Overcooling

[seanl82 23]

Hi chaps, have a problem which I'm not sure what else to try. My water temp never seems to get over 80 whilst driving. If sat at idle, it will get to 90-95 eventually, but never whilst rolling. Oil temps never get above 106 so think the pump is ok, and I've changed matrix, coolant, thermostat (did the boil test with both new and old one, and both operated correctly). I know it's a little chilly, but it takes quite a while to get to 80 too. Fan operates as it should somewhere in the region of 95 degs when at idle, but rarely notice it on after a drive so it's not constantly going or anything. Anything else I may have overlooked? Any help appreciated. Oh it's a KR, thanks guys.

[m4ttj4mes 10]

hi pal, havent really got much advice to give except to let you know mines about the same! on the motorway; water sits at about 80 (line under the middle one) and can get up to the line above middle (100) in traffic, and oil temp is usually 88/90 whilst driving (motorway - towns different mind...) and i to have seen 106 max. ive also changed a large amount of this which would affect these temps and it runs the same as it did before really, just have peace of mind now!

[Purple Tom 0]

Have you tried a new temperature sender?

 

Not sure if the K-Jet operates in the same way (slightly inexperienced with them) but with Digifant there's a temperature sender for the ECU and a seperate one for the gauge. It's possible that the temperature sender has become faulty and is sending an incorrect voltage to the gauge.

[Stonejag 10]

Could be your thermostat's stuck open? My VR does exactly what you describe...

[seanl82 23]

Could be your thermostat's stuck open? My VR does exactly what you describe...

 

As said, I've changed the stat and whilst old one was out, I tested them both together in a pan of water on the hob. Both opened as they should, then closed when taken out and left to cool. Maybe worth changing sender, will give that a go first, but still takes a while for heaters to get warm anyways. (bearing in mind the foam is almost non existent now in channels from changing the matrix), but still doesn't seem quite right. Oh I've swapped out bypass valves for copper pipe too if that makes a difference?.

[Wild-Animal 0]

There are three senders on the end of the engine block, below the dizzy. All there of these are the same so you can swap the wires about and one of these are for your water temperature. What you might find is swapping them about might give you slightly different readings. I noticed when I swap mine about is the temperature needle does seem to sit differently.

 

Also I take it your car is running fine? I got my CO set up right and that made a big difference to the engine temperature.

[RW1 0]

Don't think its a temp sender. As seanl82 has said, he feels its cool as well through the heater for too long. That points to the thermostat. For what it costs, despite it appearing to work OK, I'd change it out again for another new one.

 

.

[seanl82 23]

It does point to stat as far as I can tell tbh. Just strange that both were the same when testing, and were more likely lazy than completely shot as they did both close. Only did it last week too! Oh well, will try another new one. Will give the sender wire a swap round out of curiosity also though. Thanks for all the replies fellas, didn't know if I was having a brain fart and missing something!

[owen g60 10]

Do you have a after market oil cooler as this will bring all temps down a fair amount

 

 

Sent from my iPhone using Tapatalk

[seanl82 23]

No, original standard one as far as I can tell.

[RW1 0]

It does point to stat as far as I can tell tbh. Just strange that both were the same when testing, and were more likely lazy than completely shot as they did both close. Only did it last week too! Oh well, will try another new one. Will give the sender wire a swap round out of curiosity also though. Thanks for all the replies fellas, didn't know if I was having a brain fart and missing something!

 

The reason I say what I posted (thermostat) is because your other temp & sensors (oil temps & rad fan switch) are reading/triggering what they should and presumably you are using the dash water temp gauge for the coolant readings of the fan triggering, so the dash sensor is working.

 

The only other quick check I would do is carefully undo the header tank very slowly when warm and check there is a pressure build up. Careful, if you go too far, it will spill over the outside, so only enough to make sure it hisses and retighten. If it doesn't, renew the header tank cap.

 

.

[seanl82 23]

Good shout with header tank! It's the original black one as well so worth changing to the newer blue one. I've heard them not releasing pressure, but I guess that it could be constantly venting too which could cause lower temps with the system not being pressurised fully.

[gurby28 10]

Hi,

 

Any update on this?

I'm having exactly the same issue with my '94 black VR6. Renewed thermostat (+ housing) twice, a new blue header tank cover is placed. All without effect.

Please help?

[24V Renshaw 0]

Are you rad fans on a lot?

 

Jay

[Wendy 0]

I have had all the above done - at Stealth - still reading same - just over 80 degrees.

 

With old thermostat was about 75 ?? !!!

 

Am assured by Stealth boys this is fine !

 

---------- Post added at 9:56 PM ---------- Previous post was at 9:56 PM ----------

 

No - rad fan not on alot.

[VeenixTwin 10]

So its not just me then.:bonk:

 

Had a '96 VR with the same problem. Gauge always indicating running low temperature but with oil temp ok. Was like it for years and was still the same after a top end rebuild after the head gasket went. All cooling parts replaced at same time.

 

Now running a 95 VR Storm and its doing the same!!

 

Both cars fans were kicking in fine to cool 'em in traffic, after the gauge went up to 95*c.

Ive also ran 3 Golf VR6s and the gauges in these went up to 90*c then never moved all day!

 

Puzzling.

[gurby28 10]

@VeenixTwin: also replaced the 3 sensors in thermosthouse and the switch in de radiator?

 

@24V Renshaw: no fans ‘looks like’ it’s working fine. However, before winterstop, when my car always ran on 90 degree, the after-run fan was always starting up, running for 6 seconds, stopped. Then 10 seconds later again and again and again… could that be an indication for anything?

 

Before the winterstop my Corrado also ran always on 90 degree, that’s why I ‘m not content with the current situation…

 

Is there any change that all 4 sensors (3 in thermostathouse and 1 in radidator) are weared and rubbish over the years and now ‘switch’ at higher temps then what they are specced/required to do?

 

So….

 

- my water is – at drive - actually 90 but gauge is showing 75 due to the delay in the gauge temp sensors

 

- And when is is actually 105 – but gauge is showing 90 – then the fan is coming in due to the delay in the radiator temp switch

 

- For the ecu sensor nothing visible but maybe switching too late to the status ‘engine warm’ for other fuel injection?

 

Is this theory possible? Could be tested by renewing just 1 of the sensors (the gauge one for instance) isn’t it?

 

By the way, heater is working fine, also on the highway with 75 degree on the gauge.

 

My coolant was really rubbish when it came off the car. I flushed the system (Wynn’s cooling flush) and put new G12+ in.

 

Hope to hear your responses.

Regards gurby

[VeenixTwin 10]

@VeenixTwin: also replaced the 3 sensors in thermosthouse and the switch in de radiator?

 

The switch in the rad was changed, as a new rad was fitted when the head was off. Never got round to changing the 3 thermo sensors, as not long after it was back on the road the 96 VR was wrote off.

At present I haven't changed anything on the Storm.

 

Can anyone clarify exactly what a Corrado VR6 gauge should do?? Is it the same as all my golf VR's I had, when those engines were fully warmed up the needle sat in the middle and never moved regardless if it was sat in traffic, at 30mph, at100mph etc etc.......

[seanl82 23]

Still the same here. I replaced the Stat and flushed and replaced coolant with G12++ but still no different. Had a few more pressing problems of late, I may change the stat again though to be sure, as its an ECP one. One of the more pressing problems being that I replaced rear bearings with ECP ones on Thursday. One only lasted from work to home before disintigrating with the outer race welding itself to the hub! Sorted now, but there is some scoring on the hub, and I have the MOT tomorrow. Obviously I'm a little dubious of the quality from ECP now! I go to the stealer for most things, and bearings are added to the list now, even at near £50 a side!

[floppyman 0]

On newer cars (maybe mk3 vr6s) the temp gauge is controlled by the ecu, thats why it stays ,allways, in the middle. On the corrados they have separate sensors just for the gauge. On mine its the same as yours. But you can allways cross check it with the ecu temp readings with vag-com.

[VeenixTwin 10]

On newer cars (maybe mk3 vr6s) the temp gauge is controlled by the ecu, thats why it stays ,allways, in the middle. On the corrados they have separate sensors just for the gaugeQUOTE]

 

Cheers for the response. Suppose the main thing is it dosen't overheat!!

[Stonejag 10]

It's worth checking your fluid levels often - mine was underreading for ages and then I found a (very) slow hose leak that only seeped a bit when it was under pressure. Now of course it's spraying the lot all over the floor at the end of every trip! While my temporary repair was still holding (it's in quite an awkward spot to get to...) it pressurised a lot faster and I saw more realistic temperatures on the gauge. As long as you keep an eye on the oil temp in the MFA you shouldn't get caught out. The 'coolant low' light doesn't flash until the expansion tank is completely empty (plus a bit) so it doesn't give you a lot of warning.

 

Oh, and some of the hoses have gone obsolete now, so look after them!

 

Stone