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2004 chevy trailblazer_ls
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2 Posts
Discussion Starter #1
Just a little post to let some folks know that a nasty rough idle and noisy acceleration (especially 1-2 upshift) in my 2004 Trailblazer was actually caused by a faulty water pump!!?!. I never lost any anti-freeze, but could always smell it, I only noticed a rough bouncy idle, not RPM's bouncing, but the passenger compartment would actually bounce a bit at stoplights and such. Idle noise was maybe a bit louder than usual, but the noise on hard acceleration was unbelievable. Kinda sounded like ball bearings rattling around an empty coffee can, but not as metallic, maybe a plastic coffee can, really bad on the 1-2 upshift, and still there but not as noticeable in 2-3 upshift.

I checked and replaced all kinds of things related to rough idle, cleaned out the throttle body, replaced sensors, and never once noticed the wobble and shake from the water pump.

Only when I got to looking into the motor mounts as a source of vibrations and shake did I notice the play in the water pump. The bearings were gone, shot, kaput.

New pump installed, and the difference is incredible, nice smooth idle, no more rattling apart on acceleration, fixed.:woohoo:

I would have never guessed that a water pump would cause such issues, especially never leaking any antifreeze, and never overheating the engine.:weird:

Just in case someone else is having a similar issue........
 

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Registered
2006 chevy trailblazer_ls
Joined
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2 Posts
Just a little post to let some folks know that a nasty rough idle and noisy acceleration (especially 1-2 upshift) in my 2004 Trailblazer was actually caused by a faulty water pump!!?!. I never lost any anti-freeze, but could always smell it, I only noticed a rough bouncy idle, not RPM's bouncing, but the passenger compartment would actually bounce a bit at stoplights and such. Idle noise was maybe a bit louder than usual, but the noise on hard acceleration was unbelievable. Kinda sounded like ball bearings rattling around an empty coffee can, but not as metallic, maybe a plastic coffee can, really bad on the 1-2 upshift, and still there but not as noticeable in 2-3 upshift.

I checked and replaced all kinds of things related to rough idle, cleaned out the throttle body, replaced sensors, and never once noticed the wobble and shake from the water pump.

Only when I got to looking into the motor mounts as a source of vibrations and shake did I notice the play in the water pump. The bearings were gone, shot, kaput.

New pump installed, and the difference is incredible, nice smooth idle, no more rattling apart on acceleration, fixed.:woohoo:

I would have never guessed that a water pump would cause such issues, especially never leaking any antifreeze, and never overheating the engine.:weird:

Just in case someone else is having a similar issue........
I have these exact same symptoms. Started out of nowhere yesterday. Only difference, my trailblazer is dying when I stop at a stop light. Was yours dying with this problem?
 

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Registered
2002 gmc envoy_slt
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4 Posts
My envoy died at lights for a while I checked a known cause the pressure switch located under the car next oil filter housing they get old and leak small amounts of oil and set off the engine light and says oil pressure low. I took a can of brake parts cleaner to mine cleaned the gunk off haven't had an issue yet but I do plan to change it . In time.. hope that helps tho
 
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