Cooling System....problem ?

[grantw]

Got a strange one that at present doesn't present me any problems but invite any relevant input. The heater on my wife's
PH.1 Clio 1.2 RN wasn't too good when we bought it several months ago, anyway back-flushed and all was good.....for a while,
until it again isn't too warm. The curious thing is though, for one I've never heard the fan running (as the temp.has never reached that point) and tested it just to make sure (it was OK!), and, secondly the pressure in the expansion tank is never high and the cap can be released after running without the usual output of steam/ water. Noticed a small hissing today from the cap which looks like the weak point...but, my point is- is this a problem ? If the engine's staying cool enough (even at idle) and coolant level shows no significant loss....?

 

[benji&eka]

probably a faulty thermostat, stuck open so the engine never really gets up to temperature

 

[grantw]

Forgot to mention that-the thermometer was renewed when I had the initial heater problem.

 

[grantw]

Oh..and the engine temp. reaches half-way point within a few miles of setting off-so can't see a problem there ! Strange...

 

[benji&eka]

Forgot to mention that-the thermometer was renewed when I had the initial heater problem.

i take it you mean thermostat, its still worth taking it out and checking its closed when its cold. also did the system get bled properly, do the top & bottom pipes on the rad get nice & hot. also do the pipes into and out of the heater matrix get hot?

 

[grantw]

Sorry, yes the thermostat. All pipes get hot, albeit maybe not as hot as they should be.

 

[benji&eka]

i'm sticking with a faulty thermostat or a blockage/airlock in the system. you could try taking out the heater matrix and seeing if its blocked or damaged

 

[grantw]

Ok Thanks for the advice