Sudden Temperature Increase!!!

[rosco]

My '02 1.8t passat suddenly increased in temperature last night til it was telling me to STOP and check the coolant level. I did this and the expansion tank was literally boiling.
I let the engine cool down and then topped up the system with water but the car kept doing the same thing til i got home. I checked the expansion tank this morning and added a litre of water to it. The car is now at my work til i find out exactly whats wrong with it. The short journey to work didn't give it a chance to heat up in the slightest.
There was a very slight white residue on the oil filler cap and on the dipstick when i checked it last night but there is no sign of any this morning. Also, last night the heater in the car would not work til the car was literally at boiling point which if i remember rightly is a sheer sign of head gasket trouble.
What is the next step to prove the cause of the problem? Can i pressure test the system and can i carry out a Sniff Test on the car?
PLEASE HELP!

[cazyp]

You either have a leak in the cooling system, allowing pressure out and lowering the boiling point; a leak in the oil cooling allowing water into the oil (hence the 'mayo')/viceversa or a failed head gasket.
A garage can test the coolant for exhaust gasses etc. (sniff.) or pressure test the head.

[snapdragon]

Sounds to me like the water-pump may have shed it's impeller and the water is only moving round by the power of convection or carried by the bubbles of the water boiling. Alternatively, the head gasket could have blown instead or even subsequently. You need to look to see if coolant is being pumped into the header tank after starting from cold. If it isn't, it may be the water-pump.

[passman]

This just happened to me? It was diagnosed as a water pump impeller failure and also causing the head gasket to go. new water pump and head gasket I'm afraid.

[mister kloot]

how can you check the water pump impeler, is it something you can take off and check in situe?

if theres an answer id apreicate a message. my 1.8t is doing the exact same thing as this.

thanks.

[martin1810]

You can take off the waterpump but as it's driven by the cam belt you will have to take that off as well.