Car Heating up

abakan

Hi,

I just noticed that the tempetature gauge in the car was well over half way when coming into work.

It was a half hour drive in dublin, stuck in traffic going into the center. Also i noticed that there was no heat coming out of the fan.

what do you think would be the main reason for this?? as I think ill get it fixed but if its a big problem I might look to sell it - the car is a 98 Megane

any thoughts appreciated

BrianD3

Well I would be worried that there was no heat from the heater. Was it on full blast? Has the heater worked fine up until today?

A cold heater and a high temp gauge could indicate little or no coolant in the engine. So first thing to do is check the coolant level in the expansion tank.

abakan

yes it was working fine up until today - had it on full but still cool air coming from it.
I had the car serviced there 3months ago so i presume they put coolant in the tank

ill have to check that later on

colm_mcm

Make the following observations while the vehicle is not hot or running.

These steps combined should take a few minutes,

Is the Coolant full?
Is the Coolant mixture OK? Hydrometer reading ok, color ok, no oil in coolant?
Radiator cap OK (no cracks and swelling)
Radiator has clean air flow path? Bugs? Leaves?
Radiator dented or otherwise obviously damaged?
Hoses OK? Feel them.
Coolant in oil? Yellow gunk on oil filler cap?
Water pump turns easily? Without excessive shaft play? Any signs of leakage?
Fan Belts OK, with reasonable tension?

Now some observations with the engine running:
Fan runs when hot?
Heater work? Heater hoses hot?
Radiator flow? View flow after draining a few inches of coolant. More rigorous tests require removal of the radiator.
Bubbles? Look for bubbles or foam in the coolant in the radiator. If so, there might be a head gasket problem. The block tester or smog sniffer will tell.
Steam from exhaust? If so, suspect head gasket problem.

lomb

thermostat stuck, thermostat gate valve i think problem, should be cheap to fix

abakan

thanks for that colm ill can check them later - i hope its just coolant.

I think its just because the car was in slow trafic - when driving up yesterday, it was grand presume because the car was sitting at 100kph most of the way

I dont think the thermostat is stuck because it was moving from the bottom to about 3/4 mark

BrianD3

I'd say its most likely that the coolant level is down for some reason. You might have a leak from the water pump, rad etc. Also if your Megane is a 1.4 petrol it will have a metal coolant pipe near the exhaust manifold, these pipes are notorious for rusting through and leaking.

I doubt that its the thermostat as if you had a stuck closed or sluggish to open thermostat you would have a roasting hot heater.

maidhc

abakan wrote:

thanks for that colm ill can check them later - i hope its just coolant.

Lack of coolant is a symptom, not a disease.

Exact same thing happened me before, and it turned out the water pump was leaking. It is normally one of the easier problems to diagnose!

Our man in Havana

Probably the coolant level. Might also be that the fan is not coming on when the engine reaches a certain temp?

Henry Ford III

I agree with what Colm said above but, it could also be an air lock in the heater rad.