View Full Version : Chirp w/ Hard Acceleration
hoezaycuervo
08-24-2006, 11:44 PM
I have an 02 LS w/ 88K on it. Recently I have noticed that under hard acceleration (approx 4K+ RPM) there is a chirp under the hood when the motor changes gears. It kind of reminds me of a turbo blow off valve sound...any ideas what it is and if I should take action to fix it? I think it might just be age...
Mine was starting to do that and became really bad after the converted plugged up, which caused the motor to un-rev even faster between shifts. Its most likely the serpentine belt has stretched to the point that the tensioner can no longer apply enough tension. (Replacement belts are around $25-$30 at the three stoodges and pretty easy to install).
ScarabEpic22
08-25-2006, 01:42 AM
OK, ylab, I had the same thing until I replaced my PS pump and serp belt, but it is still there, slightly.
What do you mean your converter plugged up, your catalytic converter or torque converter??
Im very interested as my TB is doing the same thing...
Boilermaker-744
08-25-2006, 02:59 AM
mine has done it from day one. I thought that it was normal.:confused:
MTPockets
08-25-2006, 06:40 AM
Yep, sure sounds like serp belt squeal. Some belts do it, some dont. If the belt looks good and all the pulleys & tensioner are good, all is well.
Joel
OK, ylab, I had the same thing until I replaced my PS pump and serp belt, but it is still there, slightly.
What do you mean your converter plugged up, your catalytic converter or torque converter??
Im very interested as my TB is doing the same thing...
My Catalytic plugged up and was replaced last month under the emissions warranty......they blamed the low mileage with lots of short trips as the reason. (32,000 miles on a nearly 5 year old truck). Engine had no low or top end, so it went gutless before the shift and the rpms would drop so fast that accessories had trouble keeping up and let out a howling squeal on the 1-2 shift. (It was only a light chirp on occasion beforehand). Replacing the belt took away all of the chirp & squeal. - Trust me, you'll know if the converter starts to plug up long before it shoots the PO420 error code.
Those belts do stretch quite a bit over time, mine had the tensioner just about at the limit of its spring travel. The new belt fit completely inside the old one when layed onthe ground without touching!
blandmiller
08-25-2006, 10:58 AM
I agree, serp belt. Check for glazing on both sides and replace if any area looks shiny.
04chevyMN
08-25-2006, 01:34 PM
this happens to alot of cars, its not a problem, its normal
TuneTimePerformance
08-27-2006, 02:48 PM
Serp belt but I would think at 88k you changed it once ? Ive had several gm's in the past that needed tensioners [ route of the problem they go faster when you bump up the shift mph] .
ScarabEpic22
08-27-2006, 04:22 PM
I definately noticed it was a lot harder to get the new belt on the engine and it was much tighter. Too bad I cant convince GM to give me a new cat, I would love to have the exhaust flange back!:D I had a really bad rotten egg smell for about a year and a half back in 03-04 and then I didnt drive the TB for a while, and now it hasnt come back.
TuneTimePerformance
08-27-2006, 05:22 PM
If you do the belt only I would bet 5-8k latter you will get the chirp back at wot. I've just had a lot of bad luck with them .LOL
ScarabEpic22
08-28-2006, 10:41 PM
Yeah, Im hoping it isnt the tensioner, but if it is I will replace it when the squeal starts again.