1999 Passat 1.8T high revs on start up

[whitejc]

Hi Guys
I'm generally the proud owner of a Passat 1.8T 1999 but... every so often it will rev to about 2000 rpm on start up and after about 2 seconds settles down to normal. It generally does this on the first start of the day. On occaisions it will also not start until it has been wound on the starter for 30 seconds. It's covered 95K miles and has been regularly dealer serviced and is generally in VGC.
Can anyone give me any clues? The main dealer doesn't seem to know!
Thanks
Whitejc

[shooey88]

no faults in the ecu? first obvious thing to check would be throttle body. can cause poor idling and poor starting or stalling.

[whitejc]

Hi Shooey88
Many thanks for the quick reply. I will take a look at the weekend. If there's no prob with the throttle body I don't know how to check the ECU. I've heard there is software available to install on a lap top and do your own diagnostic with... do you know anything of this?
Whitejc

[Lex Luthor]

It's probably the coolant temperature sensor.
Cheap and easy to replace.
It's located at the back of the head.

[whitejc]

Hi Lex Luther
I replaced the coolant temp sensor as suggested... it seems to have done the trick, time will tell. After fitting, the engine started sweetly and settled immediately at tick over. Many thanks. J White