Overheating - fan stops when ignition off

[mannik]

Car seems to overheat as soon as I stop the car.
With the ignition on and car idling the fan comes on and stays on when the engine is warm. As soon as the engine is turned off, the fan stops and coolant runs from the expansion tank within a minute.
Any ideas?

[Le TVR]

Sounds like its time for a new pressure cap and bleed the airlocks from the system.

At a guess I would say: pressure cap on swirl tank and return valve in pressure cap not sealing......?

[GreenV8S]

If you fit the pressure cap on the swirl tank, you'll need a longer reach cap to seal properly. Or you could just fit it back on the header tank where it belongs.

[axe]

The fan stops on my S1 as well when I shut down the engine... That shouldn't happen, should it?
if not, then where do I look?

aXe

[Le TVR]

Cooling fan should stop when ignition is switched off.

[flinny]

Where can I get a longer pressure cap ??? I can't get my blanking cap to seal properly when fitted to the swirl pot (blows water out the top when switched off). So I have them the "other way round". I still have an overheating problem so would be happy to give this a try.

[axe]

I have a spare pressure cap (was stuck between the fan and radiator, found it when I removed the rad)
I think it is still in good shape... ask if you are interested, I'll have a look for it

aXe

[flinny]

axe said:

I have a spare pressure cap (was stuck between the fan and radiator, found it when I removed the rad)
I think it is still in good shape... ask if you are interested, I'll have a look for it

aXe

axe YHM

[kj]

I bought a FirstLine FRC69 pressure cap from Serco and that seems to do the job on my S3. It is long reach, has a top seal under the cap itself to seal off the top of the swirl pot and the poppet valve so that coolant is drawn back from the expansion tank as the engine cools. Had to clean the crud from the top of the swirl pot to get it to seal properly.

[mannik]

Where did you purchase the FirstLine FRC69 pressure cap (Serco) from?
Demon tweaks? Halfords?

[kj]

Got it from Serco, they are truck parts suppliers and I believe an offshoot from Partco.

When I got the car it was fitted with a Lockheed LRC 1003/90KPA part which had worn out. I don't think you can get them now but the man at Serco looked it up and came up with the FirstLine one as a direct equivalent. It certainly has all the same essential features except the pressure rating which I think is 13lb against 15lb for the original, seems to work fine though.

[axe]

flinny,

I got the pressure cap as I told you, however the main rubber seal is missing. I can still send it to you if you wish. Mail me your address and it will be yours.

aXe

[flinny]

axe said:

flinny,

I got the pressure cap as I told you, however the main rubber seal is missing. I can still send it to you if you wish. Mail me your address and it will be yours.

aXe

Cheers axe, YHM

[axe]

will be on its way tonight. You should get it tomorrow or the next day

aXe

[WorGC]

My pressure cap is on the plastic expansion tank and I've got a new 15lb one without the spring bit on the swirl pot. Having seen previous (lengthy and numerous) threads before, I just need to know if this is right or wrong. Without opening a can of worms....

[GreenV8S]

WorGC said:

My pressure cap is on the plastic expansion tank and I've got a new 15lb one without the spring bit on the swirl pot. Having seen previous (lengthy and numerous) threads before, I just need to know if this is right or wrong. Without opening a can of worms....

What is a 'new 15 lb one without the spring bit'? It sounds like a plain blanking cap, which is what you should have, but references to '15 lb' make me worry that it may be some form of pressure cap. If you fit a pressure cap on *both* tanks then your system will run at 30 psi and something's likely to go pop.

Edited by GreenV8S on Wednesday 12th July 17:27

[WorGC]

Well it's got 15lb on it, but there's just a thick rubber seal inside to make it watertight and no room for movement. The spring-loaded one is on the expansion tank....