E30 timing belt change?

[Rick Lee]

I've heard but not read that the E30 timing belt and water pump need to be changed out every 60k miles. Is this accurate? Also, how tough a job is this? I did a complete clutch R&R in my 911, so I feel emboldened. Any good sources of info for this job and a valve adjustment? Bentley gets some real mixed reviews on Amazon. Thanks.

[KillerDynoSoar]

Does anyone have any information on Ricks question?

I am making a list of things to do and the Timing belt is something that I must do.

Is it hard?

My car is a standard E30 325i S with no A/C.

Any feedback appriciated.

[Johnnyvolvo]

I changed the timing belt and water pump on my 325e a few months ago, i was really dreading to get it started after reading some of the comments of others on this subject. I was really surprised at how simple it was to do after i got started.You really need to allow yourself at least two days to complete the job.

--Johnny--

[Josh at Pelican Parts]

Hey Rick,
The six cylinder E30s had the ominous 50K change interval...OR ELSE. The 60K interval works quite nicely though. Changing the water pump is just common sense. You're working all around the pump to access the belt/tensioner. A new pump is cheap insurance for an expensive motor. A lot of guys do the pump every other belt change (100-120K) This is fine if the system is in PRISTINE order. Anything less...I wouldn't leave it to chance. The labor is straight forward enough, if you're comfortable getting in there, it's all layed out in front of you. Also, it couldn't hurt to do the thermostat & gasket now too.
BMW cooling systems require flushes every other year. Using OEM blue coolant is an important factor here. Many well known anti-freeze brands simply don't offer the same protection the real thing does. Don't forget the distilled water..Not tap (minerals). A properly bled, pressure tested system will allow trouble-free driving for years to come.
Good Luck,
Josh

E30 water pumps

E30 Thermostats

E30 Timing Belts

[KillerDynoSoar]

Wow thanks guys.. i'd better get to it. I was promising to do it since I bought the car.

I just came back from the British F1Grand Prix and smoked a few cars on the way back through the country lanes and that was a bad thing to do. But you know how it is the car drives so good its hard to resist.

Better get that belt changed real soon, with water pump and thermostat. Also gonna flush the coolant system too.

Thanks.

[Wayne 962]

Timing belt replacement instructions:

One of the most important maintenance tasks for the six-cylinder E30 engines is the replacement of the rubber timing belt. As the engine ages, and the mileage climbs, an old, worn out timing belt may break, causing catastrophic engine damage. A broken timing belt typically results in the valves hitting the tops of the pistons, and either bending all of the valves, and/or destroying the pistons. A broken timing belt can indeed lead to the complete destruction of the engine.
As a result, I recommend replacing the timing belt every 60,000 miles, or every 4 years. If you live in a really dry climate (like Arizona), or if you don’t get to drive the car too much, then I recommend increasing the replacement interval. In dry climates, the belts can become brittle and worn much more quickly. If the car sits for long periods of time, the belt takes on the bends and shapes of the pulleys when it was parked. Both of these circumstances increase the likelihood of belt failure.
I recommend that you jack the car up in order to gain easier access to the crankshaft pulley and the lower radiator hoses, in addition to making it generally easier to remove the coolant. Be sure to place the transmission in neutral so that you can easily turn it over. I also recommend that you remove the spark plugs from the engine, as it will make it much easier to turn the engine and sense if you have any interference problems when you place the new timing belt on.
Although not necessary, it’s probably wise to inspect and/or replace your water pump and thermostat at this time. In general, I recommend replacing the water pump every 2nd time that you replace the timing belt. See Project 35 for more information on the replacement of the water pump and thermostat.
E30 cars manufactured in 1986 and later should have a tensioner marked with ‘Z 127’. If your tensioner does not have this marking, then you need to replace it with one that does. This tensioner design replaced and earlier, potentially faulty design.
Follow the procedure documented in the photos for instructions on how to remove the timing belt and camshaft sprocket. Before you install the new belt, install your new (or old) tensioner onto the car, compress the spring as far as you can, and then temporarily tighten the adjustable tensioner bolt (green arrow, Photo 12). When you install the new timing belt, place it on the engine, working counterclockwise, starting from the crankshaft sprocket. Slip the belt over the intermediate shaft sprocket, around the tensioner, and over the camshaft sprocket. Now, loosen both bolts on the tensioner to apply tension to the timing belt. Verify that the timing marks for TDC on the camshaft sprocket match up against the notch on the cylinder head (see Photo 10). With a socket on the crankshaft pulley, carefully rotate the engine clockwise through two complete revolutions (720°). Verify that the timing mark on the camshaft pulley is in place again. Torque the upper and lower mounting bolts for the tensioner to 16 ft-lb (22 Nm).
With the tensioner in place, reinstall the crankshaft pulley and lower timing belt cover. Recheck to make sure that the camshaft sprocket is aligned with the cylinder head when the vibration dampener or toothed timing wheel O/T mark is aligned with the lower timing belt cover. If not, then remove the dampener and the lower timing belt cover, and reposition the belt. Reinstall the front pulley, using red Loctite on the six mounting bolts.
When you’re finished, reinstall the radiator and bleed the cooling system as described in Project 33.

Picture 1: Shown here are all the items that are included with the E30 timing belt kit, and a few additional items I recommend replacing. In addition to a complete set of radiator and coolant hoses, shown here are the following:
A- Air conditioning, alternator, and power steering belt.
B- Water pump.
C- Timing belt.
D- Timing belt tensioner.
E- Thermostat.
F- Camshaft seal and o-ring.

Picture 2: This photo shows the engine compartment of a 1987 E30 325e. Although not requires, when changing the E30 timing belt, I recommend that you also adjust the valves. I have removed the valve covers in this photo for that purpose, but their removal is not required to replace the timing belt. Also removed for this photo is the front hood. Although removal of the hood makes access to the radiator and front of the engine easier, you can perform all of the work with it in place. I removed it for this particular project so that I could photograph the front of the engine more easily. Although you could probably perform the timing belt replacement with the radiator installed in place (yellow arrow), I do not recommend it. Removal is a snap, and makes the job a whole lot easier. Begin by disconnecting the upper radiator hose (blue arrow), and the radiator overflow hose (red arrow).

Picture 3: With a large bucket and some paper towels handy, remove the plug on the bottom of the radiator, and also disconnect the lower radiator hose (yellow arrow). If you are replacing your coolant (recommended), then pull out the plug on the engine block as well and remove the coolant from the block. Be sure to dispose of the coolant properly – it is toxic to children and small animals. Also verify that the engine is cold – when you disconnect the lower hose, you will spill some of the coolant out, and you don’t want to burn yourself.

Picture 4: With the radiator hoses removed, now turn your attention to the radiator mounts, which are located on the left and right side of the radiator. These mounts are removed with a 10mm socket (blue arrow). Inspect the mounts when you remove them – in most cases the rubber will be deteriorated and require replacement (yellow arrow). The photo inset shows the radiator coolant temperature sensor that also must be removed prior to pulling out the radiator.

Picture 5: Shown here is the front of the engine, after the radiator has been removed. At this point, the fan and fan pulley have been removed (see Project 34 for removal instructions). The belts have also been cut off with shears (you should be replacing all of them anyways). The yellow arrow shows the backside of the distributor cap. The green arrow points to the air conditioning compressor. The blue arrow shows the alternator. The red arrow points to the water pump pulley. The orange arrow shows the main crankshaft pulley, and the purple arrow points to the power steering pump.

Picture 6: Here’s a close-up photo of the alternator and it’s supporting brackets. You need to remove the bracket shown here in order to remove the timing belt cover. Begin by loosening the rear alternator bolt – it’s location is indicated by the green arrow. Be careful not to turn the front alternator “pinion” bolt until the rear is loosened. With the bolts loose, remove the nut that holds the bracket to the timing belt cover (yellow arrow). Then swing the bracket out of the way. It’s also a good time to remove the crankshaft sensor – simply pull it out of its bracket.

Picture 7: Now remove the distributor cap. It’s held on with three small bolts. With the cap removed, you can remove the distributor rotor. You will need an XXmm hex key or driver for this task. I recommend that you replace the cap and rotor with new ones when replacing the timing belt.

Picture 8: At this point, you should be able to remove the few small bolts that hold on the upper timing belt cover. The cover should simply slide off, and you will be able to see the upper part of the timing belt. The camshaft timing sprocket is indicated by the red arrow, while the timing belt tensioner is indicated by the green arrow. If you are planning on replacing the camshaft seals (recommended), then I suggest you skip ahead to Photo 14, and loosen up the Torx bolt on the camshaft sprocket now, before you remove the timing belt. If you accidentally cause the camshaft to rotate when the belt is off, then you can possibly bend your valves by pushing them into the pistons.

[Wayne 962]

Picture 9: Place a deep 22mm socket on the center of the crankshaft pulley and rotate the engine until it reaches Top Dead Center (TDC) for cylinder number one. At TDC for cylinder number one, the O/T mark on the crankshaft pulley timing wheel or vibration dampener (green arrow) will line up with the line on the lower timing belt cover (yellow arrow). In addition, you need to make sure that the mark on the camshaft sprocket lines up with the mark on the cylinder head. Since this engine is a 4-stroke engine, the TDC setting shown in this photo may also indicate that the engine is at TDC for cylinder number 6. Check the camshaft sprocket to make sure (see next photo).

Picture 10: When setting the timing, it’s very important to verify that the engine is set at Top Dead Center (TDC) for cylinder number one. This is indicated by the marking on the both the crankshaft, and the camshaft sprocket, shown here. The green arrow shows the thin line on the sprocket that must match the corresponding mark on the cylinder head (yellow arrow). These two marks should line up, along with the mark in the previous photo. Only when these marks are aligned is it appropriate to proceed with the removal of the timing belt.

Picture 11: The front pulley (also called the 3-in-one pulley) is held on with six bolts (green arrow) that can be nearly impossible to see without a mirror. Remove these bolts prior to attempting to remove the front pulley – use a 22mm deep socket and a breaker bar to hold the crankshaft steady while you loosen and remove them with a socket driver. After you get the bolts off, you should be able to easily pull the front pulley off of the crankshaft. Behind this pulley is a vibration dampener (a mini-flywheel) that also simply pulls off of the crankshaft (or a toothed timing wheel on the later cars). Some extensive wiggling, or the use of a rubber mallet may be required to budge the dampener/wheel from its home position. With the pulley and dampener/wheel removed, you can now remove the lower timing belt cover.

Picture 12: This collection of photos shows the removal of the timing belt tensioner. Mark the location of the main tensioner bolt (the one that fits through the slot) so that you can roughly approximate its location when you reinstall it. Using a wrench, remove the bolt that holds the tensioner, and also held on the timing belt cover and alternator bracket (inset, upper left). Then remove the main adjustment bolt for the tensioner, shown by the green arrow in the lower left inset photo. With the bolts removed, you should be able to remove the tensioner and the tensioner spring.

Picture 13: It’s easy to slide out the timing belt once the lower cover has been removed, and the tensioner has been disconnected. This photo shows the crankshaft pulley at the bottom, and the intermediate shaft pulley off to the right.

Picture 14: I recommend that you remove the camshaft sprocket so that you can replace the two seals that are located behind it. These seals have a tendency to deteriorate with age and cause leaks. It’s best to replace them when you have relatively easy access to them. The camshaft sprocket can be removed using a T-50 Torx socket. Use a screwdriver propped up against the cylinder head to gently hold the sprocket in place while you remove the Torx bolt. Make sure that you don’t allow the camshaft to turn, as you can cause the valves to accidentally hit the pistons.

Picture 15: Shown here are the two camshaft seals that I recommend replacing while you have access to them. There’s a small o-ring that fits into the cylinder head (green arrow), and a spring-seal that fits around the rotating end of the camshaft (red arrow). Replacement of the seal is similar to the replacement of the flywheel seal, as detailed in Project 44.

[carman3]

I have done this 3 times on my 1986 325 (owned since new). The Bentley book gets my vote as an excellent resource. I'm a Saturday mechanic and this was the first car I ever changed a timing belt. The first time took the longest because I did not have the proper tools. Two tools are critical which I originally did not have in my box. A 32 mm open end wrench to remove the fan clutch ( I purchased a 32mm bicycle wrench). The second tool needed is a 3mm hex socket. This tool is needed to remove the distributor cap. The rest of the tools I would say any good Saturday mechanic should have in his box. It is possible to do this job without removing the radiator, however if its removed you have a lot more room plus it is not all that much more work. If this is the first time you are doing the water pump and timing belt it will probably take you all day.

[Wayne 962]

I would add the fan pulley holding tool to that list - you can cludge it out without the tool, but it is very useful, and you will probably use it multiple times...

-Wayne

[DrScrub]

Hi Wayne,

Any chance of you posting a link to those pictures as indicated with your procedures?

Greatly appreicated, J

[Wayne 962]

[Wayne 962]

[Wayne 962]

[IRMBE]

I have a 1991 BMW 318i. Is the timing belt rubber or melt. Also I.m blowing 30amp fuses for my electric windows. Does anyone know why this is happening?

[Wayne 962]

Originally posted by IRMBE
I have a 1991 BMW 318i. Is the timing belt rubber or melt. Also I.m blowing 30amp fuses for my electric windows. Does anyone know why this is happening?

Hi there. The four-cylinder engines have a metal chain that connects the camshaft and the crankshaft. In general, the chains last a long time, and don't typically break.

As for your windows, is it both sides, or just one? Sometimes fuses can be blown if the window regulators are all gummed up and causing the motor to pull a lot of current, but this would only happen sporadically, and shouldn't happen with both sides.

Can you describe the problem a bit further?

-Wayne

[IRMBE]

Thanks for your response. The problem is with all the windows once the fuse goes however the windows that seem to cause the fuse to go are the passenger sideone. I've blown 3 fuses in the last week. I once had this problem and a mechanic pressed on the circuit breaker button as well as the window lock switch and the windows worked. Obviously the fues wasn't blown but this time the 2nd fuse in the fuse box keeps blowing.

[jase007]

Wayne:

Nice pics. Looks like a preview to the E30 section of the upcoming book I have a similar photo essay that I was going to post but I like the arrows in yours.

One Q on the cam seal replacement:

Any concern on moving the cam when replacing the cam seal? Did you use anything to hold the cam from rotating? Bentleys suggests some BMW tools, of course, but I thought you might have come up with another solution. I am aware that you can move the cam a little with the #1 @ TDC but, I wouldn't want the cam to move to much. Not concerned on reinstall of the belt as getting the marks back in place relative to the head / block / t-belt cover and marked belt are all relatively easy.

I did see this to break the Torx bolt but was thinking when removing hte seal and housing.

If you are planning on replacing the camshaft seals (recommended), then I suggest you skip ahead to Photo 14, and loosen up the Torx bolt on the camshaft sprocket now, before you remove the timing belt.

TIA

Jason

[Wayne 962]

Nah, the camshaft should be balanced from all six cylinders, so it won't move unless you turn it. Loosen up the nut that holds it on while the old belt is still attached to avoid having a piston / valve mess on your hands...

-Wayne

[hartex1]

Wayne,

You referenced "Project 45" on how to install the cam seals. Where can I find this information.

[hartex1]

Another question on the Cam sprocket bolt (T-50). A friend told me that it was reverse threaded. Can anyone comment? Also do I need to apply Loctite and what is the torque spec on this bolt?

Thanks