Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

1 - 7 of 7 Posts

·
Registered
2002 gmc envoy_sle
Joined
·
152 Posts
Discussion Starter #1
For a while now I've had no Envoy problems. Now I'm really confused. At startup the engine is noticeably louder - even the wife noticed it. I thought it might be the fan clutch but the RPM rate reads normal and no Check Engine Light. After warm up things quiet down - sometimes:duh:.

Manifold?
Exhaust gasket?

Or just cold weather (NY) related?
 

·
Registered
2002 olds bravada
Joined
·
2,369 Posts
What kind of noise is it? and what part of the engine do you think its coming from? does it get louder as the RPM increases?
 

·
Western Canada Chapter
2003
Joined
·
6,411 Posts
For a while now I've had no Envoy problems. Now I'm really confused. At startup the engine is noticeably louder - even the wife noticed it. I thought it might be the fan clutch but the RPM rate reads normal and no Check Engine Light. After warm up things quiet down - sometimes:duh:.

Manifold?
Exhaust gasket?

Or just cold weather (NY) related?
What's the mileage on the beast? R U running 5w-30 oil as prescribed in the manual?

Sometimes cold carbon knock will make your engine sound like it's gonna throw a rod when its cold. Maybe a Seafoam treatment is needed to clean out the combustion chamber? :m2:
 

·
Registered
2002 gmc envoy_sle
Joined
·
152 Posts
Discussion Starter #4
What kind of noise is it? and what part of the engine do you think its coming from? does it get louder as the RPM increases?

So far, I can't tell where exactly. Just under the hood. I realize I've got some detective work to do. Yes it does get louder as the RPM increases. Today should be a good test. I've got a bunch of local errands to run. I'm especially concerned because I'll be driving to NC (700 miles) next week.
 

·
Registered
2002 gmc envoy_sle
Joined
·
152 Posts
Discussion Starter #5
What's the mileage on the beast? R U running 5w-30 oil as prescribed in the manual?

Sometimes cold carbon knock will make your engine sound like it's gonna throw a rod when its cold. Maybe a Seafoam treatment is needed to clean out the combustion chamber? :m2:
Hi Bill,

Mileage is 60k and I do run 5w-30. I'll check the level today. Don't know about Seafoam, except when I take the Envoy out on the NC beaches:cool:
 

·
Registered
2003 chevy trailblazer_ls
Joined
·
5,267 Posts
During the cold weather season. engines just sound louder. the I6 engines for many of us tick louder too- usually because of the cold carbon knock.
But what you may be experiencing, especially if its pretty cold where youre at is that the fan clutch is staying locked ON- not because its failing. but because the oil in the fan clutch is cold and it moves slower... as the engine fan rotates- the thick oil will begin to distribute by centrifugal force and eventually it unlocks... and it quiets down.
We dont notice this much in warm weather beucase the oil is warm and flows much easier... as soon as it begins to spin- it gets distributed....
That may be what your noise is- just the fan spinning longer. this will not set error codes if its the slow cold oil in the clutch.
 

·
Registered
2002 gmc envoy_sle
Joined
·
152 Posts
Discussion Starter #7
Thanks RB. That may be all it is. Yesterday I took a few short trips and NO NOISE! Temps were in the 30's (10 degrees warmer than last weeks average).

So I'll consider the matter closed and change the oil when I get to NC.
 
1 - 7 of 7 Posts
Top