A few questions on a Timing Belt change..

[G-Bear]

I plan to change my timing belt soon. The engine is an M20B25 in a 1991 touring.

I also plan to change the water pump and adjust the valves at the same time. So far the parts I have are..

Belt and tensioner
Water Pump and gasket
Coolant.

Having read various bits there are a few extra bits I plan to replace and just wanted to check that I've got/need all the additional bits...

Rocker cover Gasket 11121730229
Timing tensioner spring 11311267746 (number 18 in the first pic below)
Camshaft seal 11121285609 (number 12 in the second pic)
Camshaft O ring 11121265087 (number 13 in the second pic)

D Shaped rocker shaft bung 11331264519 (number 13 in the third pic)

How many of these D shaped bungs do I need? From what I've read are there two at the end of each rocker shaft? Four in total, should I replace all four or just the two at the front?



I read in Andy's E30 Bible that its an idea to buy two spare clips that secure the TDC
sensor cable to upper camshaft cover as they tend to break.. Could anyone point out where they are on the real OEM? I can't find them.

Is it worth getting a new crankshaft oil seal too, just incase or is it unlikely that I'll need it. I can't say that I notice any oil weeps from the bottom of the engine.







Many thanks..

[maggspower]

You will need 4 D shaped bungs.

http://realoem.com/bmw/showparts.do?mod ... g=11&fg=10

No. 13 in the above link. These are the clips you need

If there is no leak, leave the crank seal alone. They are usually fairly reliable.

HTH

[G-Bear]

Excellent thanks magspower I must have looked at that pic you just linked about 20 times and not notice those little clips. I haven't got the car at home currently so couldn't go look in the flesh.. thanks again.

[Cloggy Saint]

You'll want #14 too.

[G-Bear]

You'll want #14 too.

from maggspower's link?

[Cloggy Saint]

Yes.

[G-Bear]

Thanking you..

[G-Bear]

I'm just about to do all this work tomorrow...

A quick query about the cam oil seal and its O ring; I assume this shall have to be replaced once I have the timing belt off as the cam pulley needs to come off to get to it. I take it I have to be extremely careful not to turn the cam shaft in the process, does it turn that easily?

If the seal doesn't appear to be leaking is best just to leave it well alone?

Also this seal and the 4 D shaped seals in the cylinder head are said to ensure the new ones going in are well lubricated.. Is engine oil sufficient?

[Rtaylor2208]

Personally I would leave the cam seal alone if its not leaking.

[daimlerman]

I'm just about to do all this work tomorrow...

A quick query about the cam oil seal and its O ring; I assume this shall have to be replaced once I have the timing belt off as the cam pulley needs to come off to get to it. I take it I have to be extremely careful not to turn the cam shaft in the process, does it turn that easily?

No,there's some mechanical friction to overcome first.

BUT

I would turn the crank a quarter turn anti-clockwise(backwards!)with the belt off,this will bring all pistons to the mid-way position,thus avoiding any potential valve/piston action.
Cam oil seal is always a good option to replace whilst you have the thing in bits.
Do not forget to re-align crank and cam before fitting that nice new belt,then release the belt tensioner,turn the engine BY HAND two complete turns and re-check the timing marks.

[G-Bear]

Cheers gents..

[Brianmoooore]

Personally, I wouldn't go near the cam seal if it's OK, but if you intend to take the cam pulley off, crack off the torx bolt before you take the old belt off.
If you need to slacken/tighten the bolt while the belt is off, wrap the old belt right around the cam pulley, and hold the belt with a pair of mole grips. DO NOT hold the teeth of the pulley with anything, other than the old belt.
Note what Daimlerman says about moving the pistons down the bore, if there is any chance of the camshaft turning the slightest amount.
Before you fit the belt, turn the cam to the exact correct position first, then bring the crank to the correct position.

[G-Bear]

Got it all changed today. The d seals in the head were straight forward. The cam seal took a bit of persuasion to come out but the new one popped in quick enough. Thanks for your help gents.