Overheating

[ccconn]

Ok had this for a while and fed up trying so thought I would ask the collective brains

My 1.8 (was VVC now DVA solid cams etc) likes for the past three years to run its fan almost all the time once warmed up

I have replaced

1) Hoses to silicone

2) Fan switch twice

3) Radiator for a Racetech heavy duty one

 

The system has been bled and the gauge only shows 80 pretty much all the time once warm

Its not connected to the EMU either

 

Any ideas would be great - One thought was maybe the water pump is playing up but I thought that would have shown on the gauge?

 

Chris

 

[Eugene]

Sounds like the fan switch is falty in some way - what temp is it set to?

 

I had a similar problem with my Zetec with the fan switch set next to the thermostat.

I relocated it to the rad and it works fine now as the rad temp is always lower than the thermostat.

 

Small Boy - with Loud Toy!

Co-founder of the BOG Club

See Eugene here

and see what I do here

 

[BYKer Will]

radtec has the fan switch on the inlet side (if you fit it correctly) at the top whereas the caterham rad has it on the cooler outlet side.

 

The caterham fan switch is set to allow for this and therfore if you change to radtec and keep the original fan switch my guess is the fan switch is seeing hotter temps than before and is therefore switched on all the time.

 

Solution is to change the fan switch. I am looking for an 88 82 which exist but I cannot find one anywhere.

 

W

[CageyH]

Are you sure it is ov erheating?

Run the engine with the bonnet off,and check all the hoses warm up. You may have a failing thermostat.

 

Only dead fish go with the flow....!

[tweeky]

have you tried expansion bottle cap ?

 

Tweeky

 

to infirmity.................... and beyond

[elie boone]

BYKer Will, cbsonline.co.uk has a 88-79 thermostat switch M22x1.5

[oilyhands]

Why not use the ECU to switch the fan? You just need a relay and one trigger wire to the ECU (pin 6). The ECUs idea of the engine temp can then be used..

 

Oily

[ccconn]

If i remember rightly the ECU switches negative does it not?

 

c

[bobt]

Yes, it is switched earth. If you are going to make this mod, and you have a big red starter button fitted can I make a suggestion. I find that when restarting a hot engine with the fan running, the starter can labour. ECUs (well emerald at least) don't give you the option to gate this fan trigger with engine RPM. You could then set it to only trigger when RPM is also greater than 500rpm. To get round this, the big red starter button has another set of contacts on it which are 'Normally Closed'. Run the fan Relay ground lead through these contacts first before going back to the ECU. This way, should the fan be on during a hot start the relay is cut under cranking :-) No more groany restarts in petrol stations after you've had to queue.

 

Rob