Hi all,

Here's a question/problem from a new guy. Sorry if it has been addressed elsewhere, but I can't seem to find any info.

I recently purchased a 2000 Ram Van 1500 5.2l V8 with 154K miles. I have been driving it for a few hours a day during our current move. The engine runs great with no noticeable noises. It is solid, and very smooth at idle, normal driving and highway speeds. I can drive it right now around town and no issues.

BUT a few days ago (and since) after I drive it for approx 30+ minutes on the highway (70 mph) it makes a seemingly random but very noticable series of "clunks" that I can feel under my feet. I'm not sure the proper term for the noise... thunk.. thud, umm knock. My wife says it sounds like a seat belt flapping around under the car... as good a description as any. The noise starts low, then jumps to a louder volume then stays there. It isn't all the time, or with bumps or any sort of pattern. "Thunk....thunk, thunk..........thunk..." The first time it happened I had been cruising along the highway for 35 mins or so at about 70mph (cruise control on) and it started. I turned off cruise and coasted and it didn't change the severity or rate. So I pushed it a bit, no difference, still there. There was no loss of power, no gauges moved and no engine or other dash lights. When I got off the highway, and stopped at a light it stopped as well, but when I started moving again it came back.

I got to where I was going no problem. The van sat there for a few hours, and I had to make my worried return trip. Smooth and quiet for 25 minutes at 70mph. Then "thunk... thunk, thunk..." again... nothing changed, still had power, no dash lights or gauge issues.

I have checked the fluid levels, and everything was fine. I have driven this route a dozen times in the past week with no issues, until it first happened, now it happens every time I make the trip. I can drive it right now and it won't happen until it runs at speed for a while.

I'm almost afraid to take it for service anywhere as it can't be repeated until it's driven for so long. This (in my past experience) can result in changing many "bad" parts with no change in the problem.

Does anybody have any ideas...?

 

Have both sides of the front brake rotors inspected to see if any chunks of the surface material broke off. My daughter's car did this and it drove me nuts trying to find the noise. I finally removed the rotors and found a chunk of the surface missing on the backside. My next though would be the drive shaft, but that tends to be a much faster noise than road noise.

 

Thanks for the quick reply, I'll have a look at the brakes and see what we find.

 

If he stepped on the brakes at speed with the noise, should the noise go away with moderate brake pedal pressure?

I was also wondering if the charcoal cansister might be loose and possbily causing the noise? Since it is behind the left wheel well on the 98 and newer vans.

 

......

 

Thanks again for the info. Some great ideas all around.

Guess I'll be checking some stuff to see what's loose. Fairly sure I have applied the brakes and still had the sound happening. I can rule out spare tire, as there isn't one hanging at the moment. I was trying to think of things that may heat up over time, but possibly the canister would could move around more after more use. Its the idea that it doesn't happen most of the time that throws me. Not sure, but we'll see.