Engine Knock/Rattle (VIDEO)

[Superson]

Recently finished installing a re-manufactured cylinder head and the engine is still making a knocking/rattling sound :(. Could it be piston slap? The noise is louder when cold and quiets down a little bit when warmed up but not completely. It does go away at higher RPM. Any suggestions?

https://www.youtube.com/watch?v=yYgUvkmb7Yg&nohtml5=False

[packratbimmer]

First, I would try a valve adjustment and then go from there

[Superson]

I have several times already and used the spring loaded valve adjusting tool from BMW to ensure less room for error. When I did remove the old cylinder head I noticed vertical scoring marks of 3 of the cylinders. They weren't deep enough to catch a fingernail on though. I figured I would continue with putting the new cylinder head on just to see if the sound would go away, but it's still there. I didn't see any metal debris in the oil when I drained it.

[Superson]

I should probably mention that the engine did make this noise with the old cylinder head. However, it was much louder before the rebuilt head was put on. So the new cylinder head seemed to somewhat quiet it down.

[Seawolf]

Do you have a stethoscope ? If not the $5 cheapy from HF works fine in tracking down noises like this.

Did your rebuilt head come with a new cam ?

- and some total wild guesses.....

Does your engine have the recalled pressed metal cam or oil pump gear ? I've heard they make a horrible rattling noises when they crack and start to fail.

How about a cracked exhaust manifold ? Hairline cracks can make some really unexhaust like noises - the noise tends to change as the manifold heats up.

[Superson]

I don't have a stethoscope, I should get one. I believe the camshaft was just reground, it is not brand new. How would I be able to tell the difference between a recalled camshaft and an "updated" one? Also, I haven't heard of either recalls, where could I find more information on those and do they apply to a 325ix specifically or all E30 models with the M20 engine. I'm aware that the oil pump on an IX is different from other E30 models. The car has 230,000 miles on it so it could be the oil pump? The noise sounds like it is coming from the top end more so than the bottom. I got under the car while the engine was running to see if the noise became louder but it is definitely more audible from the top end. I didn't see any visible cracks on the exhaust manifolds when I attempted cleaning them.

[Superson]

Here's a video of the noise when it had the original cylinder head.

https://www.youtube.com/watch?v=LnO2bj2wLvI