Tick over slightly high

[John1292]

Hopefully someone can help. Recently my car seems to be running at a slightly higher tickover. Just over 800rpm. It used to be under 800rpm. Could there be an issue? It's a 3.0tdi.

[Steve Q]

How long have you owned the car? It could be due to the colder weather. If you've had it more than one winter then you'll know what it idles at in winter. My other advice would be a diagnostic check to see what fault codes flag up. 

As a long shot the MAF sensor could be on the way out. 

[John1292]

Iv not had the car since June so I don't know what it would normally do in the colder weather. I will wait for the warmer weather and assess it then. No codes on VCDS. 

[Magnet]

Hello John,

It would seem by your description that the variance in idle RPM is marginal around the just-above, just-below 800 rpm. Diesel is rather variable density wise in relation to temperature, and although I wouldn’t claim this to be an influencer, if it were mine, I would not be too worried about it at this stage.

Kind regards,

Gareth. 

[Ade Taplin]

Hi Gareth 

We have a 2.0 Q5 auto that also idles too high just below 900 rpm which makes it a bit juddery when parking, also it doesn't get to temperature it runs about 72 degrees C. Would you suggest that the thermostat is at fault for both symptoms.

Regards Ade 

[Magnet]

Hello Adrian,

Thanks for being in touch. 

If the gauge is reading true at c70 degrees, then yes, you must suspect the thermostat. I would look into getting this renewed, but I would carefully consider the brand of the replacement you are going to use, if not using a genuine VAG one - which is what I would use. Some aftermarket ones can be of variable quality, and could lead to having to spend twice, rather than once and wisely. 

You could try Audi Parts Direct at Cardiff, who would probably do one mail order at discount. 

Kind regards,

Gareth.