M20 gurus help needed

[turbski]

So.... long story short, I have a m20 b27 seta. Basically a complete rebuild. All new bearings complete teardown and rebuild of head. Running ms2, holset hx35 and 14psi. Block head and tune all done by 2 reputable shops.
1100 miles. Did an oil change 2 days ago, the 3rd one. All seemed great until I got into town and could hear a knock or rather pronounced tick at 2k to 4500 rpms. Immediately turned around and headed home. 4 miles.
Pulled the oil pan this morning figuring I spun a bearing but I can't find it. There is very slight lateral movement on all my connecting rods.... like .002". I checked the valve lash and they check out spot on.
I did however feel that the small bearing that holds the drive rod for my oil pump feels gritty and sloppy and the pump itself has a tight spot.
How does one check rod and main bearings properly?
Could the oil pump or support bearing make a noise like that??

[82eye]

did you replace the intermediate bearings ?

was the block hot tanked at rebuild ?

[TobyB]

Exhaust leaks make the oddest noises on BMW engines...

Wrist pins do, too, but exhaust leaks are far more common.

t

[moatilliatta]

If you already have the pan off pull each cap off and look at the condition of the bearings.

But id run it and pull each plug wire and see if the notice changes.

Knock and a tick a 2 different things.

Kinda need more data.

[turbski]

Yes, the block was hot tanked and yes the bearings were replaced.
on the ne 30 Facebook page there is a video of the noise posted under the wife's account.
there is zero noise present at idle. Only presents around 2k and up.
2 things I found. Lower timing cover was loose... . . As well as the cam timing gear.. not crazy loose but enough were I could rock it by hand

[moatilliatta]

Sounds like someone needs a torque wrench for Christmas.

I’d replace the cam bolt if it was ran loose.

[turbski]

Lol good thing I have a birthday soon.

[turbski]

Gonna borrow a friend's bore scope tonight and check out the cylinders for any signs of damage.
I noticed while hand cranking a noticeable amount of compression bleeding off but didn't think much of it ATM.

[moatilliatta]

If the motor isn't broken in there is a chance compression won't show where it should.

[hasa]

Reputable shops?

[turbski]

Reputable shops?

Yes. Reputable. The tuner is an audi nut out of dover. The builder is also out of dover. Specializes in vintage bmw.
the short block and head are all him. The loose cover and cam gear I own. When i... we figure out a root cause I'll post it up. I'm not gonna point fingers or lay blame. This is about fixing another e30. The only reason we are all here.
so on to more figuring and fixing!

[digger]

ticking is unlikely to be bearings, loose stuff that isn't being pound by cylinder / reciprocating forces often ticks

nevertheless to check bearings you'd pull cap off and do a visual if it wasn't obvious they were trashed, just ask the s54/s65/s85 crowd.....what does the oil filter look like when you tear it apart

I'm not sure the intermediate shaft bearings (i.e ones that cam belt idler pulley run on) would knock but they seems suspect there is alot of play and binding, you said those were those replaced so they should be mint. Perhaps you are referring to the needle bearings for the small drive gear?

needs further investigation

can you post a video?

[turbski]

Yes, I'm referring to the small needle bearing on the drive gear. I'll post a video today.
oil filter had a small amount of particulate. When the oil was draining I did see some brass bronze color float to the surface

[hasa]

Yes I know it has no value here to be sarcastic. It's is just that I've seen too much reputable shops. Only few are really reputable.

You haven't yet mentioned if the sound is present only when driving or even when revving the engine without moving. If noise appears all the time (between 2000-4500) you can perhaps locate the source easier by listening while revving the engine by hand. Stethoscope or even wooden stick would be useful here.

I'd say exhaust leak would "tick" more than "knock".

Keep us informed. The root cause will be found for sure.

[turbski]

Yes I know it has no value here to be sarcastic. It's is just that I've seen too much reputable shops. Only few are really reputable.

You haven't yet mentioned if the sound is present only when driving or even when revving the engine without moving. If noise appears all the time (between 2000-4500) you can perhaps locate the source easier by listening while revving the engine by hand. Stethoscope or even wooden stick would be useful here.

I'd say exhaust leak would "tick" more than "knock".

Keep us informed. The root cause will be found for sure.

No worries.
the sound is always there driving or free Rev. I did use the stethoscope but was not conclusive. Seems to be around cylinder 2.
It almost sounds like a Ford 5.4 l with a blown out exhaust manifold. A very loud tick or a light knock if that make any sense