Golf mk3 overheating

thesoulfulldude

my vw golf mk3 started overheating 2days ago, tought it was just the fan temp switch cause the fan wouldnt kick in over 90o

so replaced the Thermostat but it still runs to about 110....

could it be the water pump?? but there is no leak!

also the pipe going to the radiator is very hot but the pipe coming from is not.

any ideas? need to get this sorted quick i need it for work

Run_to_da_hills

It could be the head gasket :eek:

Check water level in the rad/expansion bottle and see if there is any bubbles rising. Also check the dip stick for a milky grey mix.

thesoulfulldude

Run_to_da_hills wrote: »

It could be the head gasket :eek:

Check water level in the rad/expansion bottle and see if there is any bubbles rising. Also check the dip stick for a milky grey mix.

i'll check right now if your still online..... the bottle lets alot of steem out and after the engine is off you can hear it bubbling, if you open it just blows casue its underpressure.... as for the dip i'll look now

thesoulfulldude

oil is fine its the right level and dark brown color.....

Gary ITR

I'd rule out all problems at the fan first before I'd start panicing and looking at the head gasket.

Is the car loosing water at all?

thesoulfulldude

no its not loosing water untill it over heats and expells water from the bottle ( it as a valve or something on the side that opens)

also i just realised the raidator does not get hot. the fan worked for a moment when i pluged the new switch back in but then stoped. also if i by pass the switch and put current to the fan it runs

thesoulfulldude

just turned the engine on there again, its only at 70 but the temp light is flashing.....

BrianD3

If the top hose gets hot the thermostat is probably opening OK. If the rad doesn't get hot it may be blocked or the water pump may not be circulating the coolant properly. Some VWs have a plastic water pump impeller which can break up, the pump bearings and seals may be fine in which case you won't get leaks out of the pump's weep hole.

Also if the fan switch is in the rad and the rad doesn't get hot, then the fan won't come on even if the switch is working properly. Bad coolant circulation could also affect the temperature gauge reading

thesoulfulldude

BrianD3 wrote: »

Some VWs have a plastic water pump impeller which can break up, the pump bearings and seals may be fine in which case you won't get leaks out of the pump's weep hole.

interesting, the problem is the water pump is connected to the timing belt so i dont want to go messing with that, i'll have to get a mechanic to look at the pump, just want to try everything else i can first to try save myself some money before i go down that road! but thanks for that

BrianD3

If you are looking for cheap things to do then you could flush out the rad with a hose, it may be cruddy and a flush should improve efficency. Even if the water pump is the main problem a more efficent rad will help a bit. Also if you are driving the car stick the heater on full blast and open all the windows, this will help with cooling.

peasant

You could also have air in your rad.

If you have more coolant ready for a refill, you could try bleeding your rad (if it has a bleed valve, that is ... on my yoke that's at the top, near the sensor for the fan)

Flyer1

If you still have problems post a question on www.vagdrivers.net They're all great lads who know -everything- about VW's.

thesoulfulldude

ok good news i hope, i took the thermostat out and now the car runs perfect the fan kicks in at 90o and the water is flowing fine. i must have been sold a faulty thermostat!!! i'll find out on monday when i go and get a new thermostat

thesoulfulldude

another problem, the pin in the thermostat when its heated it pushes out. does this pin need to push against something in order to operate? looks like there is a hold designed for it but mabe this hole has been punched out under pressure?????

ART6

thesoulfulldude wrote: »

another problem, the pin in the thermostat when its heated it pushes out. does this pin need to push against something in order to operate? looks like there is a hold designed for it but mabe this hole has been punched out under pressure?????

Not sure what you mean by a hole punched out, but you can be assured that it wouldn't be as a result of pressure -- you'd need a couple of tonnes of force to do that. Thermostats do fail, and the way to find out if yours has is to stick it in a saucepan of boiling water and look to see if it opens. If in doubt, change it anyway. The cost is peanuts compared with the cost of an engine rebuild.

RICARDO1982

does this pin need to push against something in order to operate? looks like there is a hold designed for it but mabe this hole has been punched out under pressure?????[/quote]

Yes it does. it presses against a stop in the part of the thermostat
housing that the radiator hose is attached to.( The flange you remove
to get the thermostat out.) This is most likely your problem
The plastic breaks off at the end of the hole and does not allow
the thermostat to open, then restricting flow..
This flange is not too expensive, However if you are hanging on
to the car a complete thermostat housing is a better bet as
it includes the coolant temperature sensor(another common fault)
and thermostat. It works out a better idea but it takes a bit longer
to fit.
I had a mk 3 golf for years let it go at 150,000mls its still
going strong not a bad car felt solid nice to drive but an animal
on the petrol

thesoulfulldude

thanks for that, yeah it looks like it needs to push against something be wasnt sure! i'll have to get that part 2morro

thesoulfulldude

RICARDO1982 wrote: »

does this pin need to push against something in order to operate? looks like there is a hold designed for it but mabe this hole has been punched out under pressure?????

Yes it does. it presses against a stop in the part of the thermostat
housing that the radiator hose is attached to.( The flange you remove
to get the thermostat out.) This is most likely your problem
The plastic breaks off at the end of the hole and does not allow
the thermostat to open, then restricting flow..
This flange is not too expensive, However if you are hanging on
to the car a complete thermostat housing is a better bet as
it includes the coolant temperature sensor(another common fault)
and thermostat. It works out a better idea but it takes a bit longer
to fit.
I had a mk 3 golf for years let it go at 150,000mls its still
going strong not a bad car felt solid nice to drive but an animal
on the petrol[/quote]



just to let you know this solved my problem thanks for the help, looks like it has melted away over time! but you can clearly see the hole compared to the new one! part only cost me 17euro to bad i had already spent 40 on the thermostat and fan sensor!

gavo782002

Hi i looking for some advice my ford fiesta has been leaking water the past few mouths from underneath the engine, this is causing me problems cos the car is blowing out cold air and overheating due to the water leak, I've had the water pump and the thermostat replaced could it be the gasket? or something less serious