Radiator

And I was pissed off when my gauges all stopped working

I am not now, from what I am gathering they don't give any accurate info anyway

Oil pressure .....yes; it hasn't seized yet
Temp ....No steam ....I guess all is ok ....monitored through the rear view mirror


si21 ......Yet

Shoe String Racing

My money is on the good old thermostat!

I had similar issues for absolutely ages and went through various (and expensive) options trying to figure it out, some more puzzling than others. (I'm sure Clee et al might remember my custom chicken temp probe avec cork)

Long and the short of it was that I pulled what had been a new thermostat out and dropped it in a saucepan of water. Sure enough it opened, and at the right temp, but it wouldn't open fully. Clearly it was a duffer from day one. With the new new thermostat in the pan alongside it the difference was obvious.

If you think about it the pipes (and therefore water flow) in an Alpine is a long distance. It's no surprise that with a partially opening thermostat it will allow 100+ at the engine whilst the rad is still reading 90. It just takes too long for the water to circulate.

Get a new thermostat if in any doubt as it's the cheapest fix you can make.

Also rev the engine just a fraction whilst in neutral. If you see the gauge rise it's almost certainly flow related so again thermostat or the option of a blocked rad!!!

Also rev the engine just a fraction whilst in neutral. If you see the gauge rise it's almost certainly flow related so again thermostat or the option of a blocked rad!!!

More likely the gauge rise when you raise the revs is caused by the alternator rising the voltage a little, as the temp gauge like most other gauges in cars is just sender unit controlled voltmeter.

Possibly, but for the fact that it didn't do it one the thermostat was replaced!

It's simply restricting the flow - that water should be pumped out and replaced with cooler water and if it can't get past it's just going to raise the temp.

Disconnected the flying lead from rad temp switch and couldn't get a reading on the multimeter. Hence looks like it's gone open circuit, which I guess will not allow the fan to come on.

Pretty sure the replacement is a 77 00 777 684, Intermotor p.n. 50112.
However, there is a 77 00 777 683, Intermotor p.n. 50113. But I think this is for a D503 (GTA with a Cat ???)

Around £30 from Motor factors or £20 from Ebay.

Disconnected the flying lead from rad temp switch and couldn't get a reading on the multimeter. Hence looks like it's gone open circuit,

Paul, just for clarifacation, I take it you put the meter across the switch when the temp of the coolant was well above the 90` reading on the gauge.

50112

2 wire with flying lead

http://www.buypartsby.co.uk/temprature- ... eng=2.5000

D502 is a Le Mans/GTA with Cat
D503 is A610......

Lee

I'm sure the one I got from Simon Auto was only around €15.
Agree with Jon C on this one - the sensor will be open circuit when the radiator is cold, only closed circuit at/above 90 degrees.

When I had trouble with the fan, turned out the fuse for the fan had blown (worth checking) because the fan motor had seized and then burned out. Of course, the fuse was the last think I checked, not the first...

Ooops, I mean John C. Sorry John.

Don't seem to be able to edit my post - probably need 'member' status.
Believe it or, I've paid my membership now!

I short circuit the fan and it kick in fine.
As the only thing that drives the fan is the temp sensor, then it must be this that is not working correctly.
I'll replace said switch and see if that helps.
I've checked for air locks already.

What a difference a new temp sensor makes !
It now turns the rad on just over 90 and stays on till it goes back to 90 - not like the previous switch which would make the rad fan stay on for 5 secs, then turn off for a while and then back on for 5 secs etc etc..

Turned out the temperature sender at the themostat was dicky too.
The gauge was showing 120 degress when it clear;y wasnt!

Fitted new one (after finding details on a previous thread) at it's operating correctly now.

Many thanks to Turbodog for his advice..

Paul