshaft a few times. Nip up the centre bearing mounts bolts - but still allow the mount to move. Now tighten the centre spline clamp - it doesn't need to be that tight.
- Lastly, push the bearing mount forwards by 4-6mm to preload it. Tighten the two bolts.
- Have fun putting the heatshields back in. Rehang the exhaust and your done!
Differential Bushing Replacement
Time = 2 hours
Task=Easy but needs access to a press
Firstly, make sure you actually need a new bushing by having a close look at it. In the pic below, it is OK for the bushing to have tears at the bottom - its only a thin web of rubber anyway. If there are tears at the side then it has to be replaced.
- Firstly, clean the diff as much as possibly using a pressure washer, wire brush, Gunk or whatever takes your fancy. This is to prevent it falling into the diff when you are trying to remove it.
- Loosen, but do not remove, the 10mm allen socket fill plug - this is done first to ensure you can refill the diff later! Place a container (>1.5 litre) under the diff, remove the drain plug and let out the oil. If you have a LSD you may want to reuse this oil as it is specific to the diff - so keep it clean!
- Remove the bolt and nut going through the bushing - you might need the help of a jack to lift the diff to unload the bolt.
- Undo the peripheral bolts around the rear diff cover. Using a soft face mallet (or a piece of wood with a hammer) tap the cover loose.
- The cover should fall out or may need a little wiggling from the chassis mount. Try not to get dirt anywhere near the internals of the diff. Once off, clean the gasket off the face of the diff and then cover it with a plastic bag or something similar. Now clean up the cover face.
- Now get the rear cover to a hydraulic press to push out the bushing and get the new one in. As the cover is aluminium its probably not such a good idea to whack it out...
- It's simple enough the get it all back together again. Fit a new paper gasket (use a bit of instant gasket to keep it in place) and don't over torque the bolts on the cover (~30 ft-lbs).
Fuel Pump Replacement
Time = 1 hour
Task=Medium (if soldering) or Easy (if not)
This is possibly one of the most dangerous jobs possible on an E30 so safety must be continually kept as Priority 1 . I don't have to tell you that Petrol is highly flammible and its vapours are explosive. Vapours are heavier than air so will fall to the floor and travel in and around the dashboard - therefore opening windows and the sunroof will only have a minor affect on ventilation.
Take these precautions:
- Disconnect the battery before starting this job.
- If possible leave the doors open to prevent a build up of fumes. If the car needs to be locked, use the key rather than any alarm. At the very least, leave the doors open while working in the car to prevent being potentially fatally overcome with fumes.
- Have all tools and equipment ready beforehand and do not rush.
- Use spark proof tools (e.g. aluminium).
- Mop up any spills immediately and remove soaked rags from the car.
- Petrol is hazardous to the eyes and, to a lesser extent, to the hands. Use goggles and rubber gloves.
- Remove the fuel pump fuse and turn the engine over a few times to depressurise the fuel system.
- Turn off the radio, disable the alarm and disconnect the battery.
- To give yourself some space, pull the front seats fully forward and tilt them. Remove the rear seat bench by pulling it staight upwards at its front edge.
- The pump is on the right side - so remove the 4 philips headed screws, take off the cover with its seal. Move the carpet a little to clear the ope.
- Loosen but do not remove the 4 off 10mm nuts of the fuel sender unit in the centre.
- Start by releasing the two electric connections and tuck them out off the way
- Get your goggles and gloves on. Loosen the jubilee clamp on the return hose (the one that comes straight in, without the curve on the pipe) and, using an aluminium pliers, wiggle it off its connection. Immediately put a bolt into the hose and clamp it using the jubilee.
- The supply line will probably be partially pressurised so expect a jet of fuel (which may go towards your eyes). Release this slowly with the aluminium pliers and plug immediately as before. Mop up any spills and remove any cloths or rags from the car.
- Clean the tank around the periphery as much as possible.
- Remove the 4 nuts for the fuel sender unit and lift it up but do not remove it to allow it to drain. Once finished, remove it from the car to a clean storage place.
- Note the postion of the pump and then twist it anticlockwise ~45 degrees to release it from the tank. Lift it gently out while tilting it a little rearward to allow the filter to come out. Recover the o-ring.
- You will now have the assembly in your hand, It is made up of a metal cradle, a filter bag and the main pump.
- If you buy a pump from BMW then you will probably have the full assembly and can skip down to the installation section. If you bought the pump spuriously then you may well have just the pump on its own.
- If you do not fancy your soldering skills then return your pump and go get one from BMW. Ditto if you find that the filter bag on the base of the pump is damaged as they cannot be bought spuriously. Do not reuse a damaged filter bag as any ingress of dirt will quickly cause your nice new, expensive pump to fail! I have heard stories of pumps failing again after 2 days because of this...
- To remove the pump, pop off the filter bag using a flat screwdriver against the cradle. Bend back the locating tabs at the top and wiggle the plastic connection upwards. Snip the wires immediately above the connections on the pump.
- Prise out the pump.
- Strip back ~5-7mm of insulation from the wires. Place the new pump in as before and pass the wires through the connections. Refit the plastic connection and bend the tabs in.
- Check the route of the wires to the pump - that they are not trapped and away from the cradle. Solder the wires in place on both sides of the tab. Triple check the quality and integrity of this work.
- As an additional precaution I built up a layer of epoxy over the tabs to add strength and minimise the chance of disconnection.
- Put the filter bag back on and double check everything. Put the o-ring (check condition obviously) in place - hold it in place with a small amount of instant gasket to stop it being dislodged accidently.
- Carefully manoeuver the assembly back into the tank without getting trapped! It only needs to be turned through ~45 degrees so align the location tabs with the tank. Check that the cradle if flush on all sides with the tank before you turn it. Make sure the o-ring is in its proper position too as it is the only way of preventing air getting in to the tank (explsion risk).
- Loosely reinstall the sender unit. Reinstall each hose one at a time and tighten each jubilee. Final tighten the sender unit. Reinstall the electrical connections.
- Double check the security of everything before reconnecting the battery and starting her up (it will take a while for the fuel system to repressurise). Once OK, fit the cover and rear seat by pushing it down.