This is my second '99 (the first was an Amigo). Both are/were V6's. There is a loud tingy vibration type noise when accelerating (from a stop) until the engine RPM's come down. The sound is coming from the front (engine compartment I would guess). Sounds like a piece of metal vibrating against another piece of metal. Exhaust? Fan shroud? ???

Anyway, since this is my second V6 with the same problem I figure it must be something that alot of people have experienced. Anyone know what this might be? Like to get it silenced...

Sounds like a heat shield. Since the internet is a poor medium for transmitting sound, I would suggest you take a moment and crawl under there to find out what it is.

Michael

THERE AREA COUPLE OF THINGS UNDER THERE THAT WILL CRANK AND BREAK LOOSE AND RATTLE DEPENDING ON ENG RPM, EXHAUST HEAT SHEILDS ARE VERY COMMON, BUT ALLSO TAKE A LOOK AT THE BACK END OF THE TRANS THIS WILL ONLY APPLY TO A 2WD UNIT , WHERE THE TRANS SITS ON THE REAR MOUNT , THERE IS A SQUARE BRACKET BOLTED TO THE MOUNT ITSELF , AND THEN ANOTHER BRACKET THAT GOES UP OVER THE TRANS IN A SQUARED CORNERED LOOP, ALL MOST THINK IT WAS A DRIVE SHAFT SAFETY LOOP, BUT IT IS FOR NOISE HARMONIC CANCELING , AND THEY ARE NOTORIOUS FOR BREAKING AND RATTLEING , IF IT IS BROKEN JUST TAKE IT OFF AND THROW BOTH PIECES AWAY, YOU WILL NEVER MISS THEM, I HAVE SAW A COUPLE OF THOSE THINGS BREAK AND FALL DOWN ON THE DRIVE SHAFT AND ACTUALLY CUT THE FRT OF THE DRIVE SHAFT IN HALF, AND NO ONE EVER SEEMS TO HEAR IT UNTIL THE SHAFT FALLS OFF, IT IS MADE OF ALUMINUM SO IT DOESNT TAKE LONG TO GET MESSED UP . JERRY

how does that work?

thanks

//bc

THE UPPER LOOP , THE ONE THAT GOES UP OVER THE DRIVE SHAFT IS VERY THIN ,AND FROM WHAT I CAN GATHER AT THE POINT THAT THE DRIVELINE WOULD MAKE A NOISE , THIS LOOP WAS MADE TO VIBRATE AT EXACTLY 180 DEGREES OF THE FREQUENCY OF THE NOISE THE DRIVELINE WOULD MAKE AND BEING 180 DEGREES OUT OF PHASE IT WOULD CANCEL THE NOISE , EVIDENTLY IT WOULD WORK FOR A WHILE AS THE VIBRATIONS IS WHAT MADE THEM CRACK, , THE REPLACEMENT IS MADE ALLMOST THE SAME WAY BUT STIFFER , I HAVE TAKEN THEM COMPLETELY OFF AN D I CANNOT TELL THE DIFF ,IN MOST DRIVING INSTANCES, THE RODEO IS NOT THE QUITEST VEH IN THAT PARTICULAR AREA ANYWAY , JERRY

Just took a 1100 mile trip and dealt with the noise most of the way. At 750 miles the IDLE A/C pulley bearings collasped, the pulley wobbled, and serpentine belt came off leaving me running on battery as I limped into the nearest town (20 miles). Fortunately, I had a new battery (lost alternator charge as well as everything else) as it was 11PM Sunday and I was running with the headlights on. I haven't swapped out the pulley yet but I suspect the noise might have been the bearings going bad. But... I did notice that the whining/vibration noise only happens around the normal shift point (2500 RPMs). Just another clue. I'll follow-up later to let you know if replacing the pulley cured the noise problem. Also, I've now got a check engine light on (happened around 700 miles). Anyone got a post for getting/reading the diagnostics?

Ok... New pulley ($12 autozone) and belt ($40 napa) and I'm up and running again. Check engine light was still on after the repair but went mysteriously out after 2 minutes of driving. I also changed out the PCV and fuel filter while I had it in the garage. Don't know if those could have been the cause for the check engine light or not. Anyway, tingy vibration sound still exists at ~2500 RPMs. Hoping to track it down this weekend...

OK. I've finally got the noise nailed down to specifics...

Passenger side exhaust, just before the cat converter, there is a heat shield around the exhaust pipe around the sensor that when I clamp a vise grip to the noise stops. I tried bending it around a little, putting pipe clamps around it, etc., but the only thing that works is the vise grips. Any ideas?

why dont you just take the heat shield off?

because it will cause the floor right above it to get really hot, can cause the frame by it to worp or become weaker from the heat. burn a hole through the floor board. stuff like that.