Hi all, please stick with this story as the problem has been ongoing for so long it may turn into an essay.
First of all I am talking about a 1996 Audi A6 Avant with a 2.6 V6 (so many 6's).
This one;
new audi 001 by route9autos.co.uk, on Flickr
A few months ago I replaced the coolant tank as the overflow pipe connection had split and I was slowly loosing coolant, while warm it was evaporating through the split.
I dropped the coolant from the radiator, replaced the tank and re-filled.
All was well but about a month later I was driving at night and while stuck in traffic I noticed that my voltage would drop, dimming the lights for a moment then it would pick up almost straight away.
When I parked up and checked under the bonnet the fans were coming on for a quick burst, about 4 seconds and this was tying into the voltage drop. I seem to remember the fans would run all the time but at a slower speed than they were running now.
A few days later the car boiled over as the fans were still only coming on in short bursts (only when the air con was switched on) but the temp guage did not cimb above 90 degrees.
I changed the fan switch, no change so I rigged a toggle switch temporarily to switch the fans on manually when needed and this was working to keep the engine cool but I forgot to switch them on the other day and again the car boiled over.
What I noticed when under the bonnet was the top water hose was too hot to touch but the hose from the water pump to the bottom of the rad was no where near as hot and the fan switch was still almost cool.
Does anybody have any idea where to look for the fault? I have been through the relays and they all seem to work.
Coud the thermostat be faulty? Would this cause the electric fans to come on full pelt causing a voltage drop?
Thank you very much for any help you can give me as its the only thing (appart from a dodgy exhaust clamp) spoiling a nice car.
Cheers,
Dave.
First of all I am talking about a 1996 Audi A6 Avant with a 2.6 V6 (so many 6's).
This one;
new audi 001 by route9autos.co.uk, on Flickr
A few months ago I replaced the coolant tank as the overflow pipe connection had split and I was slowly loosing coolant, while warm it was evaporating through the split.
I dropped the coolant from the radiator, replaced the tank and re-filled.
All was well but about a month later I was driving at night and while stuck in traffic I noticed that my voltage would drop, dimming the lights for a moment then it would pick up almost straight away.
When I parked up and checked under the bonnet the fans were coming on for a quick burst, about 4 seconds and this was tying into the voltage drop. I seem to remember the fans would run all the time but at a slower speed than they were running now.
A few days later the car boiled over as the fans were still only coming on in short bursts (only when the air con was switched on) but the temp guage did not cimb above 90 degrees.
I changed the fan switch, no change so I rigged a toggle switch temporarily to switch the fans on manually when needed and this was working to keep the engine cool but I forgot to switch them on the other day and again the car boiled over.
What I noticed when under the bonnet was the top water hose was too hot to touch but the hose from the water pump to the bottom of the rad was no where near as hot and the fan switch was still almost cool.
Does anybody have any idea where to look for the fault? I have been through the relays and they all seem to work.
Coud the thermostat be faulty? Would this cause the electric fans to come on full pelt causing a voltage drop?
Thank you very much for any help you can give me as its the only thing (appart from a dodgy exhaust clamp) spoiling a nice car.
Cheers,
Dave.
