Technical heater issues when cold

[london panda man]

hi

ive got a 2007 panda 1.2 dynamic, its been running perfect since ive had it. but the last few years in the winter it takes much longer for the engine to get up to temperature than it does in warmer times of the year. This is understandable due to the weather. But if I put the heater on then the engine temp starts to go down.

If i wait about 30mins or so before putting on the heater its fine.

It never overheats or anything so i'm not overly worried.

Is this a serious issue or just one of those things?

cheers.

 

[Matt100HP]

I'm not sure, but it could be a faulty thermostat. They're not expensive to replace, so unless anyone has a better idea it could be worth a shot.

 

[daveofkent]

I think it might be one of those things, has anyone tried blocking off part of the rad with card for the colder months?

 

[Sweetsixteen]

Poss lazy stat?

I run all year round with my grill totally blanked off on all my vehicles. One is a towing workhorse.
They like the quicker warmup.

We used to import cars into Malta (from the UK), where summer temps are often above 40degs. Every car had grille blanked, and never overheated. They often ended up in Tunisia, where it's even hotter.

Cars are built for extreme conditions, and virtually all UK cars are grossly over cooled.
Someone's bound to shoot me down with a different viewpoint - but so far it has been a win/win situation with no downside.

 

[A3jeroen]

Thermostat not closing completely. Best giveaway is normal temp at the trafficlight and going down a little bit when you pick up a little sped. I think nowadays thermostats are designed to fail in the open position opposed to the 70's when they would always fail in the closed position causing overheating.
With a working thermostat there would be no need to cover up the radiator. Termostat simply wouldn't allow fluid to go through the rad.

gr J

 

[Sweetsixteen]

With a working thermostat there would be no need to cover up the radiator. Termostat simply wouldn't allow fluid to go through the rad.grJ

Obviously, in view of what I've just said, I would disagree with that.

When your car is battling freezing sleet in sub-zero weather, fuel is simply being wasted trying to keep the engine at optimum operating temperature. Give the motor a sporting chance - meet the cooling system halfway!

 

[Most Easterly Pandas]

Obviously, in view of what I've just said, I would disagree with that.

When your car is battling freezing sleet in sub-zero weather, fuel is simply being wasted trying to keep the engine at optimum operating temperature. Give the motor a sporting chance - meet the cooling system halfway!

And what happens when something goes tits up with the cooling system and you've restricted all that air flow

It may seem to cause you no issues, but I can see it potentially causing issues in the summer months on a car which perhaps isn't properly maintained etc.

OP, like others have said, sound like you just need a replacement thermostat. Always get a genuine one form a main dealer, as there are too many cheap nasty dodgy ones out there on the market. Should be about £25-30 for a replacement OEM thermostat with gasket from a dealer. About 30 min to fit

 

[A3jeroen]

Obviously, in view of what I've just said, I would disagree with that.

When your car is battling freezing sleet in sub-zero weather, fuel is simply being wasted trying to keep the engine at optimum operating temperature. Give the motor a sporting chance - meet the cooling system halfway!

Obviously you don't understand how the coolingsystem works. Below operating temperature the thermostat should be completely closed. Not allowing any fluid circulation to the radiator.
The only thing extracting heat then is the heater.

gr J

 

[london panda man]

Excellent, sounds an easy fix. Thanks for the quick replies.

 

[Matt100HP]

Excellent, sounds an easy fix. Thanks for the quick replies.

It is an easy fix, it should make winter driving much more pleasant .

 

[Sweetsixteen]

Obviously you don't understand how the coolingsystem works.



gr J

I wouldn't go as far as to say that, but I'm no rocket scientist, so it's just as well that heating and cooling basics are very simple.

In the case of a car engine, its heat requirements for optimum efficiency are fairly specific, but it's heat output and heat loss are variable, governed both by its workload and it's working environment. Normally the engine will produce an excess of heat - hence the cooling system with its thermostat, which is designed to modulate it.

However, in sub-zero conditions, especially with a light workload (ie. using only a small percentage of maximum power, as when driving slowly in winter snow) the engine sometimes struggles to produce sufficient heat. This is the part that many of us forget, and that also helps explain why heaters in modern high-efficiency engines driving small, light cars take much longer to warm up.

The thermostat tries to compensate by shutting off the radiator circuit in order to keep the heat produced within the confines of the engine block, but this then leaves the radiator exposed to a large temperature drop, caused by a lack of warm water circulating through it and a continuous blast of bitterly cold air through the grille.

Even with the radiator circuit shut, under extreme conditions some frugal engines simply do not produce enough heat to reach optimum efficiency, because the heat loss is still too great - made even worse when you run your heater at max to try and keep warm!

The cooling system is just that - it is designed to cool, but it cannot produce extra heat when the engine needs it. So help the poor thing by stopping the unnecessary blast of freezing air through the grille. You'll get a warmer car and better fuel usage. Check out how the really cold countries do it if you're not convinced.