e30 will not start, cam not turning, help - BMW Forum

darrynrb · 05-03-2006, 03:50 PM

Hi

Just gave my e30 m40 engine a service, new oil, filters etc. Car was idling and then it just died. Done a bit of snooping around it (im no mechanic), the engine cranks but will not start. I took off the rocker cover and noticed that the camshaft is not turning,so... the engine is cranking, timing belt is in one piece, rotor arm turns but the camshaft doesnt. I know that this is not good...what has happened??? any ideas?

Thanks

and0pand0 · 05-03-2006, 04:09 PM

Well, if the crankshaft is spinning but the camshafts aren't, then it's the timing belt. I dunno if the m40 is interference design, but if it is, you could have a costly rebuild on your hands. Does the crank spin when you turn the key over? If it doesn't, than it could be your flywheels teeth are worn to the point that the starter isn't catching it, and you need a new flywheel.

If the crank spins, the belt/pulleys are fine and it's NOT an interference engine, then I really dunno what it could be.. sounds like a shitty problem though =(

DIRTE30 · 05-03-2006, 04:38 PM

The only thing that I can think of that would cause this is if the connection between the cam gear and the camshaft were somehow severed. I think that the distributor is run off of the gear and not the shaft itself. If what you said is true about the rotor turning and the cam isn't, then I would say you either have a bolt backing out or a dowel missing or broken off of the cam. The dowel is the locator that alignes the camshaft and the sproket. If it breaks off... theoretically you could have the sproket turn without the camshaft! I'd take the distributor off and check the situation out more thouroughly. Did you say that it turn over smoothly? If so I guess that the M40 isn't an interference motor... that or it's too late! I've also had a non interference motor strip the teeth out of the belt before and just spin the crank in the belt. Something else to consider.
Good luck!

darrynrb · 05-03-2006, 06:42 PM

thanks for the reply, like i said im no mechanic so im just going by what i can see. Its really weird cos i checked the cam belt and that seems fine, the rotor arm is definitely moving cos when i crank the engine it spins but no movement in the top section of the engine. Under the rotor arm is a plastic cover, i took that off and there is like a star shaped screw that is quite loose but i doubt that its just that connecting the camshaft. Problem is that the car is probably not worth fixing due to the fact that some lorry driver decided it would be fun to hit me which is a pitty cos the car was in perfect condition.

oh well
Thanks again

DIRTE30 · 05-03-2006, 07:24 PM

Well it sounds like the "star shaped bolt" is your problem. It probably worked itself loose and allowed the gear to slack up and break the dowel pin off! Bummer! I'm sure that it wouldn't be that big of a deal to fix though. By the sound of your terminology for the truck (Lorie), I'm assuming you're overseas. That's too bad, cuz I would have bought the car from you for my lil sis! Anyhow, hope you decide to fix her ol' Charlie! Be a bloody shame to let her go.

saltshaker185 · 05-03-2006, 10:32 PM

haha yess... another semi happy ending...

Starmavin · 05-04-2006, 07:24 PM

Have run accross this problem 3 times before in a bmw and countless times in other makes, if you lost oil pressure at any time longer than 30 sec or more the cam and the head, well, become "one" (friction welded) and snap the cam and/or wood drift key like a twig.

I really hope this isn't what happened to your motor, because it'll cost less to replace the motor than it would to fix it....

At any rate if the crank turns and the cam doesn't you got about a 99.9% chance of bent valves. The M40 is an interference engine. (mostly the exhaust valves)