Knock knock

[Gabor]

Plenty of oil in the head.
Took the timing cover off and everything seems ok.
Checked compression

150
150
120
120

Stethoscope like I taught is useless. No matter where I stick it, it knocks.
Not sure if I should pull the head or the oil pan again to check on the main bearings first.
I have never heard the mains sound like this though.

Any more ideas?

 

[Gabor]

I figured I'll upgrade this just in case somebody one day might have the same problem and since there is nothing in the archives with similar issues.
I took the timing cover off, cut the balance shaft belt and bamm the knock is gone. Didn't tear into the engine yet, but it's obvious that the lack of oil screwed up the balance shaft bearing and that caused the problem I was having.

 

[ktmrider]

Quoting Gabor:
The marking on the bearings are D9F
Are these standard or over sized?

You ever get any info on this Gabor? Took down the donor JDM engine tonight, all rod bearings are D9F. Mains are D9L-H, thrust main is 9H-N.

BTW one rod bearing was down to copper. Main thrust bearing center was pretty raw but crank looks OK. BTW this motor sat for 6+ years before being reborn however he didn't replace/inspect bottom end.

 

[Spyder]

i had a similar sound like that from my engine I just took apart. I thought is was bad lifters at first. I took the valve cover off and saw one of the rollers had fallen out and was laying in the head. The roller had seized and cracked and the cam lobe was smacking the roller so much the roller had a flat spot worn into it and the cam lobe looked like someone took a hammer to it.

 

[rdomeck]

I now own Gabor's car. I drove it 400 miles after purchasing it and the timing belt tensioner failed. When I took it apart I found that the balance shaft bearing had came out of it's bore. It was sort of a good thing that the timing belt tensioner failed ( or I think the bolt was loose ) because I didn't realize I was running around with #3 rod bearing not getting any oil. It didn't hurt the crank and was still able to install standard bearings.