Squeal Under Acceleration

[Montync]

Hello all, I have 1986 C10 with a 305. I have about 1000 mile on a rebuilt engine. I have a squeal under acceleration(Just started). I have removed all the belts, and checked all vacuum leaks with smoke. I replaced the u joints as a last ditch effort and still no luck. I did notice intermittent water vapor puffs out of the exhaust only on one side under load(wheels chalked and truck in drive) when checking the u joints.
During the rebuild I torqued the head bolts in the proper sequence 3 times, each time letting it sit overnight. I did Not re-torque the bolts after the initial break-in. So here are my questions:

Will a improperly sealed head gasket cause the squeal?
Should I have re-torqued the heads after break-in?
What should be my next step, re-torque the bolts?

Thanks

[old Rusty C10]

Im not sure if you should have waited to retroque the bolts each time overnight... Iv e never waited longer than the time it took me to finish torqueing the prior sequence

[Montync]

Thats what worries me. Some forums I looked over said to re-torque and let it sit overnight others said not to.

I used new bolts and the first time I re-torqued them after sitting overnight it sill gave about 10 degrees worth of turn before clicking (New snap-on torque wrench brought down to zero after each use). The second time maybe 2 degrees, and the last time it just clicked no movement. I am wondering with new bolts I should have re-torqued them after break-in. My intake went through the same torque sequence and after about 500 miles were so loose you could unscrew them by hand, I torqued them hot, and then the next day re-torqued them cold and they have not budged since.

[LONGHAIR]

It wouldn't cause a squeal, but I would be concerned about that torque procedure....mostly for the thread sealer. Letting it sit so long between torque changes could break that seal.
I have never waited any longer than it takes to readjust the torque wrench.
"Three times" is not very specific.....does that mean "in increments" up to the final torque value? or triple-checking that final value?
I am going to assume that by stating the "10 degree movement" and then the "no movement" that the latter is the case?
As far as that goes, "re-torquing" is more about the gasket itself than it is about the actual procedure. Modern composite gaskets should no require re-torquing once they are properly done in the first place.

As a side note...You can never actually "check" the actual torque of a tightened bolt. It takes more initial force to get the bolt moving than the amount of torque it took to get it there. So if a bolt was torqued to 60 ft-lbs, it might take as much as 70 ft-lbs before the bolt would move before "clicking". The amount of torque needed will vary based upon several factors, including lubrication.

[superwade57]

Not to be a smarty pants but my 73 has a squealing under acceleration too. But by design .

How strong of a motor is this? What specs? I know its a 305 but exploring options .Are you running v belts or serp? I'd say if its v belt and a stout motor maybe you are spinning the belt or slipping it?

[donut]

You ruled out the belts, usually that's the problem. Could the squeal be related to the flexing fuel pump? or was that someone else?

Water vapor puffs, unless it's real heavy, usually not a concern. The temp did drop 20* from yesterday.

[Montync]

The bolts used were felpro, I followed the Haynes rebuild procedure, but its so vague that i got concerned and followed searches on forum rebuilds, most searches said to let it sit overnight then re-torque. I always triple check, but would the Teflon tape rip so much it would leak? As far as the fuel pump bolt I can see that if its loose at idle it would not squeal maybe, under acceleration the force might cause it but, why only under load?

As far as the head bolts, (cheap...I know I know) but should I reseal the threads (Teflon or fuel, oil, coolant proof sealant) in order or buy new bolts and replace them one buy one in order at the proper specs.

also with the 1094 felpro head gaskets should the torque be increased?

I might have just screwed the pooch, it was my first rebuild if that helps!

[Montync]

When it is freezing cold it will not squeal until it reaches temp 160 degrees... usually 5 miles... if its warm 50-60 it will not squeal until about 2 miles at the same 160 mark... as far as the vapor it is coolant, the muffler stops at the axles and there is water/coolant buildup and it is a sweet waffle cone smell.

[Montync]

Keep in mind true duels!

Ok just went outside and let it run, 33 degrees outside...... without it warming up to 160...put it in drive (load) and no vapor (dark outside with flashlight). put it in neutral, got up to to about 90 (no vapor) drove it around the block. Parked it checked no smoke/vapor... Let it sit in Neutral... got it up to 160....(bam vapor rolling as if I were in a cigar shop only on the passenger side)... poped the hood releases the pressure on the radiator cap (emergency pressure release caps) checked for vapor but not as much!

[LONGHAIR]

First of all....set fire to whatever book told you to use teflon tape on head bolts, and anything else by the same author for that matter.
There are several brands of liquid thread sealers made just for that.
The Felpro gaskets are fine as are stock type head bolts. These earlier engines do not use "torque-to-yield" bolts, so they can be re-used, though I wouldn't do it more then a couple of times or on a really hi-performance engine.

I would guess that you have some kind of steam related issue, but I really don't know how it could make a noise that you could hear? Air pocket trapped in the head? That could make it run hot, but shouldn't make noise.

Exhaust leak?

[king-918]

Originally Posted by Montync

The bolts used were felpro, I followed the Haynes rebuild procedure, but its so vague that i got concerned and followed searches on forum rebuilds, most searches said to let it sit overnight then re-torque. I always triple check, but would the Teflon tape rip so much it would leak? As far as the fuel pump bolt I can see that if its loose at idle it would not squeal maybe, under acceleration the force might cause it but, why only under load?

As far as the head bolts, (cheap...I know I know) but should I reseal the threads (Teflon or fuel, oil, coolant proof sealant) in order or buy new bolts and replace them one buy one in order at the proper specs.

also with the 1094 felpro head gaskets should the torque be increased?

I might have just screwed the pooch, it was my first rebuild if that helps!

Unless you are working on something exotic that ive never seen, there's no reason to not finish torquing a head in one sit down. You should have put oil on just the threads of the bolt to insure proper/even torque. If you use anything else you have already made a mistake. Check for bearing noise

[LONGHAIR]

Originally Posted by king-918

You should have put oil on just the threads of the bolt to insure proper/even torque. If you use anything else you have already made a mistake. Check for bearing noise

This is absolutely not right! Many of the bolt holes in the block are open to the water-jackets around the cylinders. If you don't use a thread sealer, you WILL have a leak....around every one of them.
I found this out "the hard way" more than 30 years ago, when rebuilding my first 350. Everything I read at the time gave torque specs for "lightly oiled" threads and said nothing about the sealer on the head bolts. I don't know whether it was just an over-site or they expected readers to know this?
Big mistake, cost me several hours to backtrack and repair...

[king-918]

Originally Posted by LONGHAIR

This is absolutely not right! Many of the bolt holes in the block are open to the water-jackets around the cylinders. If you don't use a thread sealer, you WILL have a leak....around every one of them.
I found this out "the hard way" more than 30 years ago, when rebuilding my first 350. Everything I read at the time gave torque specs for "lightly oiled" threads and said nothing about the sealer on the head bolts. I don't know whether it was just an over-site or they expected readers to know this?
Big mistake, cost me several hours to backtrack and repair...

Corrected sealant for old bolts, arp if I remember right has has some already on the bolt

[LynnJr]

To the Original Poster.
I use sealer on studs and motor oil on bolts and never have a leakage problem.
You mentioned the motor squeals when hot and puffs out of one side plus that the manifold bolts were loose.
I suspect you have sucked a intake gasket on the side puffing and the squeal is from a vacuum leak on that same side.The intake gasket probably took a set after a small amount of running time and when you re-torqued it it was probably already leaking.
When the motor heats up you build pressure inside the radiator and the water is forced into the combustion chamber through an intake port.

I don't know how hard that motor is to work on but I would pull all 4 plugs on the side that is puffing steam.You are looking for one plug that looks brand new and unused.The others should look used.

If you find one that looks like new its time to replace the intake gasket.

[tucsonjwt]

If you had not said you removed all of the belts, that would have been my first guess. Maybe you are looking too deep - could it be something like a pulley - crank or water pump? I had a bolt work loose on the crank pulley of my 454 and eventually all 3 bolts worked loose and the pulley eventually fell off - I have no idea what caused this, after 10 years of driving it and no engine work. The sound was a high pitched metallic "squeal", but not quite a a belt sound.

[king-918]

How about a video?

[Montync]

Head bolts were loose, no more vapor. Squeal is still there. will rotted control arm bushings cause a squeal under acceleration?

[Rnd]

Originally Posted by Montync

Head bolts were loose, no more vapor. Squeal is still there. will rotted control arm bushings cause a squeal under acceleration?

"During the rebuild I torqued the head bolts in the proper sequence 3 times, "???

[Sodell]

Remember this was the guys first build, and it sounds like he did it with no one's help. Keep at it Monty, you'll get it. If it's not the belts, it could be your bearings. Did you gauge them when you put it back together?

Is it louder or a different pitch when accelerating?

[Montync]

I did plasti guge them. They were within spec. The squeal is consistent in tone but gets louder when the gas pedal is pressed. If I let off the gas the sound goes away.

[Montync]

Ok so in an attempt to get a video of the squeal posted my exhaust drowns out the sound. I tried recording on top of the engine, below, beside the truck, and at the exhaust, no sequel.

So here is more information, If I have someone hold the brake with the truck in drive,rev the engine and I stand next to the motor, you cannot hear the squeal.

Same situation but lying next to where the transmission is (Of course to the side) The squeal is heard lightly

If I stand behind the truck near the exhaust outlets Is sound like someone is killing a spider money that is clawing its way off of a chalk board at 100 mph. (This is the same sound I hear on acceleration).

All exhaust hangers were padded with wet pieces of t shirt. The squeal remained.

Exhaust setup: 11500flt long tube headers, headman header extensions, fake catalytic converter, stock intermediate pipe, and thrush welded mufflers.

what would cause a squealing/screeching exhaust?

[Houston Ben]

I don't know if this will help or not but I once had a problem where by tranny bolts loosened up and my torque converter started rubbing somewhere on the tranny making a squealing/screeching noise till I tightened them back down.