Very Strange Noise.. HELP!

[markdoddridge]

I have an 04 H2, and the engine is making the worlds strangest noise. Its not a ticking, or a rapping, its like something got loose and is bouncing around inside the engine compartment.

Its only present at idle and slow speeds. Once i speed up it goes away. Also when i rev the engine it doesnt get louder. Its almost like a screw or a bolt fell out and is rattling around somewhere.

If anyone has ever had a quarter get loose inside their dryer, it sounds almost exactly like that, but faster

Anyone had anything similar to this? the check engine light is also on

[LoJac963]

best bet would to get the truck scanned and see what the code is that's beging thrown.

[markdoddridge]

best bet would to get the truck scanned and see what the code is that's beging thrown.

Roger that, ill take it to the dealership tomorrow

thanks!

[LoJac963]

O-reilly or auto zone will scan it for free, not sure if the dealer charges anything or not. I know auto zone will even give you a small receipt printout of all the codes.

[[__--MUD--__]]

thats odd...First place I'd start looking is around the fan shroud. But your check engine light and only hearing it at low rpm I'd be looking at the valve train also.

W/ the truck in park at idle or low rpm, does it still make the noise?

[markdoddridge]

']thats odd...First place I'd start looking is around the fan shroud. But your check engine light and only hearing it at low rpm I'd be looking at the valve train also.

W/ the truck in park at idle or low rpm, does it still make the noise?

Yes, at idle in park and at low rpm it makes the noise, hopfully its not something terible wrong. I had no idea autozone would scan it for free, im definatley gonna do that.

What do i do with the code once i get it?

[[__--MUD--__]]

So its definately in the motor if it does it in park...nothing in the engine bay that moves or can jump around while not moving.

I'd lay $5 your check engine like is probably a knock sensor getting tripped from the rattling the engine is making.

Do you know the broom handle stethoscope trick? I use the kind you can inscrew from the broom head and stick the end straight in your ear.

http://3.bp.blogspot.com/_ttYBeZtXmBU/THaLk1_v-QI/AAAAAAAAAhI/yYNPKdBU1yE/s400/broom.jpg

You can pinpoint engine noises that way. I wouldn't drive that mother ****er if I were you untill you figure out where the noise is coming from, trashed motor wouldn't be fun. I'd start by the base of the intake where it meets the heads. The next thing I'm pointing at is a lifter, push rod or rocker. Those will make a hell of a racket at low rpm if any of them came unglued. Start hunting around w/ the broom handle, it wont cost you anything. Just make sure you dont jam the end in the serpentine belt while its running. I've seen that happen before. Good luck!

[markdoddridge]

']So its definately in the motor if it does it in park...nothing in the engine bay that moves or can jump around while not moving.

I'd lay $5 your check engine like is probably a knock sensor getting tripped from the rattling the engine is making.

Do you know the broom handle stethoscope trick? I use the kind you can inscrew from the broom head and stick the end straight in your ear.

http://3.bp.blogspot.com/_ttYBeZtXmBU/THaLk1_v-QI/AAAAAAAAAhI/yYNPKdBU1yE/s400/broom.jpg

You can pinpoint engine noises that way. I wouldn't drive that mother ****er if I were you untill you figure out where the noise is coming from, trashed motor wouldn't be fun. I'd start by the base of the intake where it meets the heads. The next thing I'm pointing at is a lifter, push rod or rocker. Those will make a hell of a racket at low rpm if any of them came unglued. Start hunting around w/ the broom handle, it wont cost you anything. Just make sure you dont jam the end in the serpentine belt while its running. I've seen that happen before. Good luck!

Wow thats awesome, thanks!

[markdoddridge]

Ok so i just took it into the dealership, they say its the catalytic converter that needs to be replaced at $800. also they need to clean the fuel lines ($300) or it will mess up the new converter, and they reccomend a tune up ($700) which changes out the spark plugs and wires etc..

I told him to hold off on the repairs until i can do some research. Does this sound legit? im worried it was just the bolts on the intake manifold that came loose and they are going to charge me for all these unnecessary repairs

[H2005]

I would get a second opinion the stealerships are usually out to **** you over

[giant h2]

Ok so i just took it into the dealership, they say its the catalytic converter that needs to be replaced at $800. also they need to clean the fuel lines ($300) or it will mess up the new converter, and they reccomend a tune up ($700) which changes out the spark plugs and wires etc..

I told him to hold off on the repairs until i can do some research. Does this sound legit? im worried it was just the bolts on the intake manifold that came loose and they are going to charge me for all these unnecessary repairs
dirty fuel lines? how does that Jack a converter?

[markdoddridge]

dirty fuel lines? how does that Jack a converter?

And why do both need to be replaced? seriously questioning this now....

[HummerMann]

It sounds to me like it could be the cat O2 sensor giving you the check engine light. Unless someone ran leaded fuel in your engine to cook your cat, I'd be very leery of replacing the cat. The fuel line cleaning makes no sense at all to me - that's why I hate stealerships. They told me on a BMW I had 15 years ago the clicking noise at idle only was my injectors and they wanted $1500 to clean them. It turns out the Peake codes were for the VANOS circuit board and I fixed it myself for 130. It was the last dealing I ever had with that dealeship and BMWs, and I REALLY miss my old Hummer dealership here which had the best mechanics I ever dealt with.I would definitely get a second opinion.

[[__--MUD--__]]

well this just jogged my memory.... There is a crappy shield between the cat and the floor pan. It can rattle making an odd noise. The fix is a big ass band clamp if I remember correctly.

Seriously, use that broom handle and you will find where the noise is coming from.

Those plugs are good for 100,000 Miles. I sure as **** wouldn't pay someone $700 to swap plugs and wires. There isn't even a distributor on these motors. Individual coils are right over each cylinder.

[markdoddridge]

']well this just jogged my memory.... There is a crappy shield between the cat and the floor pan. It can rattle making an odd noise. The fix is a big ass band clamp if I remember correctly.

Seriously, use that broom handle and you will find where the noise is coming from.

Those plugs are good for 100,000 Miles. I sure as **** wouldn't pay someone $700 to swap plugs and wires. There isn't even a distributor on these motors. Individual coils are right over each cylinder.

I just called the dealership to get my truck back so i can get a second opinion. They are saying its not driveable.... im worried if i put my foot down the mechanic will screw it up on purpose to prove me wrong..

I tried the broom method but i dont really know enough about engines to know what im doing, and i couldnt locate where the sound was coming from. I want to try it again before i shell out the money but i dont want the mechanic to break my engine to prove me wrong

[cecil-1]

So a plugged cat, dirty fuel lines and bad plug wires make it not driveable? Thats crazy. Ya drove it in right? I think ya might want to go get it from em as soon as possible. Dont call... Just show up and tell em ya want it back. and try to keep an eye on it so they dont F*** with it.

[markdoddridge]

So a plugged cat, dirty fuel lines and bad plug wires make it not driveable? Thats crazy. Ya drove it in right? I think ya might want to go get it from em as soon as possible. Dont call... Just show up and tell em ya want it back. and try to keep an eye on it so they dont F*** with it.

Thats the plan, ill report back after lunch

[markdoddridge]

Ok, i got my car back. I ambushed them on my lunch break and just showed up asking for my car back. She said she couldnt release it, its a safety issue. I demanded they return my property to me, she said they could give me a ride home, when i still wouldnt budge she offered to get me a rental car for the day (i had told her i needed the car for the night).

After a bit more arguing i got my car back. I found a shop through a friend and im taking it there tonight.

I dont think the dealership screwed up my car, it sounds the same as when i dropped it off.

[Easy Ed]

Also, had the shield on my muffler fixed under warranty with new shield and those big a$$ hose clamps. It would make a rattling sound at idle and just off idle. I found it by taking a rubber mallet and beat on the exhaust pipe making it recreate the problem. The spot welds that held the sheild on broke loose from the heating up and cooling down. Could only hope that is your problem. :o

']well this just jogged my memory.... There is a crappy shield between the cat and the floor pan. It can rattle making an odd noise. The fix is a big ass band clamp if I remember correctly.

[markdoddridge]

Update: after fighting tooth and nail to get my truck back from the dealership (They said they couldnt release it, its unsafe to drive) i took it to Titan Automotive.

Their second opinion was practically the same as the dealerships, one of the CATs is coming apart and causing the noise. They quoted me the same price as the dealership, but arent pushing a $300 fuel line flushing, so im going to go with them.

I feel like i can trust the dealership more now, it makes sense that if dirty fuel caused the CAT to break then fixing the problem is a reasonable reccomendation

[cecil-1]

markdoddridge do ya know if its the cat coming apart? or is it just the heat shield rattling on the cat? If its just the shield rattling on the cat that is usually an easy fix with a band clamp.No need to replace. if the cat is coming apart itself it does need replacing. Would be alot cheaper just gettin a band clamp or two and some seafoam to clean the fuel system.

ETA im no mechanic but with those issues i just dont see how this vehicle would be considered unsafe. im sure someone with much better knowledge of hummers than me will chime in soon enough.

[Humdingah]

What month in 2004 did the truck go 'In Service'? GM has an 8 year/80,000 mile warranty for the catalytic converter but "the applicable warranty period shall begin on the date the vehicle is delivered to the first retail purchaser..."

So you may be able to, based upon mileage and in-service date, get it replaced under warranty.

http://www.justanswer.com/uploads/mcvgreg/2008-04-20_165903_2004-Trailblazer-Emission-Control-Warranty.pdf

[markdoddridge]

What month in 2004 did the truck go 'In Service'? GM has an 8 year/80,000 mile warranty for the catalytic converter but "the applicable warranty period shall begin on the date the vehicle is delivered to the first retail purchaser..."

So you may be able to, based upon mileage and in-service date, get it replaced under warranty.

http://www.justanswer.com/uploads/mcvgreg/2008-04-20_165903_2004-Trailblazer-Emission-Control-Warranty.pdf

Thanks guys, but my truck has 90k miles already. Both the dealership and Titan said the cat needed to be replaced so im inclined to believe them. Although its possible a clamp could have fixed this, if i knew more about engines i could have probably found out for myself