Engine shake when switch off aircon

**tyberwan** · 03-08-2009,10:21 AM

Hi

My car engine shakes after driving when I switch off the aircon or if aircon is on "Econ" mode. If the aircon is on, it gets smoother and does not shake.

The garage says it probably is the engine mount. Where is it located and how does it get used/damaged? Any problem in not changing it as it does not bother me because I use aircon most of the time.

thanks

**Dave Avant** · 03-08-2009,10:45 AM

This has been talked about lots before and there doesn't seem to be a specific answer. Some say a new engine mount cured it. The engine mount is electronic and its firmness is controlled depending on engine revs to get the best damping from the mount. Some have said the calibration of the injectors. I've heard the tensioner pulley on the auxillary belts can make it shake. Temperature sensors?

I gave up looking for the answer on mine, although I haven't noticed it that much recently.

One thing that did come up about the engine shake was that it seemed common after a cambelt change!?

With mine it only did it when the outside temperature was atleast in the high teens, engine fully warm and on ECON.

**tyberwan** · 03-08-2009,12:09 PM

I agree with you - when the engine is cold, there is no shake. It starts shaking after it gets warm after 15 mins.

What I would like to know is, do we need to change it if it does not bother me (I can leave my aircon on)? Any further damage this could cause if I do not change it?

thanks

**Marco34** · 04-08-2009,09:29 AM

I had my cambelt changed 3 years ago and it started then. I've drained resources as to what it could be, no fault codes for engine mounts etc. I wasn't throwing money at it unless I knew exactly what it was.

3 years and it still shakes but only when hot and ambient temp warm outside! I've come to the conclusion of sod it!

The car runs sweet otherwise!

**Dave Avant** · 04-08-2009,09:44 AM

Must admit, not noticed it much this summer and after the remap, noticed it the other day, but it wasn't as prominent.

Most of the time at the lights if I have the radio on low I think its cut out its so smooth even with no diesel vibration.

**tyberwan** · 04-08-2009,10:41 AM

Came back from garage. They said there are 2 engine mounts and one of them is damaged, that's why the reason of the shake. However, when putting the aircon on, the shake goes away. They say it's because with aircon on, it demands more load from the engine, that's why the shaking stops.

Will need to change that engine mount some day.

**A6TYY** · 04-08-2009,05:21 PM

i got the same problem with mine, i cleaned out the egr valve the other day and since then its near enough gone, does come and go but is very very soft compared to b4 the cleaning.

**tyberwan** · 01-11-2009,04:02 PM

Changed 2 Suspension arm bushes at an independent dealeras I was hearing a knock every time i travel on uneven roads. This cured the engine shake almost. Pitures attached and they look like split.

That's strange because at the Audi garage they said an engine mount was required. Is it the same?

thanks

**Dave Avant** · 03-11-2009,12:24 PM

Not sure how this would cure an engine shake, its not connected to suspension mounts.

Need to check my mounts actually, getting wandering, tramlining and knocking over bumps. and torque steer, but that might be the remap

Mine's not shaked for a while. The guy who did my remap mentioned the pulleys and tensioners being worn as they may create 'tight' spots when running, like a chain on a bike putting a tiny bit of intermittent load on the engine making it shake.