servantsalesmen

Does the truck vibrate when it's not moving? If so, it's likely somewhere in the engine, flexplate, or torque converter.

Are all of these issues happening with chevy's or are some GMC's doing it too? If it's just chevy's then that could help narrow it down.

Measure twice buy once!

Here's mine! 2004 GMC sierra 2500HD. It's a 6.0 long bed extended cab. It has 88,000 miles and is currently broken down. Can't wait to get it up and running again though!

That's frustrating man. Sorry to hear that. Best of luck with this one. Please let us know if you find it

GM uses a crappy stamped steel plate for their flexplates and they can break. It's not super common but also not super rare. Typically a cracked plate is loudest when the engine is running unloaded meaning in park or neutral. When you shift into gear or start to accelerate you put a load on the plate and that force is enough to push it together enough to keep it quiet but the minute you coast and let rpm drop the noise comes back. If it is a flexplate, fix it! Don't let it go. Yes it is possible to put several thousand miles on a broken one but it's a disaster waiting to happen. If it totally let's go and grenades itself, there is a big metal disc heading right into the cab and it will slice through the truck like butter.

Flexplate. That's what I'm calling. Start your truck up and then get out of it and crawl underneath it and try to find the source of the sound. If it seems to come right from the bell housing on the tranny, you probably have a bad flexplate. Mine cracked in like 8 places and sounded terrible.

No its not! Go check out the k2xx suburban yukon forum on here and there is a big long thread on it. But I really hope that it's not happening with the HD trucks too. Lots of these trucks go for north of 60k and that's a lot for a vehicle with separating roof panels. I know what it's like to buy an expensive truck that goes south fast.

Maybe the roof is separating on the cross members like several of the new Yukons...

I feel that pain brother. My truck had the flexplate crack at 80,000 miles. Dealer wanted a grand to fix it. Now I have a truck in my driveway on stands with no transmission, transfer case or drive shafts.

Could the fuel filter be clogged? I might be way off and too basic but if I'm right, it's a cheap and not too bothersome fix

If it was bell housing, you'd know it right away lol! Exhaust manifold bolt wouldn't surprise me.

To me, it sounds like a cracked flexplate. I say that because I had a similar sound coming from my 6.0 and that's what it was. In the video, it seemed to be louder when you were down low. Crawl under there when it's running and listen right around the bell housing on the tranny and if it's real loud and a very sharp, metalic sound, it's a flexplate. Also, if the sound goes away or quiets when put into gear, that could be another indicator because as you apply load to the plate, the force is enough to push the Crack back together, making it quiet again.

I wouldn't trust it.... how long has it gone on? You say it comes and goes with rpm but how about with gear changes? For example, can you hear it more distinctly when it's in park versus drive or reverse. Also, try to locate the sounds origin as best as possible. Top end, bottom, back or front.

2004 Sierra 2500HD SLT 6.0L 4X4, extended cab, long bed. 87,000 miles purchased new. It's all stock with no modifications. Things I'd like to do: Level kit LED light bar up front Auxiliary reverse LED bar Bilstein shocks Footwell lighting

How did you run the auxiliary lights? I have been trying to figure out the best way. Thanks and possible pictures of the switches etc would be awesome. PS. You should do a disc conversion in the rear and put on some powerstop rotors and pads then put on stainless braided flex brake lines at all wheels. I will give a much firmer and immediate pedal

Oh and I forgot to mention.... the beast is 10 years old and has only 86,000 miles on it...

My turn:2000 Suburban and 2004 GMC Sierra 2500HD The suburban has been unstoppable.. until now. It has just over 200,000 miles on it and has has ita share of problems but nothing major. Recently I picked up on a noise from the motor (sister was driving) and turns out that it's coming off the crank area. I parked it and have yet to mess with it but I suspect it is a bad oil pump, broken crank or bearing. Hoping to take it apart and learn about motor building! The 2004 is a heap. My Dad ordered it custom from the factory in 2003. It is an SLT extended cad, long bed. It has 4.1 rear gears and the 6.0 liter motor. You name it, it has gone wrong. The brake lines all rusted through and ruptured (while sister was driving). I replaced them with stainless lines and fittings. On top of that I replaced all four calipers (bleeder screws were frozen) and did rotors and pads. On the unfinished list I have... The doors leak and seat heater controls come on when they please, noisy lifters, rusting fuel lines (badly rusted too),the spare tire safety mechanism rusted and frooze and none of the gauges work. On top of that there are things that cosmetically have gone wrong. The wheels all have peeling clear coat and pitting, the frame is rusting like no tomorrow, the grill chrome is destroyed, the lights are yellowed and the badging is fading. This truck is an embarrassment to GM. I have never seen a final product put together so poorly. After this beast that gets 11 MPG, my next truck will be a FORD.GM just has not shown that they can make a good product. But for now I am stuck with the beast.