Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 11 of 11 Posts

·
Registered
2002 gmc envoy_slt
Joined
·
4 Posts
Discussion Starter · #1 ·
Whats up everyone. Hoping someone can point me in the right direction with this issue.

Its a 02 Envoy with the I6 and about 144k.

With the truck in park at idle, if you tap the gas pedal, the rpm's drop to about 300, the motor stumbles a little, then it revs up and falls back to idle.

Hasnt stalled, but seems really close to it.

Have another issue going on, not sure if they are related. Thinking the exhaust manifold is leaking. took the heatshield off to take a look, and didnt see any cracks or holes or soot, but it really sounds like an exhaust leak on the passenger side front of the motor.

Started as a ticking noise, so we took it to the dealer to diagnose, they said the water pump and fan clutch were making the noise, so i replaced them on my own. But still has a little tick and what sounds like an exhaust leak.

Just need a little direction. I can replace parts no problem, but suck at diagnosing what the issue is.

Thanks for any input.
Andy
 

·
Banned
2003 gmc envoy_slt
Joined
·
7,190 Posts
:tiphat Welcome :tiphat .The falling idle does sound like a dirty t-body: http://forums.trailvoy.com/showthread.php?t=51619 . There have been reports of exhaust manifold studs breaking. Does the sound go away when the engine heats up? That would point to a cracked manifold. As the metal expands the crack closes-up.
 

·
Registered
2002 gmc envoy_slt
Joined
·
4 Posts
Discussion Starter · #5 ·
Ill try cleaning the TB and see if that helps the problem.

The exhaust leak is consistant. sounds the same when cold and warm. And increases in volume with enging speed.

Thanks for the info, anything else i should take a peek at while im at it?
 

·
Registered
2002 olds bravada
Joined
·
2,369 Posts
I'm having that problem too. I have changed/cleaned everything i could think of. Now i'm starting to think fuel pump going bad because it makes a funny noise..
 

·
Registered
2002 gmc envoy_slt
Joined
·
286 Posts
I am not sure if this is applicable to the envoy/TB but on other cars this has been a dirty throttle position sensor.
ALSO I have noticed this from broken vacuum hoses aka vacuum leak.
 

·
Registered
2002 chevy trailblazer_ltz
Joined
·
9 Posts
hey andyandchristie,

I stumbled on your exhaust problem trying to solve another problem, I had the same problem with my 02' trailblazer last summer, constant noise, got worse when you gave it gas, etc, took it to a muffler shop and they told me that it sounded like the exhaust manifold gasket had broken or something along those lines, they said would be about $300, they went to go fix it and found out that the manifold was just loose, easy fix. good luck
 

·
Registered
Joined
·
5 Posts
I had a similar issue with my 02' Trailblazer and changing the fuel filter fixed it. That was one of many possible solutions and it was the cheapest and easiest so I tried it first... Luckily it worked.
 

·
Registered
2002 gmc envoy_slt
Joined
·
1,282 Posts
My 2002 Envoy has done this since new. I know have 119,000 miles on it, it still does it I have no DTC's. I clean my throttle body inside and out every oil change (5,000 miles). Its been discussed here before and was deemed to be part of the "nature of the beast" :m2:
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
63 Posts
Whats up everyone. Hoping someone can point me in the right direction with this issue.

Its a 02 Envoy with the I6 and about 144k.

With the truck in park at idle, if you tap the gas pedal, the rpm's drop to about 300, the motor stumbles a little, then it revs up and falls back to idle.

Hasnt stalled, but seems really close to it.

Have another issue going on, not sure if they are related. Thinking the exhaust manifold is leaking. took the heatshield off to take a look, and didnt see any cracks or holes or soot, but it really sounds like an exhaust leak on the passenger side front of the motor.

Started as a ticking noise, so we took it to the dealer to diagnose, they said the water pump and fan clutch were making the noise, so i replaced them on my own. But still has a little tick and what sounds like an exhaust leak.

Just need a little direction. I can replace parts no problem, but suck at diagnosing what the issue is.

Thanks for any input.
Andy
Well the idle problem you mentioned above when tapping the accelerator slightly was solved on my part when I changed out my battery to a better one, in fact everything idled smoother. Thaks to a post somehwere deep in this site :)
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top