I am posting this in the General Category as my problem could be to any type of automotive and not specifcally my engine etc... Here is the problem... I have 1988 RV with a 460 and C 6 transmission with 22K miles. I have a squeak coming form the engine problem...Her eis what I have done:

- replaced both belts with Good year gatorbacks - tight & all pulleys clean
- replaced tensioner and pulley
-Shop used scope and said noise was from tranny (recently drained, filter and fill) and probably flex plate. Dropped tranny - Flex plate was fine.
- Catalytic converter was bad. Replaced with new factory Ford & all new exhaust.
- No cooling, power steering, leaks, or air conditioning issues. All work great.
- I had right side exhaust manifold redone due to exhaust leak. 3 bolts broke. All fixed.
- I systematically removed alt., air pump and crank belt - Ran and still squeaked the same.
- I removed other belt, power steering, air compressor, water pump & crank. Ran engine briefly.. Still squeaked. So I have rule out any belts pulleys, except Harmonic???
- Had transmission shop relook at tranny and they said no issue other than small leak

WHAT AM I MISSING? The squeak is very loud and annoying... No perofmrance issues that I can notice........

Any suggestions is appreciated. I would think that if it were the clutch fan etc.. it would have stopped when I removed all belts......

I am stumped!!!

 

is this a continuos squeak? have the motor mounts been checked? is the squeak metalic in sound? hmmm it still happens with all the belts off....is the timing mark pointer touching the harmonic balancer?

 

Is it at crank speed, cam speed or valve speed?

Had a misaligned rocker stud that squeaked terrible one time.....

My guess is when you find it, you will find a mess.

Can you pull the valve covers?

If you find nothing, put a couple of small magnets in the where the oil drains...make sure they don't block the oil drain.

Try a magnetic oil plug.

Run it an take a look see. If there is a problem like mine, you are going to find the magnet closest to the problem looking like a fur hat.....

 

Have motor mounts been checked - No I was wondering about this myself as prior to squeak appearing I had right side exhaust manifold redone as it leaked. In order to get three bolts out that broke, the shop had to jack up motor to get access..... Cold motor mounts cause a continuous squeak. The noise speeds up with acceleration but does not get louder, hard to hear over motor at higher RPM's.

Is the timing marker hitting harmonic balancer? This may be out of my league as I am not sure about timing etc...I cannot see anything hitting harmonic balancer.....How should i check or what should I look for...........?

Is the noise in tune with it valve, cam or rocker changes. I really can't say. It goes faster with acceleration, but not louder. Engine seems to perform fine.....

 

OK, if it goes faster with engine rpm, it is probably a moving part, vs. a vibrating part like a motor mount.

Next thing is it's frequency. If you have a timing light, you can get the frequency of the crank rotation and see if the noise matches up to that.

1/2 that is cam speed and valve speed.

Have you used a stethoscope up and down the valve covers?