MarkRobinson

I'm on an island here. Moving this week, lost my best dog last week, work deadlines & conflicts, buying property, selling my house, leasing another, COTA for 4 days straight, very little time to think/rest/study.

Built a 32v motor and installed (7th motor I've built) & have a horrific squeal who's source continues to elude me.

So far I've checked the following: oil filter, oil pressure relief valve, oil pump orientation (of the rotor), all idlers/bearings in front of engine, R&R'd the intake to ensure no hoses were split, checked for clogged fuel return line, fuel pressure, fuel pressure regulator (suspect), vacuum, waterpump (for noise), etc. There are no accessories connected at all.

Here's a video:


Last night I replaced the FPR with another nearly new unit & topped off the fuel, still have the squeal. My stethoscope's only lead is the FPR which is 2x as loud as everything else. Only the Fuel pump and clutch release bearing have not been studied. I need to hit the Fuel dampers too since there's noise from the FPR.

If you have any leads, feel free to list them.

Mark

SeanR

Dang, first I've seen of the vid. When you said you had a squeal you were not kidding. I'm amazed that it can't be isolated better. Go to the trunk and pull the fuel return line, add some line and put it in a bucket. Start the car and see if the pitch changes. Pinch the line and see if there is a change there and it will let you know if it is fuel related.

Oh, meant to ask, if you jumper the fuel pump does this occur then also when the engine is not running?

MarkRobinson

Thanks Sean, I did that already at the FPR itself (bypassed the entire return route). I did not pinch the line to listen for pitch changes. Yes its' quite loud, maybe 85db just above the motor??
Mark

Mongo

I know you had mentioned no hoses were split, but when I did my intake manifold service, I heard an utterly disturbing squeal too when firing the motor up. It turned out that I had a new, yet defective ISV hose that was split somewhere in the middle (there was a seam), which I did not notice. The fact that you can hear it at the top of the motor tells me something is split under that intake, or a gasket may have slipped during the installation of the intake manifold.

I really would hate to tell you that the manifold may have to come off again. However, if it turns out not to be the FPR, that may be the case..

Dean_Fuller

Mark....pull the car outside and away from walls and concrete floor....maybe on the grass some where. The sound is bouncing off the walls...it will be MUCH easier to tell WHERE its coming from away from hard surfaces.

MarkRobinson

I did blow through the ISV hoses and even unplugged it to see if it was that, but yes I should check that again or replace them if I can. Wonder if my 'scope will pick up whistling in that area.

Mongo

I tell you, nothing is worse than hearing that sound after putting everything back together. It's a frustrating experience.

Leon Speed

I think it is the fuel pump.

LostInSpace

I had a leak between the throttle body shaft and bearing when doing my intake R&R - sounded very similar to this.

MarkRobinson

At the throttle plate shaft & end-bearing? I did not rebuild the TB, assumed it was ok as it was not mentioned as an issue when I received the parts. I did check/set the TPS & clean everything but that's it.

Mrmerlin

press the clutch pedal to the floor does the sound change?
Pull the dipstick drip the oil onto black cardboard,
look at the oil in the sun use a magnifying glass do you see metal?

remove the right side cam cover,
look for particulates on the belt.

maybe the oil pump gear is hitting the timing cover,

or the belt isnt running properly ,
or the thrust washers are not properly positioned

Imo000

Spray some starter fluid and see if the rpm goes up. If it does, concentrate on that area.

Lizard928

What happens when you rev the engine?

If it is fuel related the sound should be unaffected.
If it is vacuum related the noise will disappear.
If it is a bearing, etc. then the speed will increase and follow the RPMs.

Mrmerlin

IMO000....warning............ spraying flammable liquid onto the intake can cause an explosion if your ignition wires are leaking, then the flammable liquid will go boom

MarkRobinson

I've cut open the oil filter & looked, didn't see anything. I can look again. With raised RPM, the noise doesn't diminish much & returns as the RPM's stabilize. I'll check with the clutch pedal, it was on my list anyway.

I'll also listen to the fuel pump from under the car.