NelsonUK

I appear to have a problem with my car MY93WRX which is worrying me.

Basically what seems to happen is leave the car to idle and or drive the car around town and it seems to be fine. Take it for a couple of miles spirited driving and again everything is o.k. However drive the car 10 miles on the motorway at a constant 85-90mph and pull off in a service station and as soon as the car comes to a halt on comes the rad fan. Literally the fan comes on as soon as the revs drop to 800rpm. If you blip the pedal then the fan stops. I can hear the switch behind the dash clicking on and off as and when the fan kicks in. The worrying problem is that tonight I have driven 20 miles on the motorway at speed of approx 90mph - pulled off and then driven into town (a couple of miles) and as soon as I pull up outside the house click on comes the rad fan. I waited for a minute or so and the fan eventually stopped. When I then felt the coolant tank - red hot - then felt top rad hose - again red hot - felt pipe along the top of the rad and the bottom rad hose and they are both cold??? Now the temperature gauge doesnt move (but I understand that these aren't that accurate anyway). Not many months ago I changed the coolant temp to ECU sensor, flushed and replaced coolant and have changed the thermostat. However the problem persists ?? I am getting a tad worried now cos my intial thought is head gasket (although I must admit no mayo in the oil and water level aint dropping) or is there a temperature sender on this car somewhere that might be faulty ?? Any help would be greatly appreciated cos I am on the verge of trading the scoob in for something more reliable

rayman_2

probably the coolant temperature sender. Got a prob on mine at the moment, soon as i start the scooby the fans kick in and it idles irractically.

Brought a sensor from gramham goode 35+vat, going to fit it this weekend. Do you get a check engine light ?

s-man

Howdy

My 95 Uk Turbo does EXACTLY what you describe...to the letter! If I drive on b roads etc then fan never kicks in but steady motorway even at 65-70 mph for 5-10mins and the fan always kicks in as soon as I stop. I get the same clicking when I blip the throttle and to be honest I had kinda accepted it as a quirk and often just use the fan time as a sort of enforced turbo
cool down phase but Ive never been totally comfortabe with the reasons why it might be happening.

I've had a replacement coolant sensor on mine after I first got it looked into (a year ago now) but it still does it. I get no CELs and no other weird effects - although you finding cool hoses on the bottom of your rad makes me want to go and check because that sounds like an airlock or something.

My car has been into a specialist for 2 services as well as various other major jobs and they've never solved it & say not to worry but it still bugs me as well. If you find out anything I'd appreciate it if you shared the info - cheers

Steve

NelsonUK

many thanks for the replies.

Rayman - I did the coolant temp sensor - bought it from graham goode and replaced it a couple of months ago (still have the scars to prove it). Would be interested to know how you get on with the job as I found it a real b1tch to do.

S-Man - phew nice to know I'm not the only one with this problem - whether thats a good thing or not remains to be seen. The thing is I have replaced the temp sensor in the engine however I seem to remember a previous post mention a temp sender unit in behind the dash. Now this would explain why I can hear the clicking behind the dash. My worry is that if the temperature sender is giving the car the wrong readings then it may be running too hot etc. Like I say I know its not the coolant sensor and or the thermostat cos I have changed these. Could be an air leak I guess - I will try undoing the tap at the bottom of the rad and run the ar up to temperature and see if that makes any difference. Just to add insult to injury having collected the car from the garage yesterday they had the car running for approx 45 mins - to check some gasket seals were o.k. When I collected the car in the evening the car was still warm - drove the same stretch of motorway and guess what - pulled off and no rad fan......talk about weird...??? I will keep perservering with this and would appreciate anybodys elses comments.

cheers

s-man

Nelson - I know...I saw your post and thought phew but then i thought 'hmm' again after reading. I'm just not sure all is as it should be and I hate not having 100% confidence in the car.

I'd be keen to hear how you get on regarding the other sensor - I have always thought my car ran a bit hot since i got it. I've never had it quantified or anything but ever since I got it I've noticed the odd whiff of hot oil and/or other fluids that sometimes seems to appear after a good burn.

If you can find out anymore about that 2nd sensor I'd be grateful if you would share - ta!

Jolly Green Monster

iTrader: (4)

I was reading yuou explaination thinking that you are describing what it is suppose to do..

then the cold bottom and hot top of rad..

Firstly double check you have enough water in the system..

It sound as if it is not circulating properly.. I'd replace the themostat... and check for leaks / blockages..

I'll check the diff between top and bottom of rad on mine when I get the chance and report back as mine doesn't do this.

JGM

NelsonUK

Cheers Jolly - please let me know how you get on. As I have previousy mentioned I have replaced the thermostat not that long ago so I am hoping its not that cos it was a b1tch of a job

It could be an air lock problem - I have read previous posts that talk about the tap at the bottom of the rad to release unwanted pressure - maybe this is worth trying.

NelsonUK

Hmmm - have drive the car this morning - about 20 miles - a roads mainly - altho I did get her upto about 70ish. However I really treated the car gently. Got home and felt the top rad pipe - very hot - bottom rad hose - warm... so it would appear to me that the thermostat is opening and the car is getting up to temperature ?? I cant help but think there may be a sensor or something that is giving false readings or something ??

Can anyone please tell me whethe there is another temerature sender apart from the coolant sensor ?? Any advice would be greatly appreciated.

Oh yea btw last night I did actually pop the collant cap off and ran the car for a little while whilst pressing the pipe to see if there was any air locked in the system. This may have made a difference I'm not sure - I'll keep you posted.

Tone Loc

iTrader: (1)

The way the fans work is exactly as i would expect, driving at constant motorway speeds there is a big build up of heat in the engine.

Couple of questions.... do you have a decat downpipe? If so have you put the heatshield back over the turbo? This will stop a lot of heat soak going on under the bonnet.

Also the radiator not getting hot... what have you got the heater on. If the heater is on hot then the radiator won't get that hot. Basically because the heater matrix is doing alot of the heat transfer that the radiator will normally do. I expect that due to the cold weather you would have the heater quite hot. Check by idling the car with from cold with the heater on as hot as possible.... it will take for ever for the radiator to get hot.... only the top hose and a little of the raditor will get hot. Flick the heater on to cold and the radiator will heat up in seconds.

Let me know how you get on,

Tony.

rayman_2

Hi Nelson just fitted the coolant sensor. Runs okay no check engine light and fans are now behaving.

What i did notice was you do need to make sure the coolant is filled up properly. I ran the engine a couple of times and filled it up from the expansion tank. after that the fans came on when the correct temperature was reached.

the sensor was easy to take off as long as you take the induction off completly, use a 19 spanner. putting the sensor back on was a bast**d, the sensor fell down into the bottom of engine bay near the power steering rack it took me an hour to locate it back. put some tissue down near the plug to stop it falling. Once its on takes 5 mins to tighten and put the plug back on. fill coolant via the tank. Squeeze the top coolant hose when pouring the coolant this helps it get around the block and rad.

hth