Vr6 running hot!!!!

[bv-vr6 0]

Hi there guys this is my first post on the site, as i have previously admirred from afar lol!

Here is my problem; bought myself a 94' vr6 about 2month ago now, and i have been having problems with her running rather hot when in traffic! the water temp is rising up to 110oC!!!

 

ive had a few bits done to fix it but obviously it hasnt worked lol! had the thermostat changed this made it worse as the pressure in the system shot up. so put the old 1 back in again which is jammed half open/open (not 2 sure on that). had the water pump changed today but there was nothing wrong with this the mechanic has said so problem still persists.

i know that the temp will rise as there is no thermostat but putting it in again doesnt sound too good.

other than this love the car to bits, but this is really annoying me as i now hate being in traffic more than ever :x lol!

if anyone could give me any suggestion it would be much appreciated!!!

just hope its not the head gasket!!!!!!!!!!!!!

 

thought id add its not actually overheating as fans are kicking in and its not using much/if any water at all!!!!

wrote a bit more than expected but just hope to get to the bottom of it!!!

brian

[PhatVR6 0]

welcome to the forum

 

it's probably a case of the number 1 fan speed not working, as is oh so common with the VR6 fans.

 

turn the engine off when you're sat in traffic.

[bv-vr6 0]

both fans are working fine it seems. i popped the bonnet outside my house when i got home and waited for them to kick in to check and they both did!!!

thanks for the welcome!!

the turning off the engine aint to good when its slow rolling traffic tho lol

but thanks anyway!

[vr6storm 0]

they both will kick in anyway as they are connected.............its the different speeds Phat was speaking about

[PhatVR6 0]

yes, at what temperature do they come in?

[bv-vr6 0]

ok get ya!! yeah they both seem to kick in at the same speed. they come on fast then slow down, and they both seem to do the exact same thing!

thats the thing they kick on at 110oC!

im guessing this is too high? (sorry not too clued up)

its more the problem with what is causing it that i am trying to find out.

so hopin if i could get to the bottom of it that everything would maybe fix itself out hopefully!!!

[vr6storm 0]

yer temp guage isn't also the most accurate too btw..............i used to worry about mine creeping near 110 in traffic..........checked it out with VAG-COM and 110 on the guage corresponded with 98 on VAG-COM

[bv-vr6 0]

ok well that does make me feel a bit better about the situation :D lol!

that could be the case as the temp gauge never worked when i first bought the car! but the oil level wasnt that bad so took a risk lol!

 

got the thermostat housing changed, as thats what i was told was the problem by the seller! but wasnt then all the sensors, and finally they worked out it was the actual gauge so got an auto spark to have a look and he found that the contacts just needed cleaned!

so wonder what is next to go wrong? lol

 

so you dont think it is the head gasket then? as thats what a mechanic said things are pointing to! but he did say that there are others which make him think its not so i dont have a clue to be honest!

but thanks for your help guys

much appreciated

[dr_mat 0]

The fans are supposed to come on at about 88-92 degrees. If they don't there are three possibles:

 

- thermostat stuck closed (this means the temp sensor in the rad never "sees" the hot water)

 

- thermoswitch in the rad failed (it never turns the fans on despite the water being hot)

 

- fuse gone (there is a separate fuse for the low-speed fan operation compared to the uber-fan megaspeed that comes on at 105 degrees).

[bv-vr6 0]

so the only thing it could be in my case is that the fuse has gone then? as my thermostat is open and the fan is coming on!!

[PhatVR6 0]

or the first speed oft he fan isn't workin, like I said i the first place.....

 

in which case the fans are coming on at the second speed, can't remember the temp which that is meant to be.

[bv-vr6 0]

ok then thats great then! that looks like that will be the next thing to do!

sorry bout that PhatVR6 i just picked up what you said wrong!! me being a bit dumb lol! after reading what you said again i understood!!!

i will keep uz posted on the outcome

many thanks again!!!!!!

[PhatVR6 0]

as for them both doing the same thing, they will do, there's only one motor, the second fans runs off the first via a rubber belt.

 

if the left one doesn't turn with the right one, the belt has snapped.

[dr_mat 0]

it's the thermoswitch that controls the first and second speeds, so if the "first speed isn't coming on" - which I'm sure you're right about, by the way - it means it's the thermoswitch that's faulty..

[bv-vr6 0]

ok no prob ill get myself a new thermoswitch thenand c if that fixes it! heres hoping!!! lol

PhatVR6 it was just the way i understood your message i was thinkin you meant the first and second fan not the first and second speeds, but i get ya now! lol

cheers guys

[big_chris1981 0]

the first speed of the fan doesnt seem to come on, on mine either.

 

dont suppose anyone knows the part number?

 

(and would care to share? :D)

[Storm Warning 0]

I was just checking my fans and they are behaving oddly! at about 100-105 the fans came on, fairly quickly...enough to feel hot air flow near the car. The came on for a few seconds..then stopped. A minute later the same again..then again a few minutes after that. in that time the temp maybe got to 105..+- 2deg.

 

So I stopped the engine, the fans came on and stayed on for a minute or so. Much confusion! Going to go and check the fuses in later on.

 

Any advice welcomed..

[fla 9]

Where would you wire the fans to check fan operation at each of the three speeds directly ie without waiting for the temp to rise and the fans being switched on via the thermo switch?

[Kevin Bacon 5]

Just to clear up the cooling system anomilies....

 

Fan 1 - Direct to battery - comes on at 90 degrees.

 

Fan 2 - Controlled by the big box (Fan controller) in front of the water tank - 100 deg.

 

Fan 3 - Ditto - 120 deg.

 

The controller stays on for 10 minutes after you switch the car off (regardless of temperature) and maintains power to the secondary pump and fans.

With the car off, you should hear the pump whirring and if hot enough, speed 1 will be working too and possibly speed 2 if it's really hot and bothered.

For non-aircon cars, speed 3 should never come on under normal conditions, if it does, you have a problem.

 

It's engineering gone crazy. All VW needed to do was slot a couple of SPAL fans on the rad that come on at 90 degrees and that's it, really no need for the above nonsense!

 

Speed 3 is actually the effective one though and worth using an override switch on the dash (black temp sender in stat housing) to trigger it manually if the temp guage's position is bothering you. You can also rig up speeds 2 *and* 3 if you like with a 2 way switch as Speed 2 is a low current trigger also.

Just don't overide Speed 1 without a relay or you will set your dash on fire :-)

 

Don't get too obsessed with temps anyway folks, what the guage is telling you and what the head temperature is are very different. I think most of you would cack yourselves if you knew how hot the head runs, especially the rear bank.

 

All you need to know is the guage is at, or just below half on the guage. i.e. perfectly normal. It's where Golfs used to sit. It's purely because VW put temps on the guage that people panic, they're innaccurate markings anyway, just like the fuel guage!

[Storm Warning 0]

kevHaywire thanks for that, all clear now. Even if the temp gauge is well out I think I should have seen the consistant Fan 1 as it had been running on my drive a long time. but all I got was it cutting in and out... not sure what speed at though. oh well, at the moment the needle doesn't got too high so I guess I shouldn't worry...maybe another day when I get more time.

[fla 9]

Just on the topic of cutting in and out, when my fans trip in the diverter flap by the air intake vent closes and there is a slight jolt as if a high current unit is coming on line. Mine has aircon so i dont know if thats got anything to do with it? What is the normal situation? Most cooling fan setups I've seen just come on and off quite unobtrusively, you just hear that notorious whine...

[Kevin Bacon 5]

Storm Warning, if the fan was coming on and off, sounds like it was just regulating the temperature. If it switches on/off with a set pattern, maybe the sender in the radiator could do with replacing as it senses the temp for speeds 1 and 2. Might be an idea to change it anyway tbh. A git to get to, but worth it for peace of mind.

 

My cooling system is spot on, never goes over half way on the guage and the fans rarely ever come on, but all 3 speeds work, so I guess the engine is happy enough to not need them the majority of the time. I've got a couple of slimline fans to go on, which will just run off the speed 1 trigger. Everything else will be redundant as it's overkill imo.

 

fla, I believe speed 3 is used in conjunction with the A/C but not permanently, so your car might sound like a hovercraft from time to time, which is basically how loud speed 3 is!

 

Sat in traffic for an hour today and did a test. I let the water get to 100 and the oil to 96, which are fine anyway, then hit the speed 3 switch. Within 30 seconds, the water had dropped to just above 70 and the oil fell to 82 :-) It works!

[bv-vr6 0]

Rite guys i changed the thermo swith and got a new temp sensor for the radiator, but still kicks up to 110oC in traffic!

the fan still does not come on until 110 either. any more ideas of what could be the problem?

[Kevin Bacon 5]

OK....try this....

 

1. Take the plug off the rad sender

2. Take the plug off the black temp sender in the stat housing.

3. Switch ignition on.

 

In the rad sensor plug - red wire is speed 1, thin red/black is speed 2. The other wire is the common connection. Bridge each of the two wires in turn across the common wire and see if both speeds come on. If they do, good.

 

4. Bridge the black plug with a paper clip or something, does it come on? Sounds uber loud!

 

So that's the fan test done. Tick it off as outruled.

 

5. With the ignition on, can you hear the electric water pump? You should do.

 

Failing all of the above, I suspect you might have an airlock in the cooling system and the only cure is a drain and refill, but fill via the radiator top hose and not the expansion tank.

 

Use only G12+ from the dealer. Mixing G12 with G11 causes solidifying of the glycol and will block water ways.

 

If not that, the radiator might be blocked and will need a thorough flush at best, or replacement at worse.

 

If speed 2 and 3 don't work, the controller is dead. £110+VAT!!

[fla 9]

kevHaywire, thanks for that. The diverter moves every time the fan kicks in ie even at 96 oil. HAving a blast on the motorway brings it up to about 116C but no higher, but its difficult to hear whether speed 3 is on or not. How would you wire a switch for speed 3 anyway - i like the sound of that one!! Prob better than having a mocal even!