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Discussion Starter #1
Hello,

I put a head on my 2012 1.4t and the head sits 1/16" lower then the timing cover where the head and timing meet right where the valve cover would sit.

The place I bought the head from told me just to machine the timing cover. I would machine the bottom if possible put it sits in place by guide pins and all the bolts.

Thoughts on what to do? I'm trying to get the head shop to replace it along with all the gaskets and the head bolts. But no response yet.
 

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I did xtreme revolutions boost leak test and soapy water and major bubbling around the valve cover gasket only at this point that I can tell.

I tried extra grey rigid rtv to kind of build it up but it just pushed it back out.

Question would this leak cause the underboost code eventually?

I have no p0171 anymore but I'm not going to drive it until I figure out how to get boost. Right now when accelerating and pedal pushed to floor scan tool shows rising to 17psi then it drops back down to 15 and rpms rev like it's in nuetral but car not accelerating. It's an automatic. It'll just keep having the tach go up to 5500 plus but I don't want to damage anything so it's parked till I can figure it out.

Thank you for your support.
 

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Did some research and pulled remanufactured/mach head back off and noticed differences.

The place I bought the head from agreed to take it back full refund but completely berated me about remove and replace procedures. I use alldata mainly but other resources also and they all show no need to take timing cover off to change head but he said I was a "butcher " and didn't know what i was doing.

Not boasting but 30 years automotive experience, ASE certified and well just confident in my abilities. I'm just not a master at these cruze turbos.

Found the head machined a whole 1.++mm off the bottom from removed original head. I also found after cleaning oil off to send back the parts cleaner had removed silver paint the machine shop applied to make it look nice had covered two cracks in two oil passages.

So with this I found part of my issue. The cam cover would never seal properly because the top of the head sits 1.++mm lower than top of timing cover.

20190919_161108.jpg 20190919_161113.jpg 20190919_160828.jpg 20190919_160814.jpg
 

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Found the head machined a whole 1.++mm off the bottom from removed original head. I also found after cleaning oil off to send back the parts cleaner had removed silver paint the machine shop applied to make it look nice had covered two cracks in two oil passages.

So with this I found part of my issue. The cam cover would never seal properly because the top of the head sits 1.++mm lower than top of timing cover.
1mm is about 40 thousandths of an inch. Is that considered excessive for milling a head?

I can't comment about the workmanship, the apparent cracks or installing it without removing the cover, but surely you're not the first person to put a machined head back on an engine like this. There has to be some established way to make the cam/timing cover(s) line back up. That is, with any head from any machine shop, that will be an issue, no?

Doug

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Discussion Starter #6
The way the timing cover on a Cruze is made has to line up exactly horizontally flush or the cam cover will never seal properly, so with this design and a whole mm taken off the head sits 1mm lower than timing cover. There is no way to seal it properly.

It's a design flaw. Typically these won't have 1mm machined off the bottom more like. .05mm or .1mm. Even .25mm is alot to be machined. "My opinion"

I looked into every option before having to send it back. Luckily it worked out this way because when cleaning I found the cracks that were hidden by paint.
 

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It is fortunate you were able to return the defective head. Good luck with your rebuild.
The way the timing cover on a Cruze is made has to line up exactly horizontally flush or the cam cover will never seal properly, so with this design and a whole mm taken off the head sits 1mm lower than timing cover. There is no way to seal it properly.

It's a design flaw. Typically these won't have 1mm machined off the bottom more like. .05mm or .1mm. Even .25mm is alot to be machined. "My opinion"

I looked into every option before having to send it back. Luckily it worked out this way because when cleaning I found the cracks that were hidden by paint.
 

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Thanks for posting the pics. How big is that piece? Does it cover the entire front of the engine? That is, how much work is it to remove it for milling? I'd hate to take everything off the front of the motor.

Doug

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The timing cover can't be milled. It is easy to remove but sits on front of engine guided on with guide pins with zero tolerance to move up, down, left or right. Yes it covers the entire front of engine.

I mean you could mill it if you had the cad specs from gm and proper axis miller or cnc. 170447295.gif 170447502.gif
 

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So today I took it to a semi-local machine shop that a local dealership uses. I showed him the pictures and we discussed it. He was amazed that with the two cracks and the bottom of the head being machine 1++mm off the bottom that they would still try and sell it. This machine shop says that typically only .005 would get taken off and .010 would be considered a lot, is the way he explained it to me. So the original seller took off 8 times the amount that this machine shop said they typically take off of this specific head.

Luckily the seller accepted the return. Now to wait for them to reman the original head that came off the vehicle. Fingers crossed it all works out.
 
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