Mechanics

CYLINDER HEAD REBIULD - NOISE

1989 BMW 325

Engine Mechanical problem
1989 BMW 325 6 cyl Two Wheel Drive Automatic 100000 miles

Broke timing belt. Sent head off for rebuild. Mechanic said pistons had no damage. Mechanic installed rebuilt head and the engine is now incredibly loud (sounds like a diesel). However, the engine runs smooth and has more power than before the rebuild.

The noise is continuous and loud at all RPMs and whether the car is cold or warm.

What is the most likely cause of this noise?

Thanks!
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Dgatlanta
May 30, 2009.




The problem is that noise does not transmit well in cyberspace and I don't have any idea what noise you are focused on. I have replaced many cylinder heads after cam belt failure and none of them made noise afterwards like what you describe. There is a possibility there is something wrong and it could be anything from wrist pin noise to bent connecting rods to rod bearings. I am a bit dismayed that the tech you chose to do the cylinder head replacement has no input.

Dr. Hagerty
May 30, 2009.
My tech thinks there is something wrong with the head. Of course, there is no way to tell if there was lower engine damage with the head off.

Unfortunately, this is my girlfriend's car and she is in another state from me right now.

I'll have to call the guys who rebuilt the head, Cylinder Heads International in Texas and talk to them about whether it could be the head. Is it possible that a head can be as loud as my girlfriend is describing?

I appreciate your response.
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Tiny
Dgatlanta
May 30, 2009.
As I was consulted after the work was done and I cant be there with you, there is a possibility the head is suspect, usually the head gets damaged after cam belt failure and I usually just go to the salvage yard and obtain a replacement, so if there is damage then the head should have been checked by the rebuilder, if that did not happen then its going to be time to make a decision as to what to do, redo the work or remove the head to search for the issue or?

Dr. Hagerty
May 30, 2009.

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