This motor is pissing me off!

[Rhino]

Ok well today i got around to removing the head. I got in there and to my surprise the head gasket looked fine. So did the head its self. So at this point i am very confused. I tried checking it with a striaght edge and it seems to be ok.

Here are some photos.










My syptoms are as follows OVer heating, Poor to no circulation. The motor was severly over heated once. I thought it leaked a little water on side of the head next to cyclinder 2. I tried to bleed the system by opening the vent on the radiator. It just keeps pumping air out. The previous 1-3 Cylinder has 130 psi, 4 cyclinder has 175. Any ideas would be great.

IIT has a new radator and cap and the previous owner said it has a new ater pump and thermostat and New Hoses.

Any help[ would be great i have very little time to make this car run.

[Rhino]

Bump

[abepark]

I would get the block pressure tested.

[rs4pro3]

looks like a problem with the gasket between 2 and 3 on the exhuast side, see how the head is blacker in those spots, and the exhuast valves are a different color.

[kenika65]

That head gasket was blown in the middle two cylinders so just clean it up and put it back together with a new Hg and head bolts, whall your at it I would get the head cleaned up and re grind the valves.

[The Barvarian]

Any ideas as to why #4 was 175 on compression?

[kenika65]

Any ideas as to why #4 was 175 on compression?

??? if you are talking about this motor then 175 is good compression which means that the head gasket isn't blown and the valves arent burnt. And in this case #4 is blown. 2 and 3 are.

[KenC]

You should be up around 190-200 for good compression. 130 is way too low for combustion on these motors.

[Rhino]

What parts besides the head gasket would get me back the compresion i am missing?

[e30pq]

I agree. It looks like cyl 2 and cyl 3 are leaking.

I also agree that you should have a machine shop check the head. If its time for a valve job you might as well do it. If not, you should have them check for cracks and deck the head just to confirm that it's true.

[Rhino]

How can i get back the missing compresion

[KenC]

How can i get back the missing compresion

You need to determine what's causing the compression leak first.

Have the head pressure tested, and see if that's causing it. It looks like 2 and 3 are leaking. If the head turns out fine, then slap another gasket on there and mount it back up. If pressure is still low, then it's your rings.

[Rhino]

I got my anwser i think.

I am welcome to plenty more comments and ideas!

[Fidhle007]

You should have that head rebuilt, it's probably warped. Have it decked and the valves redone, then clean up the top of your block a bit and I'm pretty sure you'll have fixed the problem. BMW bottom ends are pretty stout but DOHC heads warp/crack like a motherfucker.

[Fidhle007]

That head gasket was blown in the middle two cylinders so just clean it up and put it back together with a new Hg and head bolts.

Go back to your rice cars and stop spreading misinformation. BMW headgaskets are much sturdier than those of other companies that "blow headgaskets" and when you have an issue like this it's a problem with the head. If it's not cracked, it's warped. Get it decked, valves done and clean up the block. Putting it back together with a new gasket is something that would be done by someone to who paints a motor and calls it rebuilt.