No compression - wtf?

[632 Regal]

correct, pull the head and make sure before you buy a new one.

Thanks for clearing that up. My guess is the inlet valve heads are larger and they took a hit whereas the exhausts may have escaped.

[whiskychaser]

correct, pull the head and make sure before you buy a new one.

Yep. First job has got to be see what damage has been done.

Will post the outcome. Meanwhile thanks to everyone for support

[whiskychaser]

Just read this article about removing cams. This guy reckons you should be able to spin the cam followers if the valves are closed as there is a small gap between the follower and the cam. I thought there shouldnt be a ANY gap. I dont call 25 thou a small gap. 9 or 10 on an old style head maybe. Either way the head is coming off.

http://www.pelicanparts.com/BMW/tech...ft-removal.htm

[Ross]

The hydraulic adjusters take up the "lash", without oil pressure they ought to spin. 25 thou is a lot, chances are a bent valve is dangling open a bit.

[632 Regal]

IDEA!!!

hook up the compression tester to compressed air to see if the valves are actually open when the lobes are not holding the valves open.

Dont know why I didnt think of this sooner.

[whiskychaser]

IDEA!!!

hook up the compression tester to compressed air to see if the valves are actually open when the lobes are not holding the valves open.

Dont know why I didnt think of this sooner.

To be honest I had thought of that but I dont have access to comp air where the car is. I believe it works in principle as I heard Ford in UK used to use comp air to hold the valves up (closed) while they changed valve stem oil seals. Saved them taking the head off. My only concerns are locating the block drain and if my torx sockets are thin enough to get at the head bolts. Oh, and the price of the parts:£80 just for a head gasket?!!!

[Ross]

Fire up a big ole cigar and blow the smoke in the cylinders through the plug hole and see if it comes out the intake. Okay maybe that's a bit primative. It might work.

[632 Regal]

smoke bombs?

Fire up a big ole cigar and blow the smoke in the cylinders through the plug hole and see if it comes out the intake. Okay maybe that's a bit primative. It might work.

[grave77]

but he has to remove the intake manifold to see it right away. I guess since he fixed the timing before it's better he removes the head and work with eyes open, we are all assuming things and it can all be seen when the head is removed.

[whiskychaser]

I'm going to try the 'cigar test' but as I dont smoke cigars it will have to be cigarette smoke :-) I will just get someone to press the throttle to make sure the butterfly is open. I realised my lady bought one of those jump start kits that incorporate a compressor for pumping up tyres. Its useless for starting a car but I'm going to try check for compression with it as suggested.
Then I'm going to take the head off