04 trailblazer LT weird engine noise

[IAFF78]

I have a 04 TB LT and noticed a weird noise coming from the enginecompartment. I recently replaced the spark plugs and cylinder 1 ignition coil. The video was recorded today and it was the 1st start up of the day plus it was around 15 degrees....if that matters. Any help would be greatly appreciated.

Thanks,
Kevin


04 Trailblazer engine noise: http://youtu.be/pOGMJEzWm8A

 

[Mooseman]

Your fan seems to have a lot of wobble. Try taking the belt off and start the engine and see if the noise goes away. If no more noise, then it's something belt driven so check each component.

Another question, does it do the noise only at idle or all engine speeds?

 

[BlazingTrails]

Sounds like the water pump to me......

 

[wehowardjr]

I posted that I have a similar problem but not as noisy and my fan doesn't wobble, and after the engine warms up the noise disappears. Once the truck is at operating temperature you can barely hear it running. The only give away is the slight exhaust rattle in the back.

 

[gmcman]

I believe the first topic was deleted because of a double thread but yes I agree it sounds like the water pump.

 

[wehowardjr]

It's still on here

http://gmtnation.com/forums/topic/12989-cold-start-up-noise/

 

[zephyr429]

Hi Kevin,
I have a 03 TB LT. Over the last few days I have been noticing an odd sound coming from the engine compartment and an odd vibration on hard acceleration. I commute 65 miles to Atlanta everyday so it kinda worried me. When I got in a few minutes ago I took a flash light out and it looked like my fan was wobbling. When I stopped the engine and manually tried to wiggle the fan, my entire water pump looked like it was moving a good 1/8-1/4 inch both ways. It sounds like we are having the same issue. Does yours move when the engine is not running?

Thanks,
Kevin (also)

** I just looked on rockauto and they have our water pumps for $25.79 $86.79 depending on the brand. Much cheaper than I thought. Hope this helps.

 

[IAFF78]

Kevin,

I gave the water pump a good wiggle when the motor was off and it seemed pretty solid. I did replace the serpentine belt yesterday but the noise is still there. Not sure what to check next.

Thanks,
Kevin

 

[BlazingTrails]

You have 2 tensioners that can be noisy, power steering fluid could be low, fan clutch could be going out, and just because your water pump has no play in it doesn't mean its not bad. You need a mechanic stethoscope.

 

[BrownHP800]

You say you replaced the belt, but did you run the truck without the belt and check for noise?

No belt, no noise then it is something belt driven. If the noise is still there it is more internal.

 

[Mooseman]

And with the belt off, you can more easily check for anything noisy. And to correct Blazingtrails, there is only one tensioner. There is however an idler that has a bearing that often fails, as well as a bearing in the wheel for the tensioner itself. With the belt off, you can spin stuff and and see if anything is going bad.

 

[Pete]

Sounds a lot like mine did when the waterpump gave out.

 

[Kurb]

Last week, I had a similar sound. It turned out to be the alternator. I luckily got a stethoscope for Christmas, and this was the first time I used it. With the stethoscope, I found that both the alternator and power steering pump were loud. I checked the power steering fluid and found the reservoir to be nearly empty, which helped me find the leaking power steering line that will be my next project. Adding power steering fluid fixed the power steering pump noise, but the loud noise was still there. The alternator voltage seemed fine, but it did change from 13.5-14 V while I was checking it. I pulled the belt off and turned all the pulleys by hand (except the crank of course). They were all pretty quiet and tight, but I felt drag on the alternator pulley when I turned it. I replaced the alternator, and the noise is gone.

 

[seanpooh]

Did you wiggle the water pump and fan when the belt was off? Having the belt on holds tension.
Also if you do go on buying a new water pump, make sure to buy a separate water pump gasket (AC Delco preferred).