fluctuating RPM when cruising - cold start

[esandes]

i think the revs fluctuate +/- 100 RPM when cruising from a cold start with the engine still cold. TPS problem? transmission problem?

[B72011]

I thought you were banned? Or was that from VW Vortex? Could be torque converter in trans, leaking air.....

[Cantalk]

Tiptronic, CVT or manual? Need more info. What speed?

[80sGuy]

Might be PCV going out...wait for the infamous whistling....

[esandes]

Tiptronic, CVT or manual? Need more info. What speed?

tip. it can happen at any speed. i gave it an italian tune up and it seems once the engine warms up it stops.

[Cantalk]

Sounds like your torque converter is on its way out. Tons of threads detailing this situation.

[FormulaElement]

Its the torque converter like others have said. Its not worth changing until it starts shifting hard... I just changed mine because of this and hard shifting. When it was 0˚ or below i was getting around 400 rpm fluctuations.

[yeoj112689]

I have (what i think is this issue) as well. Cold starts only, for a few seconds, I can feel a bit of a pulse when driving (nothing big just annoys me) but according to VAGCOM my RPMs stay at 760 without fail so idk maybe I am crazy.

So make sure you know what it is before diving into the money pit that is throwing parts at cars.

[esandes]

I have (what i think is this issue) as well. Cold starts only, for a few seconds, I can feel a bit of a pulse when driving (nothing big just annoys me) but according to VAGCOM my RPMs stay at 760 without fail so idk maybe I am crazy.

So make sure you know what it is before diving into the money pit that is throwing parts at cars.

what milage does yours have? mine's at 107k. just started happening a thousand miles ago or so.

[yeoj112689]

what milage does yours have? mine's at 107k. just started happening a thousand miles ago or so.

87k

[esm]

I had a thermostat failure on my car that seemed to make the problem worse, particularly in the winter. Once the stat was replaced during a recent timing belt job, the fluctuations seemed to diminish. I don't even think they are noticeable anymore during my normal warmup period, which is now really quick. My theory is that if the car isn't warming up properly (due to an old/broken thermostat), it makes the warmup cycle take longer and may contribute to slower warmup for the transmission. YMMV.