MonteHall

I spend the weekend installing a new intake, and then re-tuning the carb, also I found that my exhaust manifold bolts had backed out, so I re-torqued them.
went for a drive today, got back and now this:


it louder from under the car.

BTW, it's an 84

Midnight 85

I had an El Camino with almost the same noise, chased it for 2 years until a guy told me something to try. Take a distributor gasket & cut it in half, loosen the dist. then lift it just enough to get the half gasket under one side. Tighten it down & start it up, if it is still there, move the gasket piece about 1/4 turn, repeat until it either stops or you have moved it all the way around the distributor. I know this sounds goofy but it worked for me. I am thinking the manifold may not be perfectly flat in the dist. surface which, when you tighten the dist. it ***** it slightly making that squeak or chirp whatever you want to call it. If this trick does not get it then I don't know what to say it might be.

MonteHall

I checked the dist plane with a mechanics rule, and didn't notice and deflection.
so I pulled my belt off and ran the car, noise is the same. so the only thing turning was the crank pulley, which is not touching the oil pan, I checked that by putting my hand behind it.

Using a length of hose as a stethoscope, I put it around the engine, it was noticeable in the drivers side valve cover, so I pulled that, then moved the hose around there as well, and it was extremely loud when I put the hose down the breather holes on the head.

Motor mounts physically looked OK.

cv67

Make sure it isnt coming from the flex plate area but honestly Id be taking a look at a rod bearing

envirotrans

when you put the hose in the breather hole was it the front or back of the head??
if it is fron the back the hight of the Distributor drive gear and cam my have changed

WVZR-1

It certainly should be easy enough to just lift and do a re-seat of the distributor. You would always start when diagnosing something to go back to the last major change and I'd say that's the last thing that you physically "tampered" with!

The suggestion with the distributor gasket is somewhat of a "legacy" fix but it certainly has in the past. It's been a very long time since I've heard it mentioned. I hadn't thought of my friend Chet for many years - pleasant memories. He'd mention something like that to you, scratch his head, wink and walk away! You sometimes wondered!

MonteHall

I pulled the distributor and reseated it with no change, i looked at the distributor gear and there is no new metal or anything that looks like its not right

envirotrans

The only thing that is left in there that was moved is the rod to the oil pump
.

WVZR-1

Why don't you just pick up a real stethoscope and go over it. A quality one is maybe $16 an inexpensive one $6. They're actually quite handy around the house, I'd get a better one!

envirotrans

If you have access to a different Distributor try it you may have broken something in it.

envirotrans

The only other thing i can think of is something fell into the valley before you put the intake back on.

jhammons01

I agree. Rather than trying to use your ears bare....

Just take a long metal rod and with one end to your ear, touch it to various parts of the motor, you'll soon isolate exactly where it is coming from.

Midnight 85

Very good possibility but I went all over my El Camino's engine with a stethoscope and it didn't show me a thing. If the noise is the same as mine was it is almost impossible to pinpoint and like the op's engine, the noise was louder under the car.
MonteHall, I had my distributor out a dozen times without finding this noise. I may be completely off as to my opinion of the noise but a distributor gasket is an awful cheap experiment.

fredd1

You might want to check your exhaust system. Tightening the manifold bolts might have disturbed something or reduced a clearance in the header, heat shield, brackets, etc.

WVZR-1

It might be worth investing in a distributor gear also. The only thing that he's changed is the manifold and it makes good sense that the relationship of the gear to the cam is certainly different. Maybe stack a couple gaskets and try it, see if it changes the pitch. What happens if you attempt to do the oil pump with a priming shaft?

MonteHall

I'm actually quite unable to get it running right with the new intake.
Tomorrow I'm going to put my old cast-iron intake back on and see what changes.

JackDidley

Sounds like a spun main bearing to me.

cv67

Rotating assy somewhere that poor thing is hurt.
Wish it were just a bad exhaust leak!

envirotrans

Now that I am home and have heard it sounds like a loose fan belt pulley, check and make sure the belt is centered on all the pulleys. and nothing has fallen behind one

lozer

Is it a 6 speed? and if so does it go away when you push the clutch in? Mine made the same noise till i tossed the dual mass flywheel. It would only make that noise when hot, it was exacerbated by the hot miss of my failing injectors and a black tag zf.

Sounded damn near just like that.