engine chirping

Check the serp belt. When it makes the noise, pour a little water on the belt to see if the noise stops. Make sure to protect your eyes and clothes from the water splashing back.

I have a 2000 old body style Tahoe Z71; 5.7 with the automatic tranny. Recently, there has been a "Chirping" noise coming from, what seems to be, the front of the vehicle. I took it to a local mechanic and he stated that the u-joints were bad. Replaced the u-jpints and the problem still exists. From a dead stop, if I give it reasonable gas pedal, it "chrips" 2-4 times (kind of sounds like a faint horn beeping) and goes away once I get rolling. If I SLOWLY accel from a dead stop I can keep it from making that noise; it does not make the noise while I am moving and give it gas. The tranny was serviced to see if it would cure the problem and it did not; the mech stated that there was good pressure in the tranny @ 20 psi. When this thing "chirps" it almost feels as if something is slightly slipping during the acceleration even though it is quick and hardly noticeable. Any ideas? Torque converter going bad? Good u-joints bad? Thanks!

it sounds like u joint issue to me. did he replace both u joints in the rear drive shaft? did he grease them? sometimes the new joints dont come with grease fittings and they could be dry.

[quote:6d503301e2="mastertechtim"]it sounds like u joint issue to me. did he replace both u joints in the rear drive shaft? did he grease them? sometimes the new joints dont come with grease fittings and they could be dry.[/quote:6d503301e2]

The tech replaced both rear shaft u-joints. I am taking it back tomorrow to have them look at it again. Quite possibly, he forgot to grease them.

also tell him to recheck the fluid level in the transfer case. a small amount of fluid leaks out when the drive shaft is removed and rarely is the transfer case topped off after the job is done and it is very important that the level is at the top.

[quote:554cdd7beb="mastertechtim"]also tell him to recheck the fluid level in the transfer case. a small amount of fluid leaks out when the drive shaft is removed and rarely is the transfer case topped off after the job is done and it is very important that the level is at the top.[/quote:554cdd7beb]

Great! Many thanks! What would be the recommended transfer case fluid for my model? Just to ensure he is correct in his offering. Weight? Type?

it takes regular dextron 3 transmission fluid. if it was my truck and you havent done yet. i would have him drain the transfer case and refill it completely. it only takes a few minutes and it will pay off for you in the long run. it will take about 3 quarts of trans fluid and take him about 10 minutes to do.

[quote:3fed1e2a9c="mastertechtim"]it takes regular dextron 3 transmission fluid. if it was my truck and you havent done yet. i would have him drain the transfer case and refill it completely. it only takes a few minutes and it will pay off for you in the long run. it will take about 3 quarts of trans fluid and take him about 10 minutes to do.[/quote:3fed1e2a9c]

Great! Thanks!

Check the flex plate to torque converter nuts, I've seen them drive people nuts!

Thinking about purchasing this 1999 Tahoe for my son. I've driven it about 70 miles so far, and there is this chirping sound in the front of the engine, but I am unable to narrow it down to a specific part. Serpentine belt appears to have been replaced, but I'm not sure if it is the problem. Noise gets a little louder with an RPM increase. Power steering fluid is good. Any ideas?

It may be a belt noise. You can give a quick blast of silicone or thin lube and it may stop it for a moment. Then if you take some valve grinding compound and smear it on both sides it will remove any glazing.
Cheap belts are more prone to noise.
A weak tensioner can add to a belt noise. Lastly a pulley may be the source. Try rocking each pulley to feel for any movement. Remove the belt and feel each pulley for any roughness.

Replaced the pulley on the tensioner, and about 85% of the chirping went away. Spun the idler pulley while the belt was off and I think it may be accounting for the only minor chirp left. Don't hear it now when the RPMs are up, only when it comes back down, and then only a little.

Spoke too soon, the noise is back. If the tensioner itself is weak it can cause this? Is that more likely than the idler pulley?

Original tensioner? good chance.

I have had multiple sources of it on my truck. Reasonable to expect wear on all the pullies and contributing, but a weak tensioner can be a source for sure.

Look closely at the tensioner mounting, IT the arm of the tensioner pulled in enough to see a gap that is unequal where it mounts?

Excellent addition to this thread! Please feel free to help out whenever you are on the site :)