Technical Panda Overheating

[Torridon1]

Hi,
My 1992 Panda 999CLX has started to overheat.
Guage climbing to 3/4 (it usually stays just below midway). Fan kicks in and it keeps it from climbing higher.
When I turn the heater to fully hot, no hot air is coming out.
Is the no hot air coming out indicative of a particular problem?
The car is running smoothly otherwise (so I don't believe it is a timing/tuning issue)
Many thanks

 

[Greasytrucker]

Thermostat stuck closed perhaps?

 

[Torridon1]

Thanks. Thanks for replying. I should have mentioned that the coolant pipes at the top and bottom of the radiator gat hot, which I think shows that the thermostat is opening (?) but happy to be corrected

 

[Greasytrucker]

Depends on where the thermostat housing is?

 

[Greasytrucker]

Obviously if the pipes either side of the thermostat are getting hot then that can’t be the case. This could be ruled out by removing the thermostat and taking for a quick drive and see if the overheating stops, good thing is it only costs you a bit of coolant to try this

 

[jackwhoo]

Check heater matrix for trapped air
And general coolant leaks
Especially at heater control valve on heater matrix near bulkhead under bonnet

 

[Mike1alike]

How is the coolant level?
No hot air coming out is indicative of clogged heater matrix. Radiator could be the same, that's why overheating.
Even if radiator gets hot, that does not exclude thermostat failure. Maybe it opens, but not all the way and that matters. How old is the thermostat?

 

[Torridon1]

Apologies for the late response.
Thermostat is at least 16 years old (ie I have never replaced it)
I will drain the coolant, flush the system, replace the thermostat and refill the system according to the Haynes manual and see where that leaves me and report back

 

[puntodad19]

Yes a dicky thermostate may be your immediate problem, so check that.

Coolant colour odd would indicate corrosion blocking rad and or heater matrix, as well as water passages in the system possibly.

Summertime is the ideal opportunity to flush flush flush cooling system. Refilling with neat water ( soft variety, you ever seen a kettle using hard water, like London water ? ) and running car for some time, like a daily commute, and reflushing, repeat untill coolant comes like clear water....then after last final flush and refill to confirm no system leaks, refill with corrosion inhibitor/anti freeze.

After a run, stop engine and feel rad core for cold areas, meaning a possible blockage in that area. Be carefull about that fan suddenly starting up.

I expect flush water to be like thick strong tea initially.

How is expansion tank, very brown stained inside ?

Direct all water away from electronics/starter motor/alternator etc..all water !

Nice warm weather at the moment so enjoy

As a matter of interest, when was cam belt and water pump changed. Water pump impellors can wear/corrode....

Basics first, thermostate and a really good flush....

 

[Torridon1]

OK - I drained the old coolant, which was discoloured and had sediment etc and then I flushed it through with a hose. I replaced the thermostat and then refilled until the new coolant came out of the radiator and heater pipe bleed plugs. I ran the engine, bottom and top pipes got hot, one after the other (the thermostat seemed to take a while to open) until the fan kicked in and allowed the engine to cool before topping up. But when I returned to top up, the reservoir was still as full as when I started.
It seemed like there is no coolant circulating which suggests the pump was at fault, although it is definitely turning with the cambelt at the correct tension.
Left it overnight and I had to use the car for a quick run this morning and checked the coolant level and it dropped below minimum so topped it up to just above minimum and ran fine and at normal temp for the 25 minutes I was out.
I feel my car is messing with my head