Need help locating squeal in engine bay UPDATED: THINK I FOUND THE SOURCE

If you can get hold of a really long screwdriver, put the truck up on stands, start it, crawl under there, put the screwdriver handle against your ear, and move the tip to various spots. Or get an automotive stethoscope and do the same thing. That might help you locate the source. You can also do a web search for "chassis ears." They let you place sensors at various spots and switch among them. I hate tracking down noises because they can often manifest "miles away" from their true sources.

 

Will a piece of aluminum round stock about 5/8" dia do the same or does the handle on the screw driver amplify the sound and make it easier to hear?

 

If that squeal is being caused from inside the motor and it is that apparent (loud) you have a big issue. It's probably the bearing on your crankshaft pulley. Did you spray it with a bit of wd40 while it was running? If the noise goes or away or gets quieter then you know what's causing it.

 

Yeah, that should work ok, but the screwdriver handle's rounded end seems to make for a better seal on my ear. You can test whatever you plan on using by holding it against something that's supposed to emit a bit of noise (valve cover, alternator, etc.).

EDIT: Might want to wrap a bit of electrical tape over the ear end to increase the diameter a bit and protect against the bar stock's sharp circumference.

 

I haven't done the WD40 yet. Help me understand how that would work. I have been looking at it seems like the crankshaft pulley doesn't have any bearing, it just slips on the keyed shaft and you tighten the bolt to keep it from coming off. From what I have looked at it seems that the seal could be bad but I really didn't notice any oil leaking but I will give it a better look when I get home. I don't think a bad seal would cause that sound.

Makes sense with the handle. Ill have to dig around and see if I cant find my long screw driver. If I cant find it ill put a bunch of tape around the end

 

Yup, anything long enough with a relatively small diameter will work. I've used pin punches, socket extensions, long screw drivers, a piece of rod stock. Like @c212 says, wrap a little tape to make it more comfortable. I find it works best to let it sit on the tragus. That's your word of the day. That's the term for that not quite bone, not quite soft cartilage flap sort of thing covering your hearing hole. A long handled screwdriver with a ball end sits on that just perfect and the sound is very clear.

 

If you've taken off the accessory serpentine belt and find you can still isolate the noise to the front of the engine here's what would be still turning. The oil pump and camshafts are behind the timing cover and driven directly or with gears and chains. But the typical bearing noise sources, idlers, water pump, alternator, steering pump, A/C compressor should be eliminated without the belt. I still hold out finger's crossed it's throw out bearing noise though.

 

I'm wondering if anyone has suggested a bad fan clutch?

To confirm the diagnosis, start with this simple test: Spin the fan as hard as you can on an engine that has not been started that day. If the fan rotates freely, you can bet the clutch is bad. You should feel some resistance and the fan, depending on the ambient temperature.

Does the sequel change if your move the steering wheel one way to the other (thought it might be a power steering pump)? If you hear a whining noise while turning the wheel of your vehicle, something is wrong with your power steering system

Good Luck and keep us posted!

 

He ran the engine with the serpentine belt off so that eliminates PS pump, water pump, fan clutch since they weren't driven or spinning at all.

 

Started the truck up to see if I could locate a general area of where the noise was coming from and as luck would have it, it’s not squealing right now. I let it run for about 5 mins to see if it would start talking to me. In the mean time I stuck the alum rod on different parts of the motor to see what I could hear and get an idea so when it does start squealing I’ll hopefully be able to pin point the noise.

Going to let it sit for a few mins while I do a few other things and give it another go and see if it will start squealing

 

Also got under the truck and checked for an oil leak and everything is dry

 

Started the truck up again and let it idle for 10 mins or so. Never would squeal. Got in the truck and pushed the clutch in to move it and the squeal started back. This time I slowly pressed the clutch back in and could tell a slight difference in the pitch of the squeal. I’m pretty sure it’s the throw out bearing even though it was replaced about 12,000 miles ago.

With that said, A big Thank You to all that gave your suggestions of things to check and how to check them. Now to figure out about getting the throw out bearing fixed. I remember seeing a thread about a fix for it.

Thanks again everyone. When I can get this fixed I will update

 

There's an inspection plate on the driver's side of the transmission, 3 bolts and you can see inside the bell housing and see the clutch and release bearing. If all that was done was to replace it there's a good chance the snout of the transmission has worn a groove which hangs up the operation of the bearing. When I did the clutch in my truck I had to sleeve the snout and use a special bearing machined slightly larger to fit over it.

This is the company I got it from: http://www.pdmusa.com

 

I will have to check that out. It will be Sunday before I have a chance to get back under there and look. When I bought the truck from a used car dealer that only deals with toyotas, he had the throw out bearing and clutch replaced. At least that's what he told me. I do know that the squeak from the throw out bearing that was there when I originally looked at it wasn't there when I went back and ended up buying it. I didn't think it would go out that quick so I automatically ruled that out with out really investigating it.