Please watch my video & please help me with suddenly noisey v8 engine

[632 Regal]

unfortunately the M60 dont need adjustments.

my E30 would sound like that when it needed a valve adjustment lol. i sure dont miss that.

[NU-CATS]

Did you ever find out what the noise was on your V-8

[bimerguycw]

Listen to the head and oil pan with a probe type stethoscope and all 8 cylinders sound the same in terms of camshaft rotation and tapping.

[bimerguycw]

Wouldn't I have a low oil press lite below a certain pressure?

[bimerguycw]

After getting time to perform the compression and vacuum testing here's the results and I appreciate your addition advice on locating actual problem for repairs:

Vacuum:

At idle 650 rpm = 8.5 inHG steady
At 1000 rpm = 10 inHG and steady
I held the RPM's at several levels and the vacuum increased with rpm's and held steady in each case with no fluctuations at each rpm.

Compression:
1 cyl failed...
Tested each cyl 2 times to verify repeatability and values after 4-5 strokes.

7 cylinders = 175-180 psi
1 cylinder = 88 psi (Cylinders on pass side at front of head where noise the loudest.

Any and all advice appreciated now that we have some real numbers to work with, right?

Can we determine if this 1 year old bottom rebuild is okay and it's in the top-end only or what?

Thanks.

[Chris'91'525i]

Compression:
1 cyl failed...
Tested each cyl 2 times to verify repeatability and values after 4-5 strokes.
7 cylinders = 175-180 psi
1 cylinder = 88 psi (Cylinders on pass side at front of head where noise the loudest.
Any and all advice appreciated now that we have some real numbers to work with, right?
Can we determine if this 1 year old bottom rebuild is okay and it's in the top-end only or what?
Thanks.

I would pull the valve cover off on the #1 cylinder side, since it sounded like a valve train problem in your video.
I really doubt any bottom end problems.
I'd Check the rocker arms, damaged cam(s), broken valve springs, bent or sticking valve(s), or bad valve guide. Hopefully it can be repaired and the Cyl. head is not toasted.

Were those wet spark plugs you pulled before on the same side as #1 Cyl. ? , or are they in one of the Cyl's. that had good compression ?

When I did a compression test on my 124K mile, M50 motor they were all at 215 psi. if that means anything, i don't know.

A leak down test would probably be a better test on your motor for a better diagnosis.
I would pull that valve cover off anyway just to check for obvious damage.

[bimerguycw]

Does the comp test with oil in cyl determine if btm or top end problem...I've read about that test but not sure how much oil to put into bad cyl to re-test.

I guess I should pull the valve cover also since I can continue comp tests even then.

I'll report back, thanks for the input.

[bimerguycw]

the compression number look like the other 7 cylinders. I understand this means the cylinder is the leak...either piston ring or cyl wall...crap!

I wonder what caused this 1 cyl to go bad if the btm-end was rebuilt about 1 year ago?

Any ideas out there and how much repair I'm looking at? Can I have the head pulled and ring replaced on this 1 cyl from the top if thats all that was failing or should I suspect more problems and do more repairs to avoid another similar problem?

[bimerguycw]

Did a compression and found 1 cyl low.