Shaking while idling

[mtenderenda]

My car has close to 46,000 miles...I have the Under Drive Setup on it....Car runs nice while its moving....But when I am sitting at a light or idling...the car shakes....Its not a harsh shake..I'm thinking its because of the under drive pulley slowing down the engine...Wondering if this will mess up the engine...I know what the reason is behind the harmonic balancer...But is it worth keeping the under drive setup?:confused:

[fastblackmerc]

I've had U/D's on my MM for 3 years.... no shaking.

What make of U/D's do you have?

[RF Overlord]

U/D pulleys only slow the accessories (water pump, alternator, P/S pump, and A/C compressor) and will not cause the engine to shake.

Does it happen only while idling in gear, or does it also happen idling in neutral? How long have you had the pulleys installed? When did the shaking start?

[RCSignals]

hopefully it's not the harmonic balancer problem

[JMan]

Dude,
Don't drive that thing until someone ascertains the balancer and hub are correctly and fully affixed! It may be improperly installed or not tightened securely. That can be catastrophic if not corrected. Not trying to scare you, just looking out for your well being.

Good luck,

J

[Paul T. Casey]

Is this since your change to the Granettelli COPS? Also, check your pm's.

[mtenderenda]

Well today i drove into work....While idling IN GEAR the car was OK....It was not shaking....The harmonic balancer is not the problem...So i'm thinking of using fuel injection cleaner...I've had the underdrive setup in for 2 yrs now....I know its not the plugs they are new...I know that the COPs are not the problem....So ill try the injection cleaner...

[magindat]

Make sure the vac hose under the throttle body is not off, leaking or cracked. Sounds like Idle Air Control to me.

[Paul T. Casey]

Well today i drove into work....While idling IN GEAR the car was OK....It was not shaking....The harmonic balancer is not the problem...So i'm thinking of using fuel injection cleaner...I've had the underdrive setup in for 2 yrs now....I know its not the plugs they are new...I know that the COPs are not the problem....So ill try the injection cleaner...

Check your pm's again.

[Raudermaster]

Try to clean your MAF. My car had a slight rough idle, but not shaking until I cleaned mine.

[Todd]

Well today i drove into work....While idling IN GEAR the car was OK....It was not shaking....The harmonic balancer is not the problem...So i'm thinking of using fuel injection cleaner...I've had the underdrive setup in for 2 yrs now....I know its not the plugs they are new...I know that the COPs are not the problem....So ill try the injection cleaner...


You may want to pull your plugs and check the gap just in case. Just make sure nothing happened to one of them to significantly close the gap.

[bigjon]

do you notice the issue when you are sitting at a red light with your foot on the brake or when your car is in park?

[Mad4Macs]

Shaking while idle? It's called having "DT's". Nothing that a shot of alcohol can't cure ;)

:beer: