95 VR running at 105 degrees in traffic

[davebirl 0]

Sorry for my first post to be a problem but here goes...

95 Corrado 2.9VR6, New water pump, Samco hoses, timing chains and thermostat 8 months ago. all was good.

Now car runs at 105 degrees before fans kick when in traffic. When driving at 60mph it will fall and rise from 90 to 100. Oil temp is 112 to 116 when at 60mph, 105 when in traffic.

I have replaced the yellow temp sensor and oil temp sensor and all is the same. replaced temp gauge and the same.

Lower hose on rad is hot but not as hot as the top hose. The electric AUX pump is noiser than it used to be but there is still circulation and no leaks at all. could the aux pump cause this overheating?

Have checked oil and its clean. no hydro carbons in water either. my vw mechanic says its not headgasket. I had flushed the system with new coolant when i done the timing chains and there is no gunk in it.

could my 8 month old thermostat be knackered? or could it be aux pump? my rad is clean too by the way or at least it seems to be. should the fans kick in earlier than 105 degrees?

Thanks,

Dave

[Ciaran 4]

what thermostat did u get cos it's preset setting should be lower than that.

the top hose will be warmer as heat rises mate.

would not imagine the pump would cause this more likely poor circulation of some sort!!

[davebirl 0]

I got the original 80 Degree C thermostat from VW. Going to change Aux pump this week and then new thermostat. I have ordered the 71 Degree one from awesome already.

[FishWick 21]

Aren't you on the Corrado forum? Recognise the name.

Anyway, before splashing out on sensors, guages, thermostats etc lets look at the basics....

1) Air lock - Have you drained and refilled via the rad top hose to ensure there are no air locks?

2) Are the fans working properly, all 3 speeds? It could be that the 1st speed isn't working as it's quite subtle.

Mine used to run at similar temps and the only cure was an Mocal oil cooler and a full coolant flush and new rad temp sender. Now it rarely goes over 90 on the oil.

I would wire in the 3rd fan speed if you're concerned about traffic temps. Bridge the black sender and run a switch to the dash. I have a 3rd speed override on my dash and it's handy to have when things get really hot. It sounds like a hovercraft when that kicks in!

[davebirl 0]

Thanks Kevhaywire

Yes I am on the Corrado forum too but didn't get any extra info on my problem so I thought i'd post here for a wider variery of Vr6 users.

as regards the rad temp sensor, what does that one do? I thought the yellow sensor on the termostat housing was for the first 2 fan speeds?

I did bridge the black one and I did get the hovercraft effect but that one never kicks in....as it never reads higher that 105 anyway.

is there a way to test the two speeds from the yellow sensor?

I also got the lend of the big relay module for the fans from a mates VR6 that has the engine out for work and I still only get the standard fan speed, at least i think it is cos I've never got any other speed.

Is it very important to fill via the top rad hose and not the resevoir? We filled through the resevoir when I flushed with the chains job etc.

Thanks

Dave B

[just2zang 0]

i had the same trouble on my vr6, changed fan and water thermostat with neuspeed items as they were quite cheap. The car ran sweet as a nut.. Be careful with the thermostat housing as these tend to crack or leak. Any signs of leakage then get a new one.. seen loads on ebay. Always be careful with low oil levels and also the headgasket when you have overheating problems.

[nealster1972 0]

Hello mate, whilst i pretend to know F all about mechanics of my VR6, I am a corgi reg. plumbing and heating engineer.

Its the bit where you said about one hose being hot and the other end of the rad being cold. Just maybe there is a blockage in the rad. If rads in houses can block up then why not a car. ?!

going back under my rock now :?

Justin

[davebirl 0]

ok peeps heres the low down so far. drained coolant again. no dirt or crude to be found. removed aux water pump and hey ho, no bloody rotors in there........gone.......disintegrated! split pump apart and rotors are missing in action from inside the aux pump! replaced pump with second hand one and refilled coolant. had to get rid of a wee airlock from the heater matrix but that was no trouble. let car run up to temp and tested all 3 fan speeds ok. both top and lower rad hoses warm but still seeing 105 degrees when idling. now please bear in mind this was Saturday and I only received the new thermostat this morning so I will be fitted new thermostat sometime this week. Do you guys reckon those small wee rotors from the aux pump could be messing with my rad or thermostat? Also my new thermostat is the 71 degree one from Awesome. i did not find any bits of the aux pump in the coolant drain and I did drain from the lower Rad hose too.

[magentaham 0]

Is your main waterpump a VW origional?? You know the one...with the mica impellers that break off 1, 2, or the whole impeller, or is it an aferthefact with a steel impeller??

[davebirl 0]

@ottobomb

My main waterpump is a brand new VW one (fitted 8 months ago) with the plastic impellers. I know what you're thinking and I'm hoping the new thermostat with sort out my temp problem but I might just pop out that pump too to make sure none of the impellers are broken because of the Aux pump failure.

[davebirl 0]

Yipee! After fitting the new thermostat, ie the 71 degree version from Awesome GTI my VR6 now runs at 75 to 80 degrees wen driving and oil temp is 96 to 100 degrees!