aby getting hot

[peter]

i own an aby avant temperature is fine when underway but gets up too 100c before fan cuts in,excess temp seems to reduce boost/timing above 3500 rpm untill engine returns to 90c.no warning alert comes on but idle temp reaches 109c if left to its own devices.fan does do after run cycle,rad switch(3 pin) and thermostat have been replaced.please help!

[s2avant95M]

i own an aby avant temperature is fine when underway but gets up too 100c before fan cuts in,excess temp seems to reduce boost/timing above 3500 rpm untill engine returns to 90c.no warning alert comes on but idle temp reaches 109c if left to its own devices.fan does do after run cycle,rad switch(3 pin) and thermostat have been replaced.please help!

what about the coolant? has it been replaced recently? im no expert, but im sure somebody more knowledgeable than me will come up with more suggestions..

[dan_b]

Airlock in rad? Leaking rad(s)? Wrong type of coolant? Something blocking the airflow to the rads?
Who replaced the thermostat, was it the right type?

[s2driveruk]

hmmm, does the fan kick in at all to control the temperature? mine cycles on and off just about 90 degs running for about 15-20 secs at low/med speed.

Sounds like possibly the wrong rad switch has been fitted as yours kicks in at different temps to mine, i think it should start the fan at 87(?) degrees.

David

[Pete_RS2]

Mine is the same. I think it's the mid-speed/'High Speed 1' which isn't working. 'Low Speed' fan works for a/c & after-run and 'High Speed 2' works at ~102 degC. Nothing in between.

I've changed the rad fan switch and swapped the 3 fan relays around in the fusebox which didn't move the problem. Next thing to try is the 3 terminal fan resistor pack located behind the bumper.

I think the thermostat also needs changing as the temp gauge sits at 3 marks below 90 degC with the colder ambient temps we're getting now.

[Martynf]

who changed your rad switch!!! the stat isn't going to make any differece to the needle (from experience!) I'm on teeh 3rd stat thinking that the 1st was a new part 'failure' as the needle sits 3 clicks under since i chamnged it. Guess what teh 2nd stat did too?? and guess what teh 3rd one does as well? cannot be stat, more likely gauge lying! cause, sender, voltage reg or gauge.... cannot be bothered...

[Martynf]

and how come you haven't fixed speed 2 yet???

Peter (who started the thread) your problem is probably exactly the same as Peters above, the rad fan speed 'resistor' fitted to the inner wing, it's probably just burnt out the speed 2 windings as its the most used speed overall and speed 3 goes direct to fan, no resistance. Also to be checked is teh 2nd speed relay in teh fuse box under the bonnet. Luckily there are two relays exactly the same, so you can swap them about to test speed 2.

If the relay swap doesn't cure, then you need a speed resistor part number 447 959 493B @ £73.33+vat from us, £105.15+vat from the dealers.

Before you commit to htis part, check the relay and also check the condition of the wiring going to this speed resistor, if the siring to the terminal pins is really badly corroded, then the fix could just be a file and some WD40!!

HTH
Martyn

[Pete_RS2]

OK it was Martyn that changed my rad switch.

A technicality Martyn

[Martynf]

he he he he....... hoiw much coolant was lost???huh, huh???

[Pete_RS2]

he he he he....... hoiw much coolant was lost???huh, huh???

Yes my apprentice did a pretty good job there. I didn't even have to top up the coolant.

and how come you haven't fixed speed 2 yet???

No time Martyn. What with the lack of daylight now. Fortunately it hasn't been an issue with the lower ambient temps.

[audiman]

back to the original poster. IS the car ok whilst driving?? or does it still sit high?

[peter]

aby getting hot

and how come you haven't fixed speed 2 yet???

Peter (who started the thread) your problem is probably exactly the same as Peters above, the rad fan speed 'resistor' fitted to the inner wing, it's probably just burnt out the speed 2 windings as its the most used speed overall and speed 3 goes direct to fan, no resistance. Also to be checked is teh 2nd speed relay in teh fuse box under the bonnet. Luckily there are two relays exactly the same, so you can swap them about to test speed 2.

If the relay swap doesn't cure, then you need a speed resistor part number 447 959 493B @ £73.33+vat from us, £105.15+vat from the dealers.

Before you commit to htis part, check the relay and also check the condition of the wiring going to this speed resistor, if the siring to the terminal pins is really badly corroded, then the fix could just be a file and some WD40!!

HTH
Martyn

many thanks to you all,i think youve hit the nail on the head,the fan only runs at full speed,i will check out relay/resistor for damage and let you know,i think thermostat was suspect anyway as i was getting huge variation in temp when driving,get a steady 85c with new stat (genuine part).thanks again peter.

[Pete_RS2]

Well my fan still doesn't come on until ~100 degC. The rad switch & the speed resistor pack have now been changed on mine so I think they can be ruled out together with the relays as we swapped those around too. Is there anything else it could be ? I don't think the gauge is lying because as soon as you switch off after reaching this temp the after-run speed is activated.

[Pete_RS2]

Anybody know if there is anything else which could affect the fan operation ? What about the MFTS in the water rail ? I need to get to the bottom of this before the summer sets in otherwise I'll end up cooking the head gasket.

[porkkis]

Actually what is the problem? The fan should not come in before 100C. At around 105 the fast speed kicks in. Can't the fan control the heating or what's the problem?