My car vibrates intermittently when stopping at stop signs,stop lights,etc. I read another post and 2 people said that they had that happen be4 and changed the battery, then it was gone. The car is 99. I was looking at the optima red top from costco but i dunt want to buy it until i kno thats the problem

 

I don't see how a battery can help that, try cleaning your throttle body.

 

mine does this periodically, theres no pattern. The RPMs are still above 550-600, but it gets slightly coarse, then goes away for awhile, then shows up a few days later...odd...



eric

 

I believe the ECU has problems when the voltage drops too low. I have replaced 2 faulty batteries (shorted cells) in the last two years. I was getting a whining noise from the ECU that matched the rpm. And bad milage, missing cylinders and CELs. New battery go in, whine is gone, milage is better. What the ECU needs (and headlights) is a DC power conditioner. Any ideas?

 

have you checked the spark plugs? IACV? Starter? Alternator? There's a million things that can cause a rough, low idle.

 

99's also have a problem with coil packs. You will get symptoms as you describe--rpms normal but car sputters like it's misfiring ie. operating on 5 or fewer cylinders.

 

my bet goes to IACV

 

Mine did the same thing, except my SLIP and Traction Control light lit up. I checked the ECU and it gave me a missfire on coil 2. Took it to the dealer and they said the second coil was bad. It was covered under warranty and they ordered the part. I will let you know if this resolves the problem.