exhaust rattle

wowens · March 24, 2003

I have an exhaust rattle that occurs with a light load on the engine. You can't hear it with no load, or if you give it a little more gas. You hear it mainly right as you are getting back on the gas. I've had it to the dealer twice and it goes away for about a week then comes back.

Anyone seen this or have a suggestion. It is a stock 2002 1500hd 6.0l

Thanks for you help

jth7186 · March 25, 2003

I think I know what you're talking about -- but mine is on an 03 1500 4x4 with the 5.3 engine. Same symptoms though: usually noticed while unloaded and travelling in overdrive at around 40 mph (around 1100 RPMs). I think it is exhaust rattle due to the very low RPMs in overdrive when the problem is noticed.

I have found it usually when reapplying the accelerator coming up a hill, and it is only momentary. Once the truck shifts into a lower gear (or the RPMs otherwise come up above 13 or 1400), the problems goes away.

SilveradoWV · March 25, 2003

I have the rattle also, I think they can re program the tranny to shift sooner or something and it eliminates it, if this is the same thing you are talking about. Mine mostly went away when I went from 245's to 265's. I guess that effected stuff all through the driveline?

The Beav · March 26, 2003

Count me in as a 'club' member. Same rattle @ 1100 rpms on an '01 Z71 5.3L. I just recently put on new tires (Michelin 10 ply) and thought that might be the cause, pushing more weight.

siskiyou · March 26, 2003

I had an exhaust rattle also. Started after towing my Travel Trailer about 500 miles at 105 degrees. I took it to the dealer and they found the cover on the bottom of the muffler was loose. These are held on by a clamp that is crimped on and they said Chevy didn't have a fix for it. Anyway, they got a very long hose clamp and wrapped it around the muffler and the heat shield and it has been quiet since. That was about 5000 miles ago.

nhkid28 · March 26, 2003

I would have thought that would have fixed the problem by now. I have it too. At 36k miles I switched over to Mobil 1 atf and added Lubegard Red, this has quieted it down a some but it is still there. I have been to dealership after dealership with this problem and have all of the latest tcm updates, with no satisfaction. I have complained to Gm customer service and they said that they will note this in my file.

I could fix this my self if I could some how raise the speed when the tranny shifts into overdrive in 4th gear from 37ish to about 45 mph. Until then its either drive in D3 or live with the noise.

Also this is a torque converter noise not an exhaust rattle. Next time it does it just feather the brake while your foot is on the gas and the noise will stop. It will also downshift out of overdrive.

jth7186 · March 27, 2003

Darn. Good info, but one would sure think GM could come up with something better than a hose clamp and a quizical look...

Does anyone else know of a simple fix? This darn sound sure is annoying.

jth7186 · April 30, 2003

I took my "exhaust rattle" to the dealer yesterday to have them check it out. Took the shop foreman (nice guy, really) for a ride to duplicate the noise and, once he heard the noise, he looks at me with a concerned look and says, "it is nothing detrimental."

Nonetheless, they couldn't figure out the noise. Today, I took it back in so they could spend a little more time with my 1-month-old, 2800-mile-new Silverado.

Late this afternoon, I was informed that the noise was tracked and isolated to my transfer case and that the transmission was completely disassembled on the shop floor.

No, I didn't get a rental car. They apparently forgot about me sitting at my office after they told me a rental car was forthcoming.

I sure hope they figure out the problem, otherwise this will be nothing more than an exercise in "how to waste time and tick the customer off."

Hmmm.

Shaners · April 30, 2003

I had my '00 Silverado reprogrammed at the dealer to eliminate the "drone" in the driveline from going into OD too soon. After the reprogram, the torque converter didn't lock up until about 45 mph.

I think GM has since discouraged dealers from doing this because it supposedly affects fuel milage.

The only other suggestion I would have is to drive in "3" until you get on the open road and then pull the gear selector into "D".

DJFZ71 · May 1, 2003

I had a rattle when first started it up in the morning and once it warmed up it would not be as noticable. I got under one day and thought it was the heat shield. A month ago when a got the oil changed I had the dealer look at it. It ended up being something with the o2 sensors. Got both replaced under warranty. Rattle gone!

gnet158 · May 1, 2003

I have the rattle too. I've heard other Chevy/GMC 1500 do it to so I'm not concerned. I'm in the process of getting a "Dealer needs to fix" list but I only have 2 minor items on it. The only thing that worries me about taking her in is my air intake system. When they see it will they log it into the computer so that all dealership will know? Because if they try to blame that I will take it off and put back my stock air box.

ClipperSkipper · May 2, 2003

My truck rattles as well, on the first start in the morning,

usually clears up by the time I reach the street (long driveway). I have pinpointed it to a shield, GMC is however replacing the entire cat back system under warranty with this complaint as I was at the GMC Dealer yesterday on another issue and queried the SM.

Have a great one!

nhkid28 · May 2, 2003

I think that we are talking about different noises. I have had weights put on my exhaust before and after the muffler and have had the entire exhaust replaced and this did not effect my driveline noise. Shaners has/had the same noise as me and luckily his dealer fixed it by raising the torque converter lockup speed to about 45 mph from about 37 mph.

Like I stated in my ealier post I did get some relief my using Mobil 1 ATF and Lubegard Red. Now I can go days and sometimes weeks before I hear the noise. But it is still there.

Good Luck

jth7186 · May 3, 2003

Well, the service manager and I both thought we had it pinned down to a loose heat shield, but that didn't stop the problem.

All I know is that two bearings and a sleeve in the transfer case have been (or are being) replaced.

The true irony of the whole situation is that GM has me driving a Ford Explorer until they can get mine back to a condition satisfactory to the shop foreman (apparently he doesn't want to see mine again so he is being a little particular with what they replace).

I'm not complaining, yet. Things go wrong. I just hope it doesn't happen again.