problem with mk gti 1.8T

[kingmatt1st]

hi can any body shed some light on this problem i have? today my car keeps losing power and the temp gage is going right up to 130c and the light coolant light has come on. as soon as i stop for a minute it goes straight back down to 90c but as soon as i start driving again it goes higher. it dont seem to hot under the bonnet and the fans dont seem to be coming on either?? any ideas i dont know what to do???

cheers Matt

[toonraider]

possibly an air lock.

[kingmatt1st]

anything i can do about this??? would that cause the temp to go up? could it have anything to do with the fact i got a baily blow off dump valve on??? ive had it on 1month with no problems???

[topher]

sounds like your waterpump has gone. how many miles has the car done?

[kingmatt1st]

the cars only done 53000 miles!!! ive only had her bout 2months! could it be the blow off dump valve or shouldnt this make a difference??

[>>Mart<<]

the dump valve (dv) should not make any difference

as toph said it sounds like the water pump or if the fan is not coming on it could be the temp sensor for the fan

[New Duncan]

I have the video on this situation. Your engine management light will be on, opposite 20mph in the centre of your speedometer. Check the wiring and function of your EM warning light.

Basically, because the temp guage is in the wrong place, it will still read 90c all the time you are driving because air is passing through the radiator, and you get reverse convection.

As Topher says, it is the water pump. Now dont go on cooking that cylinder head - for heaven's sake. These heads don't like getting hot.

The water pump impellor falls off the back of the pump drive and into the pump body. After that you get reverse convection, cos the water in the head is boiling and in the radiator it is maybe 60 or 70C  or less. With the impellor off - (like a propellor screw) water is not being moved through the head drillings (waterways) and the guage may read water going the wrong way back from the radiator.

Get that water pump replaced immediately. The damn thing is plastic and the drive spline goes - even the replacement brand new pump has a plastic impellor (even though VW have done some mods on the later part). VW Dealers will not fit a metal impellor that you can get from GSF.

I have been there at only 49k miles. It is  enough to drive you hopping mad and very pissed off if you have been going up the motorway for a 100 miles or so, or going on Holiday.

Whilst you are there doing the pump - get the cam belt and the cam belt wheel tensioner changed at the same time - IT IS ALL IN THE SAME PLACE.

If you attend to the water pump now at a Dealers, it will cost you £320 or so, and another £320 when you do the cam belt. The labour is 2.9 hours for the same job. Get them all done at once for £375 if you are going to the Dealer. You have at the same time, got to have an engine mounting bolt, because the engine has to be jacked up on one side to get the front cover off - to get to the pump and cambelt. Look out for any engine mounting vibration (which may be a tad more) after the work is done.

I'm pissed off because I saw it coming - but thought it would be ok to leave for another 2000 miles or so  . It is not advisable to pass more that 50,000 miles in any circumstances. Get it done and whilst you're about it, give VW one hell of an earbending from me.

Any more cooking on the head and your engine idle will not be even. I need to investigate this on mine - She does not run as sweetly as before, and circumstances forced me to employ a Dealer to repair, instead of my usual and brilliant Technician.

HMMMNN