I just got my first diesel. It's a '94 w/ a 5 spd and 192K miles. I recently towed with it (1200 miles round trip, ATV in bed, towing car trailer with a 4k lb. truck on it), and noticed a noise after about 350 or 400 miles. I had it in 5th with the cruise set at 70. The noise is hard to describe - more solid sounding than an exhaust leak but not too metallic. Kinda like a valve clearance issue or a dead lifter and it only occured under higher boost levels. It wasn't too bad but bad enough for me to shut the cruise off and try to make it "work" less.

Any ideas on where to start looking/listening? I searched earlier but didn't come up with much. Sorry if I missed something.

Thanks,
Ryan

 

Maybe you just noticed it after 400 miles because you werent paying attention, then you heard it and it was all you could concentrate on.

These motors make all kinds of noises.

It won't be long before you know when and where each sound will come from/happen.

 

Nah, it was a new noise. My wife even asked "what's that?" as it got louder. I was able to keep it from happening by getting a run on a hill and then easing up at light throttle. It seems to be boost related or at least load related.

 

Check for any leaks or signs of running different?

Can you get it to do it at idle?

Maybe a U-Joint on its deathbed?

 

Could be a boost leak.. Hard to say. You might just want to check all the hose clamps to/from the turbo, intercooler and intake to be sure. Also the intake manifold bolts have a tendency to come loose over time and can make funny noises under boost.

Gauges?

 

I can only get it to do it under load. Part throttle, idle, cruise, etc... it sounds great. It never ran bad, it just made the noise at times. Definately not drivetrain noise though. I checked for leaks and for blown out gaskets on the exhaust.

I'll have to check all my intake gaskets and connections from the turbo to the intake sometime this weekend. I'll also check for loose bolts. If I don't find anything I'll load up the trailer and see if I can duplicate the noise and maybe get it on video.

No gauges yet. I'll have em soon though. I also need to do a bunch of maintenance - oil change, fuel filter, valve adjustment/check, etc....

 

lift pump?

 

when was the fuid changed in your tranny. they will make a racket under load and when loaded when the oil is weak or low