The ZHP transplant into my e46 wagon has been...a bumpy road.

[Sean]

Anyways, I won't get into much detail right now - will add more later. I am new to ZHP Mafia, but not new to BMWs. Have a 95 M3 and 88 325 (stroker in 07) that I have had for as long as I can remember. I digress though.

I recently dealt with a hole in a valve on my wagon's 95k young engine (no clue why): http://forum.e46fanatics.com/showthread.php?t=1124176

In order to make the most of a shitty situation, I used that as an excuse to source a ZHP engine and a 6spd trans. I was VERY careful. Drove to Chicago, brought a bunch of tools with me: air compressor, leakdown tester, camera/scope. I inspected my prospected ZHP engine with a fine tooth comb. 160k miles (more than I'd like), but the leakdown passed VERY strongly. Something like 2% loss on each cylinder. Engine seemed well cared for (very clean), no cracked boot, etc. So, I bit the bullet.

Fast forward to getting home, I decided to hook up a battery and "bench" compression test it. In the matter of weeks, I lost compression on cylinders 1, 3 and 5 (ranged from 40-95). This had me at a complete loss. Cylinders 2, 4 and 5 were at 193, 190 and 200 respectively. Did leakdown, found exhaust valves on "bad" cylinders leaking for some reason.

I let it sit as I dealt with other things. The other night I took the valve cover off to ensure no issues. Nothing prevalent. Did another leak down. Now ALL cylinders are leaking during my leakdown testing. W T F?

My only guess is the valves are not closing all the way? Maybe oil in the hydraulic lifters or something?

So, I begin dismantling the head. Got my exhaust cam off tonight and journals 3-6 all have some nasty marks on them! One of the advantages of the ZHP engine is the cam. But, after seeing these journals, I'm really concerned. Is there anything I can do to fix them?

Will post pictures tomorrow.

Discussion commence!

-Sean

[Dave1027]

You should repeat the leak down test but this time squirt a little oil in each cyl. That will tell you if it's ring related. You know these engines have issues with low tension rings. Remember this:

[Sean]

It's not the rings. The air is plainly coming out through the exhaust valves.

I had also checked it right before purchase, applying no oil, and it did not leak into the crank case at all.

But, since I am damn near taking this engine completely apart, I will be putting in new rings now. LOL (using M52 style of course)

[Sean]

Here's some pictures of my poor exhaust cam.

[Oli77]

What causes this wear?

[Vas]

Ouch.

[nextelbuddy]

yikes, what the heck causes that kind of wear/damage? low oil? contaminants getting into the system somehow, improperly torqued cams??

my condolences to that :/

[Sean]

Thanks for the condolences. I only bought it like this. :-\

My assumption is it was starved.

I think it may be polishable. I'm going to swing past the machine shop soon.