engine rattle/vibrate

[awh21]

i have a 99, auto, v6 sohc, and i have had it for about a year now. it has 80,000 miles on it and i have started to notice a rattle at low idle(600-700rpms). not only will it rattle really loud but the car will vibrate. it is totally random but will only happen at real low idle, it doesnt matter if if its in gear or park.

i would love to find the problem(hopefully not bad)

thanks, alex

 

[Russ in CT]

What rpm is it idling at? I'm thinking maybe its just too low idle speed, and that results in the vibrations, along with maybe a heat shield rattle (on the CAT or other exhaust part).

If it is idling too low, remove and clean your IAC valve (Idle Air Control), then after you reinstall, set the idle speed. Actually, go ahead and clean the MAF sensor and throttle body while you're at it.

You can use thottle body cleaner for the TB and the IAC valve, but get some actual MAF cleaner for the MAF sensor.

When its rattling, get under neath and see if you can locate the loose heat shield. You can try putting pressure on the shields one at a time to see which one is rattling. Use gloves or a block of wood, etc to apply pressure.

 

[awh21]

thats the thing ive gotten underneath it and its not in a place were i can put my hand. its like up in the engine some were. its not like underneath the truck were i can find the rattle. the part that really scares me is that sometimes it will vibrate the whole car. so like even people in the passenger seat and the back can feel it

 

[Wrench]

Could be the camshaft chain guides degrading as per warranty issue on the early SOHC engines. There is a kit for the front and rear chains.