VR running too hot (fan?)

[Jonny_L 0]

Hello again. I've just finished searching about this, but i'm completely confused!

 

As the title suggests, my new engine is running hot. Water temp was at 110, and oil temp was at 116 at one point. The fan's not coming on at all, so that'll be the problem i should think.

 

I've done the fan wiring test, with bridging the wires on the rad sensor and also on the stat housing, and it only works on the first fan speed for a start, not the second or third. Does this mean that the fan speed controller's officially mullered?

From what i've read, the 1st speed isn't on the controller, so I assume something else isn't right?

I can't hear the electric water pump when the ignition's on if that's supposed to be on too.

 

Only other thing i can think is that i forgot to plug something back in somewhere, or plugged it in the wrong place, tho i'm about 99.9% certain that i did it right!

 

Cheers, Jonny

[2corrados 0]

HI

Be very careful, the idiot local garage to me put the wrong 4 pin temp sensor in and boiled me. Use the genuine sensor from VW, about £26. Mine was having same problems, running 110 water . OK now tho. Should sort out aux pump too, it's all linked.

[Jonny_L 0]

Which sensor is that? On the stat housing?

 

If it's any extra help, the fan doesn't run on after the engine's turned off, and i've got a funny feeling the old engine used to be the same (with a different stat, housing and sensors). I remember the last time i actually heard the fan at all was when it ran on in the winter after a short drive, and i thought "why should that be on now".

Course, the old engine didn't get that hot or i'd of noticed it.

I'm wondering if it's the temp sensor on the rad maybe? Also, since the new block was sitting around for a couple of months, could the thermostat be at fault?

Any other checks i can do to test the fan speed controller too, since they're bloody pricey!

Cheers, Jonny

[2corrados 0]

yeah on the thermostat housing, bank of 3 on on the left looking from the front. 10 min job to change. thermostat might be dodgy if it's been stood, but changing it is a git as you have to take out the housing......or I did anyway. Plug it into a vag com and that might give you an idea. most good garages will do that for very little money, and it saves guessing

the auxiliary fan should run on after ignition turned off, but you would need to be right next to it to hear it. this apparently stops pooling of coolant around the engine, and subsequent damage.

hope that helps

Dic

[Andy T 0]

HI

Be very careful, the idiot local garage to me put the wrong 4 pin temp sensor in and boiled me. Use the genuine sensor from VW, about £26. Mine was having same problems, running 110 water . OK now tho. Should sort out aux pump too, it's all linked.

 

I fitted a new 4-pin temp sensor (from GSF, black with yellow band, which they assured me was correct for a '95 VR6) yesterday while I was fitting a VAG blue temp sensor, now my water temp is up to 110 deg. in traffic and the fans don't seem to be coming on at all.

 

I thought it just controlled the aux. water pump and fan run-on, so why would it affect the fan while the engine is running?

 

Wish I'd bought both from VAG now!

[Jonny_L 0]

Ah the world of cooling headaches. Fingers crossed, mines sorted now. I've had a lot on my plate at the moment so haven't got round to doing it. I booked it into the garage today and they replaced the rad fan switch. now, touching wood here, it was running ok this morning, water temp was between 90 and 110 all the time, but the oil temp was still up around 112 degrees. this is about 10 degrees hotter than my old engine, but does that still qualify as "normal" running temp, or is that too hot?

[2corrados 0]

the 110 degree was the same as mine after idiot put in wrong one. have since changed it, but not had car runnign again yet as having rebore etc.

It does sound too hot, but i'm not an expert here, only passing on what I have experienced. Try the genuine from vag and see if it's any better. then take the other back and argue like buggery.

Dic

[catch_twotwo 0]

It should sit mid gauge according to people I've spoken to.... anything above is hotter than normal. Mine sits about 90 now I've fixed it.

 

Things I checked / replaced .:

 

Blue & Black temp senders (even if the sender to the dash is correct the other might be playing up)

 

If the fan doesn't kick in at low speed when you're temp hits 90° then it could be the thermostat on the radiator where the fan plugs in. Short the plugs on the fan plus (not the sensor on the rad) 1 & 3 and 1 & 2 should be the high and low settings. just can't remember which is which) If neither work then your fan is shot.

 

If the fan kicks in but doesn't cool anything then the rad termostat might be stuck closed. Check the top and bottom hoses (carefully they'll be hot) if the bottom is cold then the rad is doing nothing as the thermostat is shut, or there's an airlock in the system.

 

I ended up changing everything in mine all over a few days and mines working fine now..... usually if the temp is high you'll see other things failing. It blew my Heater Matrix, so don't run it if you don't need to... save yourself the extra trouble.

[markievw 0]

What should the corrado vr6 oil temp be? My car runs at 112 on motorway. But water temp gauge never goes above halfway. One thing I have noticed is that the fan only comes on when i take the key out of the igntion? any idea?

sorry to hijack you thread!!

[Jonny_L 0]

No worries! it's good to know that i'm not the only one. so water temp for me is about fine too. Hmmm... the plot thickens. I'm gonna run it at standstill tomorrow with vagcom plugged in to make sure that the fan comes on at the right time (if at all!)

Is it possible that the cooling system's not to blame after all if the water temps ok?

This car's had cooling problems since the day I bought it! first a blown hose, then the stat went, for a while it was fine, but now with the new engine it's giving me jip again. Maybe I should've stuck to aircooled VWs!

[Andy T 0]

What should the corrado vr6 oil temp be? My car runs at 112 on motorway. But water temp gauge never goes above halfway. One thing I have noticed is that the fan only comes on when i take the key out of the igntion? any idea?

sorry to hijack you thread!!

 

The thermoswitch in the rad has probably give up, I've found my fan only comes on at the second stage (around 105°) so i'll be changing mine this weekend, they are easy to replace.

[Jonny_L 0]

I just went for a drive, and it turns out my fan is coming on after all. The water temp was a bit on the high side, around 110, and oil temp was at one point 116 degrees again! Oh dear.

 

Anyway, I went straight back to the garage (the guy working there's an old mate of mine).

The fan wasn't working before, but is now so he did half of the work, but he said that I should try swapping all the sensors over from my old engine. I figure it'll cost me nothing to try, so I'll do that soon.

 

It's so nice to actually drive the corrado again! This is the first day i've taken it more than 10 miles in about 3 months, and i've been driving a crappy rover 25 all that time. I know it doesn't work properly yet, but i'm still smiling anyway :)

[Andy T 0]

You'd be best getting buying new rad thermoswitch & yellow temp sensor rather than putting in old ones that could be faulty or getting past it, then you can eliminate those bits if it still doesn't work. Not much fun changing sensors if you have to do it all over again!

 

Forgot to mention, if anyone wondered, the sensors in the VR6 stat housing can be changed without losing much coolant if your quick, but if you let the coolant drain out from the housing, you'll need about 3 litres of coolant/water mix to top it back up again.

[dr_mat 0]

Oil at 116 is not that unusual, but water at anything over 100 is very unusual.

[Jonny_L 0]

Ok, i've just about had it with this :mad:

I put all 3 sensors from the old engine's stat housing in the new one. Just took it for a spin, and it's exactly the same. the oil tended to stick at 116, went to 118 when i gave it some welly, though didn't seem to climb any more. Water stuck around 110.

To top it off, I think I just heard a little whistle coming from a hose at the back of the block. Also, the fan wasn't on when the water hit 110, and didn't run on after switching off, but it was on when it was reading about 100 degrees earlier. I'm still thinking fan controller module, but I don't know why it should need anything more than 2nd stage in this weather anyway.

Unless the old sensors have had it too by now of course.

 

One thing that keeps niggling at my mind... I put a light coat of high temp paint on some parts of the block. Thinking about it, maybe that couldn't of helped the temperatures.

Otherwise i'll have to get an oil cooler maybe.

 

Any other ideas

[Andy T 0]

Mine is reading water temps of 100 at 70mph on the m'way, and 110 in traffic. I'm thinking that the sensor is inaccurate and giving high readings, i'm sure before changing the yellow sensor I was getting 90 deg. at 70 mph, maybe this is part of your problem.

 

Can't see engine paint affecting temperatures that much if at all. What was the stat like in the housing you swopped over, does it open fully?

[Jonny_L 0]

I was hoping it might be something like that, but to open the bonnet it feels like there's too much heat coming off it still. That hose might be showing signs of stress maybe too, but I remember it was the one hose that I looked at and thought it'd need doing soon.

Those sensors had been sitting around in the open stat housing for a couple of months so maybe they're dead too, since it didn't seem to make any difference at all.

I didn't actually change the stat or housing, so perhaps that's my next port of call? The one on the old engine is actually only about 6 months old too, though I'll check it works properly still after being left standing. I will run it again tomorrow to see if the fan comes on at all with the different sensors, and otherwise fork out the dosh for some VAG ones.

 

The bitch about cooling is that every time I drain the system, it costs me money in coolant! still, it's a small price to pay, and at least the system's getting a good flushing.

 

To top it all off, I can hear a very faint rattling coming from the timing chains now, but that's another story alltogether!

[Andy T 0]

Is the water pump working ok? with the exp. cap off, can you see coolant trickling into the exp. tank from the small bore hose? the small hose can get blocked up with crap.

[Jonny_L 0]

An update. I took the car for a 30 min drive the other day, and the oil temp reached 126 degrees! The the water light came on (turned out it had an air lock :roll: ).

Airlock sorted now, and I realised the oil was only about half way on the dipstick marker (that'll be me putting 5 litres in and forgetting to buy another litre!), so I topped it up, and it appears to be running ok now.

After 15 mins, the oil was only at about 90, water nice and low too. After 30 mins, the oil temp was sitting at 116, but was showing no sign of rising further this time, though it hit 118 for a second or 2 after I gave it some welly.

 

So to me it seems to be running ok, if a little on the warm side still, though it could just be a warmer engine than my old one somehow, couldn't it? I was also wondering if maybe the auto box is causing it to run warm, since the engine's out of a manual.

So unless there's something else that should be checked out, I'm thinking i'll be ok now, and maybe stick an oil cooler on my shopping list when it starts getting warm outside. :D

 

Any thoughts?

[Andy T 0]

The autobox is watercooled isn't it? is it all plumbed in as per your original engine? Standard water-oil exchanger ok?

[Jonny_L 0]

Yep, and it's all plumbed exactly as it was. Excuse my ignorance, what's a water-oil exchanger?

 

For the record, I was told last time it was in the garage that the water gauge is out, though i'm not sure what way so I'll try and plug it in to VAG-com again to get a better idea, with a bit of luck it'll be about 7 degrees too high, which would mean it sits at 100 degrees. I can only hope :)

[Andy T 0]

It's the cooler above the oil filter, the coolant runs through it to warm the oil during the warmup period, and to cool the oil during normal running.

 

Not sure how VAG-COM checks the water temp, assume it gets a signal from the yellow temp sender, so it would show up a fault in the gauge but not a fault with the sender if you know what I mean.

[Jonny_L 0]

Ok turns out it's not fixed at all. Today it started to get really hot again, 120 degree oil, and the water temp reached 115 ish on the gauge (which is apparently inacurate anyway, as I said before). I didn't hear the fan, so i'm assuming that's still an issue. Water light came on, I pulled over to have a look.

The level was too high, so I assumed it was another air lock, let it cool for a bit and carried on.

Then the light came on again, and I have a leak from what appeared to be under the expansion tank. I'm assuming that is a thermostat issue, though I've not checked for waxy bits in the water yet. If it is, I suppose it's a question of whether it's the cause or an effect of the problem.

 

First thing i'm gonna do is take it back to the garage and have a word. This'll be the 3rd time for the same problem, so they better pull their fingers out.

 

What's worse is this time I had 2 mates in the car who are forever ripping it out of me coz I have so much trouble with VW's but stick with them regardless. I'm never gonna hear the end of it now :roll: