M20 Engine problem!!! Help!!!

[wiggy1406]

Here is where i am now.

TDC set on camshaft and crank.
Loosened the Head and the crank turns
Set everything to TDC
Tightened up the head
installed cam belt
Crank won't hand turn

Any ideas??

[E34-520iSE]

Do you mean the crank won't budge at all? Will it turn a little bit until you feel some resistance? Have you removed the spark plugs and tried again? What marks are you using for TDC? The cam pointer lines up with the 'dot' on the cylinder head and the crank pulley lines up with the line in the middle of the 'O T' front pulley wheel marking and the raised section of the aluminium crank position sensor bracket.

HTH,

Shaun M

[wiggy1406]

Do you mean the crank won't budge at all? Will it turn a little bit until you feel some resistance? Have you removed the spark plugs and tried again? What marks are you using for TDC? The cam pointer lines up with the 'dot' on the cylinder head and the crank pulley lines up with the line in the middle of the 'O T' front pulley wheel marking and the raised section of the aluminium crank position sensor bracket.

HTH,

Shaun M

Yes and yes on the timing and the crankshaft won't budge at all...does when the head isn't on.

Mike

[whiskychaser]

Did you make a physical check that no 1 piston is at TDC? (Stick a piece of dowel there if you cant see the piston crown.) Did you make sure the valves on no 1 were closed (the lobes should be pointing up and slightly towards each other on the M50 but double check for yours) If you are using the cam sensor pointer as reference is it on the right way round? None of above intended to insult your intelligence but it seems likely your valves and pistons are coming together doesnt it?

[wiggy1406]

Did you make a physical check that no 1 piston is at TDC? (Stick a piece of dowel there if you cant see the piston crown.) Did you make sure the valves on no 1 were closed (the lobes should be pointing up and slightly towards each other on the M50 but double check for yours) If you are using the cam sensor pointer as reference is it on the right way round? None of above intended to insult your intelligence but it seems likely your valves and pistons are coming together doesnt it?

No1 cyl is fully up and both No1 cyl valves on the head are shut. buggered if i know why it jams!

[E34-520iSE]

I'm baffled with this one. Has it dropped a valve? Is there something small (nut, bolt, screw, spring etc) physically stuck between the head and one of the pistons? Is the cylinder head the same one that you took off? Why was the head removed in the first place? Is the headgasket the correct one for the 2.5 block, and correctly lined up? Is something jamming the camshaft when the timing belt is on?

Cheers,

Shaun M

[Blitzkrieg Bob]

Here's a ggod link

http://www.pelicanparts.com/bmw/techarticles/101-Projects-20-E30-Timing-Belt/101-Projects-20-E30-Timing-Belt.htm

[Ross]

Will the cam turn? All I can think of to suggest is that you are feeling compression.

[wiggy1406]

I'm baffled with this one. Has it dropped a valve? Is there something small (nut, bolt, screw, spring etc) physically stuck between the head and one of the pistons? Is the cylinder head the same one that you took off? Why was the head removed in the first place? Is the headgasket the correct one for the 2.5 block, and correctly lined up? Is something jamming the camshaft when the timing belt is on?

Cheers,

Shaun M

I think i might have got to the bottom, the head was recently changed (by me), thene the new head gasket went. Hence this job. There is an iteresting difference between the old gaskets and new one....i.e there is only one locating dowel hole on the old ones, but two on the new one. i think the person who had the car before me replaced the head gasket and removed the location dowel 'cos there wan't a hole for it.....well now there isn't. i think i may have been just lucky when i changed the head, and got it on nearly perfect. However this time i need the two dowels to locate the head perfectly.

Now i need to get hold of the necessary dowel....and new head bolts 'cos i've torqued these a few times.....

Does this sound feasable?

Mike

[wiggy1406]

Here's a ggod link

http://www.pelicanparts.com/bmw/techarticles/101-Projects-20-E30-Timing-Belt/101-Projects-20-E30-Timing-Belt.htm

Thanks Bob

I can now take off and replace the timing belt with my eyes shut....a little fed up with doing it to be frank!

Mike

[E34-520iSE]

You can get away with 1 locating dowel Wiggy, that's not your problem. Two are helpful but not essential. Are the new head bolts the same length as the old ones? Are you using the correct washers on the top of them? Any chance U can whip that head off and post a couple of pics showing the pistons at TDC (1 & 6 up) and the underside of the cylinder head at TDC?

Cheers,

Shaun M

[wiggy1406]

You can get away with 1 locating dowel Wiggy, that's not your problem. Two are helpful but not essential. Are the new head bolts the same length as the old ones? Are you using the correct washers on the top of them? Any chance U can whip that head off and post a couple of pics showing the pistons at TDC (1 & 6 up) and the underside of the cylinder head at TDC?

Cheers,

Shaun M

I'll take the head off again and take some photos, but 1 and 6 are fully up at TDC and 1and 6 valves are shut, if i loosen the head bolts i can turn the crank (with belt on and i can see the piston pushing the head up very slightly, if it's not the dowels, the only other thing is i need a thicker gasket because the head may be over machined.

Mike

[E34-520iSE]

Aha! The head's been skimmed - that could be the problem. There is a lip somewhere on the M20 head which shows the limit of skimming (can't remember where it is now - and my spare head's not handy). If your head's had too much taken off then it's thicker gasket time.

HTH,

Shaun M

[wiggy1406]

Aha! The head's been skimmed - that could be the problem. There is a lip somewhere on the M20 head which shows the limit of skimming (can't remember where it is now - and my spare head's not handy). If your head's had too much taken off then it's thicker gasket time.

HTH,

Shaun M

Thanks ...off to find a thick gasket now!!

[wiggy1406]

Finally got a thick Head Gasket.....and low! the engine hand cranked!!!!.....so i re-assemble the engine.....start her up.....lovely then she splutters and stops!....there was foam inside the rocker cover.

Turns out when one of the eccentrics sheered off, it went and punctured the head in a place that let all the water into the rocker cover........

So i have left the car in my garage until i can get the energy / cash together to weld the head or get yet another one......or i may just sell the damn thing!!

B*ll*cks!!

[E34-520iSE]

Oh what a real shame. If you decide to break it let me know cos there's a boatload of 525 bits that I'm after - you might only need to add a couple of hundred pounds and get yourself an M50 powered 525!!

ATB,

Shaun M

[wiggy1406]

Oh what a real shame. If you decide to break it let me know cos there's a boatload of 525 bits that I'm after - you might only need to add a couple of hundred pounds and get yourself an M50 powered 525!!

ATB,

Shaun M

For a couple of hundred you can take it lock stock (5 months Tax, 7 months MOT) and barrel.

Mike