VR6 Fan Switch Questions

[pommy_golfer]

Hi All,

I just noticed a problem with the VR, i have overheating probs and was going to change ther thermostat and the fan switch this weekend. However, on saturday, i took her out for a 20 minute drive and when i got back the temp kept on going up, as soon as i turned the car off the fan kicked in, when i put on the ignition the fan turned off? Would this be a dodgy fan switch or would this be a more complicated electrical problem?

I have been trying all day to get the fan switch off but nothing i use will get it off, ive tried pliers, adjustable spanner, 30mm spanner etc, i even went and spent 25 bucks on a 30mm spanner which looked huge, but even then i cannot get to it. The problem in its in a tight corner and is inset into the radiator housing which is a B******D to get too. I was going to get a socket and ratchet to do the job but the socket is too short and doesnt work either. Has anyone changed theres before and if so what and how on earth did you do it?

Any advice would be great at this moment in time....

[peedman]

I know that the late model golfs i.e. post 95, their fan will remain on after the car has been turned off. If u think about it when the car is running, the water is being circulated by the water pump. So when ur car off the engine actually gets hotter rather than cooler straight away.

If it never turns on when ur driving then theres something definately wrong.

[syncro]

All Golf fans work when the ignition is off. Your fan switch is probably OK.

[peedman]

Really? Coz mine never does it. :?

[bsting]

The fan in my 16v starts up about 5mins after the car is stopped and runs for about 5mins.
Its normal for them to do this. It has the same radiator as the vr6.

When was the last time you did a flush?

[monkeysrus]

Have you changed the mech water pump? Maybe it is not pumping right?

My fan runs after stopping, as does the elec water pump. The fans will also run when the car gets hot running. Have you scanned the car?

I changed the mech, elec, thermo and all piping at once and my car has run much cooler since.:D

[pommy_golfer]

how do you know if the water pump is not working? All i know id that when im driving the temp is ok, once i stop in traffic the temp just keeps rising and rising and it wont cool down? im thinking the fan isnt kicking in when it should..what else could it be???

[BlackVr6ix]

check your fuses and relays, my fan relay had melted pretty badly. cant remember 100% which one it was.

[evorobin]

I just had a fan relay melt. Replaced it and all is right with the world.

[pommy_golfer]

was your VR overheating when that happened? anyone else know which relay i should be checking?

[syncro]

What happens when you turn the air con on?

[bsting]

A mate here who has a vr6 had a similar problem to how you are describing.
Found out the waterpump impeller had broken off :o

He fitted a new waterpump its all good now.

[WA Euro]

here's a way you can check if your water pump is working.

Start your car cold with header tank cap off. Coolant should be pumping out of the return hose (top one) if the pump us pumping. You may have to increase the revs slightly to notice it though.

As for the fan coming on after switch off - from my understanding of VR's, when you switch your engine off, the elec pump keeps the coolant circulating and the fan runs to cool the circulating coolant. Genius.

If your gauge is going above 90ish and your fans aren't coming on, this would suggest thermostat not opening or water pump inoperative. Give your top radiator hose a feel when the temp starts to rise above normal. If it's cool enough to hold on to without burning yourself, then chances are, your coolant isn't circulating properly and this is why your fans aren't coming on.

Your engine temp measurement for the temp gauge is taken from a sensor on the engine - so if the gauge is high and no fans, the hot coolant is not getting to the thermo switch on the rad.

On a more serious note though - this problem may well be linked to your choc mousse. If you have oil mixing in your coolant, this could be an indicator of poss head gasket problem. Don't want to worry you, but it's worth thinking about if water pump and thermostat check out ok!

Hope i haven't gone on too long there

Steve-o

[h100vw]

On a more serious note though - this problem may well be linked to your choc mousse. If you have oil mixing in your coolant, this could be an indicator of poss head gasket problem.


A cheaper thing to check before pulling the head off if you have oil and water mixed, is the heat exchanger on the block. They can corrode through and cause the same symptoms as a duff gasket but cost a fraction of the money to sort out.

Gavin

[Bora Sport]

Well spotted and a good tip. A very likely scenario however if it has gotten too hot because the fans aren't coming on it could still mean bigger problems.

[syncro]

The fans have no relationship to the ignition switch.

The oil cooler is a known problem, especially if you don't use G11/12/12+ coolant.

[WA Euro]

Think you're right there, but my understanding of the VR6 is that when you switch the engine off, the elec water pump kicks in and if the mech water pump had failed colder coolant would still be in the rad. Elec pump would circulate the hot coolant round to the rad - and switch on the fans??

[pommy_golfer]

All good guys,

I found the perfect tool for the job, will take a pic of it and post it, it cost me only 10 bucks from bunnings and worked like a dream.

The fans kick in when the temp gets to 100 degrees. Is that the way it should be?

its not overheating now anyway so me happy!