pvansh

I posted a thread on this a while back but never really found anybody who had a similar occurrence, so I thought I'd give it one more try.

I have an '05 5AT.........when the car is cold (overnight or longer) and I start it up, it idles and drives rough. However while driving the car, once it warms up, this rough drive does not go away. Of course the rough drive is even more prominent at the normal vibration points (i.e. 1500rpms).

On the other hand, if I start the car and it is already warm, then the car is very smooth throughout the drive.

So basically, when the car is started cold, it drives rough and doesn't go away until the car is re-started warm.

Anybody else come across this ????

Thanks.

willz822

I have pretty much the same issue except I have the 6MT. It'll idle rough when I first start the car in the morning. Eventually it will smooth out but not entirely. I can still feel a little vibration in the steering wheel.

pvansh

So it stays with you as long as the car is running, but if you start the car warm, you don't experience it, correct?

Have you taken it up with the dealer or do you have any hunches as to what it could be?

willz822

I've mentioned this to my dealer once who gave me the usual reply that they did not feel anything. From all the posts on this forum, I'm thinking maybe it's the heat shield, engine mounts, or just a case of bad design.

I've pretty much gotten used to it by now but I'm probably going to take the car to a mechanic friend of mine and see what he has to say.

pvansh

What I don't understand is, why does it only happen when started from cold? If it were mounts or heat shield, I think it would happen all the time. I'm thinking possibly the ECU?

At any rate, if you do find out, please let me know so that I can try and fix it on my TL as well. Thx.

pvansh

Anybody else?

Brettg

There are a few things to seperate out:

When cold, the motor mounts and other rubber bits are cold and stiff, this
will introduce engine vibrations into the body of the car.
The engine also runs a bit rougher when cold, like most cold engines.

The tires can flat spot after sitting.
Some tires are MUCH worse at this then others, it depends on
what the belts are made out of.

The auto trans has some built in drivetrain vibrations I hear.
These may get worse with stiff motor and suspension mounts.

I can see all these problems combining on a cold day to really
cause an unpleasant ride till things warm up.

On my 6mt, I have noticed the stiff motor mounts, that goes away in about
5 minutes, and very minor flat spotting of the tires, that goes away in about
5 miles....
I dont have any driveline vibration.

Brett

willz822

When you say go away after 5 minutes, do you mean the car is completely vibration free? There is no vibration felt thru the steering wheel at all? My car used to idle rough but it would go away after a few minutes. That was when I first got the car. Now, the vibration will subside but I can still feel a little vibration in the steering wheel. Pretty minor but still annoying at times.

Brettg

On my car, after 5 minutes on a cold day, there are no vibrations at all, at
any speed.

In the summer heat, it does not seem to have any vibration at any time.

Vibrations are something that really bug me, and they can come from various
sources, some are not easy to fix.
Tires are the most common, but they make the hunter road force for that.
Driveline problems can be a real pain, I had to replace the driveshaft
on the Jaguar as the center mount started going.

The passat had a vibration through the body at idle, the engine thrust mount
and the automatic transmission were the issues there.
Fortunetly, it mostly went away when it warmed up.
On that car the engine was NOT transverse, so at idle, it pushed the motor
against the thrust mount.
When moving it was always very smooth.

I really like the fact that the TL is so smooth, at 20 mph, at 80 mph,
even when full throttle and higher rpms, its smooth.
Its not as quiet, but if you turn up the radio, you have no idea what the engine is
doing without some audio feedback.

Brett

willz822

My tires are not the cause of the vibrations since I can still feel it when the car is idling. I have noticed at times however, that after some spirited driving the vibrations go away....only to return a short time later. Possibly an engine mount problem.

pvansh

willz, can you confirm that you problem stays with the car as long as its from a cold start.........but does not occur if it is from a warm start? Just trying to see if anyone has the exact same problem that I do.