Yummybud924

okay heres the problem, my motor mounts are still fairly new about 8,000 kms and one year old. I replaced them with ones from the porsche dealer who charged me I think 135 dollars for each one and they told me it's oem but later I found out that they are the ones that pelican sells as aftermarket, mehle or mahle brand.

anyways I'm having idle issues as well, sometimes my idles dips too low or too high. When it idles less than 1000 rpm I have noticable vibrations and when you look at the engine you can see it shaking.

when driving it's pretty smooth. This sounds like motor mounts but these mounts were 135 bucks each from the dealer even if they are the ones listed as aftermarket on pelican and the place I go tthem from works on 944s and said they haven't had any problesm with them.


So what else could this be due to other than mounts? I really don't want to replace motor mounts again. It was a major pain putting in new motor mounts I never want to do it again lol.


However if it is mounts I may have to buy new oem ones again from pelican this time and pay the shop to install them. how long would labour be?


is there a way to raise my idle a tiny bit to make it smoother?

I wouldn't mind it idling at 1100 rpm to 1000 rpm. right now it usually idles at 850-900 rpm and sometimes rises to like 900-1000 rpm. not sure what is causing the changing idle, I replaced all vacuum lines and idle stablilizer.


I'm worrried that teh virbrations may causes future fuel leaks or even crack something like the oil pickup tube. I already had the alternator adjusting bracket snap in half.

Dinman_UT

It's funny that you mention increasing the idle speed to fix the vibration because I think that's what my PO did. I adjusted my idle speed back down to 900-950 rpm, and just deal with the vibration until I can replace the motor mounts. Anyways, the procedure to adjust idle speed is at http://www.clarks-garage.com.

austin944

I would first try checking the mounts using the procedure in Clark's garage:
http://www.clarks-garage.com/shop-manual/eng-11.htm

jstand22

Maybe the balance shafts are slightly mis-alisgned, or incorrect tension on the belt?

Spidey944

A spark or fuel injector issue would be much more prominent at low rpms than at high rpms. Have you had the injectors cleaned or the wires replaced recently? Your mounts should be fine, your vibration is being caused by something else. I also like the balance shaft idea posted by Jay.

Yummybud924

yeah I'm not sure. have not professionally cleaned my fuel injectors but I did run some techron in my gas and yesterday I tried redline fuel system cleaner in my tank.

my spark plugs are bosch ones and are a year old, spark plug wires , cap rotor are all new. Also just replaced the idle air stabilizer.

so not sure what else it could be. someone told me it could be carbon deposits or gunk in my throtle body?


sometimes when I rev the engine the idle stays up really high like at 1800 rpm and keeps on rising then suddenly it falls back down or goes down too low.

at 900 or less rpms the vibrations is pretty bad, you can see the engine shaking and you can feel it inside the car.

maybe I should clean my throtle body next? how would I do that?

Yummybud924

I was also thinking of changing out the spark plugs again maybe try NGKs, BPR6es over the Bosch. Right now I have the Bosch wr7dc and they are like 2 years old and like 10,000 kms on them.

s.i.s944

I've have the exact same problem but mine only occurs in the morning when the car is cold, once the arrow moves into the first box on the temperature gauge it idles just fine. I've changed plugs, and wires. The cap and rotor is fine, and I just got new injector seals. Could it possibly be motor mounts?