92 E34 M20 Help - Wont Start

[eddie_uk]

Hi Guys,

I have been having an overheating problem which I was working on, topping up, bleeding, looking for leaks etc etc, anyway..........

A few days ago, I started the car OK, turned the engine off to close garage, restarted the car and heard strange crunching noises, not metallic, more plasticky.

Since then the car refuses to start, engine turns OK but seems to be turning faster than normal. Prior to looking for a spark at the plugs, did a compression test, ZERO reading !!.

I have just taken the camshaft cover off to investigate further, and I find small bits of plastic in a recess under the leftmost camshaft (looking from the front).

From checking on the internet I believe that these are remnants of the timing chain guide, turned the engine over quickly and cams, sprockets and chains all turn OK.

Anyone got any idea if the timing chain guide failure would result in the compression loss which I assume is causing the starting problem, or has something more sinister happened.

Anyway, for now taking off the water pump etc for a closer look.

Regards..............

[eddie_uk]

Sorry, M50 not M20

[winfred]

if you are lucky the cams are just out of time, but most likely it bent some valves

[Morgenster]

if you are lucky the cams are just out of time, but most likely it bent some valves

And that would explain zero compression and why your engine cranks fast.
Isn't this supposed NOT happen to an M50?

[eddie_uk]

Does bent valves = new/recon head ????

[winfred]

not really you could replace the bad valves for a good bit less then a rebuilt head


Does bent valves = new/recon head ????

[eddie_uk]

OK thanks for that, if it is bent valves, lets hope there aren't too many