Hi All,

I need help diagnosing a rattle that I believe is coming from the front half of my truck. I have a 2003 RAM 2500 SLT 4x4 Heavy Duty with a Cummins Diesel engine. The problem is an intermittent rattle that seems to come from the front half of the truck. It does it whether the road is rough or smooth and is most pronounced at 25-50 mph. The rattle does not occur if the truck is sitting in park, not even if you rev the engine to 3000 rpms. There was also a point last Friday where the truck backfired and had a couple periods of lost power.

About a month ago (before rattle started) I had U joint replaced to fix a "clunking" noise during turns. That was done under warranty and fixed that problem. I have taken the truck back to that service center (dodge dealer) to have them try and diagnose the rattle but they can't find anything. I've also taken the truck to a second dealer service center and they have gone over the truck twice with no luck. They have replaced the air filter and fuel filter (apparently that is what caused the backfire and loss of power), flushed the transmission and checked out all the components that commonly cause a rattle (i.e. shrouds, hangers, pulleys, etc). They can't find anything.

I myself have spent a couple of hours under and in the truck poking, prodding, yanking and banging on anything I could reach to try and find anything that was loose. The only things that I could get to move seemed like they should have play (i.e. normal). The only questionable items were the driveshafts (front and rear) that had a little play and I think that is normal and the steering column having the slightest amount of play. Everything else is solid - exhaust, brakes, tires, brake lines, braces, mounts.

The rattle itself is definately intermittent. It is not consistent or patterned. It sounds random. Definately sounds like metal on metal and has almost a hollow quality (and yes, I've checked the exhause from the manifold to the rear pipe). The sound itself is best (and very accurately) described as pennies in a coffee can.

I am about at my wits end on this. Any help or suggestions would be greatly appreciated.

Thank you,

Al

 

does it do it at idle???

how many miles???

have you noticed a decrease in engine performance and an increase in smoke from the tail pipe when your taking off???

have you noticed your fuel mileage going down???

if it does it only at idle youve got a little carbon build-up that needs to be burned off. find a hill and floor it going up a few times, dont look at the tail pipe, you'll see alot of soot and junk, but just keep the throttle to the floor.

if you have over 150K it is time to check the valve lash and it could be that is what you are hearing.

if fuel mileage has gone down, or performance has decreased you might have a stuck injector.

 

The truck has only 63800 miles on it. I really don't think it's carbon buildup.

Also, it doesn't do it at idle. It doesn't do it when the truck is in park at all, even if you rev the engine to 3000 rpms.

It only does it when the truck is in gear and travelling at over 20 mph. Or at least, that is the only time that I hear it.

 

I don't want to freak you out, I don't think this is the problem but that sounds exactly like when my engine swalled a valve, all the exact same symptoms. It actually ran for about a hundred miles after it happened too. Like I said, I wouldn't think that's the issue, but maybe focus on the head of the engine being the problem, do some listening there, and see if that's the source. Sometimes you don't need to know what the problem is, just where it is and that solves 90% of the worry.

 

The dealers who couldnt find the problem. Did they take it out and drive it in order to duplicate the symptom?