Advice needed - Overheating

[AlexGSi2000]

Just wondering if I can have a few opinions on whats gone wrong with my car

Basically, was driving to my mates tonight, drove 10 miles absolutley fine. Had to stop to get petrol.
Left the petrol station, 2 minutes later the dash started beeping at me and the temp needle was just before 120.
Cut the engine and pulled over, the water was boiling in the header tank.
Left it for 10 mins to get the rest of the way (2 miles) and it was constantly over the 90 mark.

It came completley out the blue, I was driving normally (not puting my foot down).

I put the blowers on full to try and take some heat from the engine but they were blowing stone cold.

Im thinking it could be the thermostat?
Heard stuff about metal water pump impellors also?

What would it most likley be?

Thanks for your help!
Really need this one, just shelled out over a grand on bodywork and 3 days later it dose this to me

 

[sparkie1984]

probably thermostat mate, my water pump when it was changed had only one impellor fin left!!! crappy plastic shite! whats your mileage? when was it last done?

also do your fans work? do a search for fans not working and itll tell you about the melted fuse box problem

hope that helps

 

[karls cupra]

sparkie beat me 2 it was going to say check the fuse on top of the batt big green one i think normaly melt ..

 

[sparkie1984]

only thing with that is, the heater would still blow hot. but it may be a culmination of problems maybe fans and stat

 

[s1l3nc3r]

thermostat, water pump as above check the fuse mate...happend to somone i no they were sitting in traffic all of a sudden water going everywhere needed whole new fuse box...

 

[karls cupra]

few months after i got my car this happen sittin in traffic and temp gauge went right up had to pull over to let cool down and presure of it put a hole in my rad as well but took to garage to change rad and they as found out fuse melted and thats why it over heated cause had no fans ...

 

[AlexGSi2000]

Cheers for the replys!

Iv checked the fuses on the bat and fusebox, they all seem to be ok.

The fans do work, just dont blow hot.

Tried bleeding the system, but it just boiled over when it got hot.

The previous owner had the belt changed at 55k (now just on 70k), dont know If he had the pump changed aswell, im going to ask and find out.

All the pipes from the thermostat seem to be getting hot.

 

[AlexGSi2000]

Just a quick one... is the waterpump driven by the Cam or aux belt?

Going to take off the thermostat in a sec..

Cheers.

 

[peter_cupra197]

Just a quick one... is the waterpump driven by the Cam or aux belt?

Going to take off the thermostat in a sec..

Cheers.

cambelt drives it mate, possible head gasket issue.

 

[fudd]

Best get a garage to pop a machine on the coolant and see if there are any combustion gases in the coolant that will rule out the headgasket and let you move on to other things

 

[Boo]

Check the thermostat housing too as this has a tendancy to crack.

 

[footlong]

Overheating and cold air from the blowers is usually a good way of spotting a shagged head gasket. i hope it's something less major, but if it was me, i wouldn't hold my breath.

 

[ian_cupra]

its the water pump, especially if the previous owner didnt change it, mine went at 52k, they just crack and break down.

you wont get any hot air through the fans either, due to the pump not pushing the coolant round to the heater matrix, my money is on water pump!

best bet is to just take it out and have a look, means getting a new cam belt etc... but worth it. check compression too though, as the over heat could have caused the head gasket to blow. hopefully not as mine didnt and it went well over 120 degs

but it defo sounds like water pump

 

[cupraajy]

Just a quick one... is the waterpump driven by the Cam or aux belt?

Going to take off the thermostat in a sec..

Cheers.

Im having the same probs with my mk4 cupra at the moment! changing the thermo tonight, so fingers crossed this will fix the problem! When the AA recovered me he ruled out the water pump cause there was a steady flow going through the coolant resvoir! would u see a failure of a head gasket at 38K miles?!

Sorry for the hi-jack! just needto get as much info as poss before i start diggin bout the engine!

 

[ian_cupra]

Im having the same probs with my mk4 cupra at the moment! changing the thermo tonight, so fingers crossed this will fix the problem! When the AA recovered me he ruled out the water pump cause there was a steady flow going through the coolant resvoir! would u see a failure of a head gasket at 38K miles?!

Sorry for the hi-jack! just needto get as much info as poss before i start diggin bout the engine!

the secondary water pump, can still give a flow into the coolant resivour, so i dont see how that can rule out the water pump. i've had the same problem as both of you, mine was the water pump

 

[cupraajy]

the secondary water pump, can still give a flow into the coolant resivour, so i dont see how that can rule out the water pump. i've had the same problem as both of you, mine was the water pump

Ok then...thanks for that! what parts etc will i need to replace the water pump? going to the dealers today to pick up the thermo, so will price up the parts while im there

 

[ian_cupra]

you'll need a cambelt kit, including tensioner, and metal impellar water pump.

you can check the compression in the engine before you start, as i dont want to be held responsible for telling you it is definately the water pump, but i had same trouble and mine was. its the most likely thing to brake in the system, bit i'm not sure what style water pump you mk4 guys have as i dont know if they changed to metal ones for the mk4, best checking with some of the other mk4 boys.

 

[cupraajy]

you'll need a cambelt kit, including tensioner, and metal impellar water pump.

you can check the compression in the engine before you start, as i dont want to be held responsible for telling you it is definately the water pump, but i had same trouble and mine was. its the most likely thing to brake in the system, bit i'm not sure what style water pump you mk4 guys have as i dont know if they changed to metal ones for the mk4, best checking with some of the other mk4 boys.

dont worry i wont be holding u responsible ha ha, it booked in for the belt and water pump anyway when it hit 40k.....might end up being sooner!!

Ive checked wit the mk4 boys, and the guys that have had the same symtoms (water pump failure) are running higher millage as me so there are a bit stumped and also point me towards the thermo! just wanted to get some more insight into it!

Thanks for ur help tho!

 

[AlexGSi2000]

Iv just booked mine into awesome gti, dropping it off this evening.

They recon its probably the waterpump and have quoted me 295 for the waterpump (with metal impeller) and cambelt change.

Could do without the aggro at the min but iv got no option! And I know its going to a specialist!

 

[ian_cupra]

cupraajy - no worries, i'm about 95% sure its the pump as they can just go at any time really. crap plastic things

alex - yeah like i said, yours is about 99% likely to be water pump if not 100%. £295 isnt bad price for the work, as parts alone are around £150 from stealers.

hope my previous experience has helped the 2 of you