not heat from heater at low revs?

Brain

Brain

Brain

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Hmmm just noticed on the fiesta that when the car is idling not heat comes from the vents even when the temp is turned up full and the air turned up full. Thats not normal is it?
When the car is then running the heat starts coming through. So basically I think at low revs there is no heat but when driving along it works normally?

What could cause this?
 
yes - topped it up just the other day. Althoug tbh i dont know the last time it was topped up...
 
Brain said:
Hmmm just noticed on the fiesta that when the car is idling not heat comes from the vents even when the temp is turned up full and the air turned up full. Thats not normal is it?
When the car is then running the heat starts coming through. So basically I think at low revs there is no heat but when driving along it works normally?

What could cause this?
Click to expand...

This from a cold start, cause it takes time for the heat from the engine to heat up the water in the heater matrix.
 
not from a cold start - i noticed it when i was sitting in traffic - turned on the heater and no heat until i started driving. That lead me to beleive that it could be linked to the revs.
 
Brain said:
Can you explaint what an "airlock" is in this case?
Click to expand...

If the expansion tank runs empty and you fill it back up to fast, air gets trapped in the system.

It's probably sitting in the heater matrix (heater inside car) when the revs are low, and when you rev the engine, the air gets pushed around the engine.

Have a look in the engine for a little bolt connected to one of the coolant pipes. It'll normally be at the highest point of the cooling system and just before the rubber pipe connects from the engine to the radiator.

You'll have to unscrew this and rev the engine a bit to push the air through until you get a stream of coolant showing that there is no air in the system.
 
worth a try i think, thanks :)
The coolant expansion tank wasnt empty when I topped it up - but i suppose its possible its happened with the previous owner.
 
Ive taken it in to get looked at and the mechanic is very confused with my car. He says that the egine is running cold and that there must be a problem with the water circulation. He has checked out the water pump and radiator and pipes and also bleeded the system to make sure there is no air.
I think thats about what he said - not sure what he means by 'running cold'?

He thinks I shouldnt be driving it! Buti think he is saying that becasue he doesnt know the cause of the problem...
 
Ive taken it in to get looked at and turns out that the head gaskets need replaced! :( He said gave me a price of around £500-600. Doesnt that seem a bit steep?

He said that he would replace the head gasket[s?] and would also like to 'skim' the surfaces if they needed doing.
 
So the fans are on but blowing cold air when idiling or the fans are not on at all?

I would take your car for a 2nd and maybe a 3rd opinion before shelling out that sort of money, is your coolant always going down? Like rapdily every week or fortnight or so?
 
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