Over reving engine

[GillyGTI]

Hey Guys
I have a 1991 mkII 8 valve GTI and I am having problems with the engine seriously over reving on start up. It takes about 5 miles for the revs to drop.
Anyone help with this ?

[Mk2Kezza]

Try replacing the blue temperature sensor - you can get them from VW  for about £14 (Part no 025906041A). Its located in a plastic housing on the front of the block and has wires attached to it.

[cняis]

get a new O-ring aswell.

you cant get the sensors online anywhere (except GSF which are reportedly of crap quality) plus theyre cheap enough from the dealers.

dont change the sensor when the engine is warm though.... mmm scoulded hands!

[mattneck(Beavis)]

get a new O-ring aswell.

you cant get the sensors online anywhere (except GSF which are reportedly of crap quality) plus theyre cheap enough from the dealers.

dont change the sensor when the engine is warm though.... mmm scoulded hands!

you can ge them via me tohugh if you wish, ill ahve to confirm a price, but ours are genuine 

only difference is the part numbers been filed fof so they can be sold on the aftermarket, cheeky, really 

[cняis]

get a new O-ring aswell.

you cant get the sensors online anywhere (except GSF which are reportedly of crap quality) plus theyre cheap enough from the dealers.

dont change the sensor when the engine is warm though.... mmm scoulded hands!

you can ge them via me tohugh if you wish, ill ahve to confirm a price, but ours are genuine 

only difference is the part numbers been filed fof so they can be sold on the aftermarket, cheeky, really 

wish i'd known this before i got mine! 

but my local dealers did offer free next day personal delivery, cant complain at that.

[Godzilla]

get a new O-ring aswell.


dont change the sensor when the engine is warm though.... mmm scoulded hands!

Could changing the blue temp sender when the engine is hot kill the new sendor?

Also O-ring, does this live in the idle screw bit?

[cняis]

get a new O-ring aswell.


dont change the sensor when the engine is warm though.... mmm scoulded hands!

Could changing the blue temp sender when the engine is hot kill the new sendor?

Also O-ring, does this live in the idle screw bit?

no the O-ring seats between the blue temp sender and the plastic housing to form a seal.

changing the sender whilst the engine is hot will not hurt the sender, but i will hurt your hands as the water will be hot!