A4 B6 2.5 diesel

**chevyshaun** · 25-04-2015,08:32 AM

Hi guys, my Audi takes around 8 secs to start weather it's hot or cold and then ticks over at around 1200 rpm for about 30 secs. I've read the high tick over is to heat up the cats, but if the car is at operating temp why do it still rev high when starting?? Thanks

**Alan02** · 25-04-2015,05:54 PM

Have you had the car scanned for faults?

**abyrne153** · 25-04-2015,06:19 PM

Shouldn't do that. It should only idle at higher rpm when starting from stone cold and then only for less than a minute. I would suspect a faulty coolant temp sensor. Scan for faults but it would sound as though it isn't sending a correct signal to the ecu. The cts only costs about £30 for genuine and is easy to change. No need to drain coolant or anything just change when cold and make sure to buy a new securing clip as they are easy to break when removing.

**chevyshaun** · 26-04-2015,08:54 AM

Originally Posted by Alan02

Have you had the car scanned for faults?

Hi Alan, thanks for reply, yes car has been scanned and no faults found!!

**chevyshaun** · 26-04-2015,08:57 AM

Thanks, for info, I suspected the MFTS, but as the temp gauge is working correctly it made me doubt the sensor was faulty, I'll order one on Monday and will keep you posted. Thanks Again

**zollaf** · 26-04-2015,09:19 AM

you say its been scanned and no faults, but was live data looked at to see what all the sensors are doing. it may well be the cts, its a 2 part sensor, one for the dash and one for the ecu, but you would be able to see this in live data. your call, you can throw parts at it and hope for the best or get a diag computer back on it and get it correctly diagnosed.

**chevyshaun** · 26-04-2015,09:22 AM

Hi zollaf, thanks for your input, I will have it rescanned Monday and look at live data before ordering sensor

**mikeybutch** · 26-04-2015,08:04 PM

Has it done this for long?Mine was a bad starter cos a previous owner had the timing out after a belt change.

**chevyshaun** · 26-04-2015,09:03 PM

Originally Posted by mikeybutch

Has it done this for long?Mine was a bad starter cos a previous owner had the timing out after a belt change.

Hi mikey, previous owner I know, and is a good mech, he has changed belt but it was doing this before that!!

**adamss24** · 26-04-2015,11:36 PM

Originally Posted by chevyshaun

Hi mikey, previous owner I know, and is a good mech, he has changed belt but it was doing this before that!!

Most likely he used the "mark and pray" method to time the engine hence hard starts, he just made sure the iming was put in the same position as before...which might have been wrong !