944 S2 stumbling idle and vibration

was8v · Jan 31, 2009

Just been to see a really nice S2- the car has not been used much (2k miles in a year).

Issues:
1) Slight "hesitancy" when flooring it from low revs. It seem to stumble a bit then take off.
2) The idles fluctuates constantly. Is this just a gummed up ISV?
3) The vibration at idle from the engine (not helped by the fluctuating idle) can be felt through the whole car.
This vibration goes after 1500 rpm - this leads me to think the engine mounts need replacement after reading clarks garage / 944 FAQ. How much are the parts for this?

Other S2s i have seen have been cosmetically tatty, but the engines have been smoother than this. Can anyone confirm the diagnosis above / tell me more?

Thanks.

zcacogp · Jan 31, 2009

If it's not been driven much in the last year then 1) could be simply that. A service, new plugs and oil, and a good drive may well sort it out.

I'd say you are probably correct with 2) and 3). Both common problems. Engine mount can be a difficult job and may cost a bit - get a quote from an indie before you buy and use it as a tool to get the price down.

My S2 really didn't like not being driven much. Since I started doing 15k miles a year in it (i.e. for the last 2 years), it has become a much nicer car to drive. If the car you mention hasn't had much exercise then it could well be similar.

Oli.

RC18B 911 turbo · Jan 31, 2009

Mine used to do that when it hadn't been used for a while and was simply the ISV and after a good clean out all would be good again.

Big Dave · Feb 1, 2009

The hesitancey,, "might" be the Air flow meter getting old...The usual barn door / metal strip problem.
The vibration "might" be that the balance belts could be a tooth out , OR even 180deg out....When were they last done. PS even qualified mechanics can get the balance belts wrong.....[8|][8|][8|]

was8v · Feb 1, 2009

Thanks everyone. Wow the mounts are expensive.

Pelican parts will do 2x non genuine ones for about £85ish delivered fromt he states - are they really bad quality?

I'd look to measure them (according to clarks they should measure 60mm) and replace them myself before passing the car to a specialist for belts and inspection for other things I might miss.