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(1995 to 1999) 1.25i Zetec - Overheating - nlr1966
Hi, I'm a real no-hoper with cars, so any help greatly appreciated:

My Fiesta has been overheating when driven further than 4 or 5 miles. The radiator stays cold even when the car is overheating. Also, the heater does not get really hot, just warm, even on full heat setting. The hoses to/from the expansion tank seem to be getting hot (although I don't know which is which!).

I've been told by the RAC that it is the water pump, although I've also been told it could be the thermostat. Bearing in mind what I have said, which is more likely?

Thanks in advance for any help.

Edited by Webmaster on 12/12/2007 at 01:43

Overheating - Andrew Scott
In my opinion almost certainly the thermostat.

I am surprised however the RAC mechanic (These guys are skilled) think it is more likely to be the Water Pump, presumably no loss of coolant and the pump is being driven.

Andrew

Edited by Dynamic Dave on 11/12/2007 at 21:07

Overheating - jc2
If the thermostat failed shut,the heater would be hot-if it failed open ,the radiator would be hot.Does sound like pump.
Overheating - L'escargot
Airlock?
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L\'escargot.
Overheating - RichardW
"Airlock?"

Airlocks don't happen spontaneously in cooling systems, it's an urban myth as far as I'm concerned - you've either got to have had work done, or lost some fluid first and the refilled it to trap some air (unless it's been stood a long time, and corrosion gases have accumulated at a high point - unlikely though).

Providing that it's got water in it, then it does sound like the pump is shot.

--
RichardW

Is it illogical? It must be Citroen....
Overheating - jc2
Airlocks are unlikely on Fords built after 1985;they have systems designed to get the air into the header tank;most Ford header tanks have at least three connections to the engine and hoses.
Overheating - Screwloose
Is this a Zetec-S 1.6? What year?

Edited by Screwloose on 11/12/2007 at 10:51

Overheating - DP
You say the heater doesn't get hot, but does the heater control have any bearing on the engine temperature? Turn the heater temperature control to its hottest setting and see if it improves the situation, then report back.

I cannot begin to explain the grief I had with an overheating Fiesta this time last year, or the amount of time and money I spent (pointlessly) replacing most of the cooling system when a design fault in the heater control valve was effectively shutting down the cooling system whenever the heater was turned off.

Cheers
DP
--
04 Grand Scenic 1.9 dCi Dynamique
00 Mondeo 1.8TD LX

Edited by DP on 11/12/2007 at 11:50

Overheating - Screwloose
DP

Hence my question about the engine.....
Overheating - nlr1966
Wow, there's a lot of knowledge on here! The car is a 1.25i Zetec.

Regarding this comment: "You say the heater doesn't get hot, but does the heater control have any bearing on the engine temperature? Turn the heater temperature control to its hottest setting and see if it improves the situation, then report back." - At first, the overheating was reduced when I turned the heater to it's hottest, but now the effectiveness of this has lessened and also the air blown into the car seems to be cooler than previously. Thanks in advance agin for any help.
Overheating - Rattle
A long shot but I have been told that on the zetec the heater control valve can cause it to overheat if that is faulty. This ONLY what I have been told and cannot say how accoruate it is.

Edit sorry DP has already mentioned that possibility :). It DOES only effect the Zetecs though.

Edited by Rattle on 12/12/2007 at 22:43

Overheating - DP
I can confirm it definitely happens.

I replaced water pump, radiator, heater matrix (leaking anyway) and thermostat (twice) in a futile attempt to stop the car overheating. Got a pattern heater valve from Ebay as a last resort before pxing the car (it got to the stage we just didn't want the car any more), stuck it on, and the problem went away instantly. Then I noticed in the service history that the valve had been changed by a Ford dealer 2 months before the previous owners sold the car on to us. I would bet a year's salary the car started overheating as soon as this valve was fitted. Even months later when we were trying to sort it, Ford dealers were pleading total ignorance, and Ford UK were denying all knowledge of the problem I suspect the previous owners lost patience and sold the car on which is what we were about to do.

I test drove the car in -2°C and snow, so the heater was on full. In this state, the car was fine. In fairness, once this was fixed, the car was a cracker and never gave another day's trouble.

I am doing this from memory, but the affected valves are genuine Ford items with part numbers beginning 98. Part numbers beginning 96 are not affected, and my understanding is that new parts from Ford with the 98 part number are OK. Mine came off Ebay anyway and only cost twenty quid.

Cheers
DP
--
04 Grand Scenic 1.9 dCi Dynamique
00 Mondeo 1.8TD LX

Edited by DP on 13/12/2007 at 09:58

Overheating - gm3suz

My Ford Fiesta 199 1.25 engine has had a heating problem for about 2 years, the heater blows hot air, even at the cold setting. I have replaced the heater control valve 3 times, first two times with an e-bay one and 3rd time with one from a local parts supplier. Each time the car would run for anything from a week to a month with no heater problem but of late I am almost being cooked because the air conditioning does not work either, it has a leak that will cost a fortune to fix. In desperation I got a circuit board from a car breakers yard and fitted that and it made no difference. Someone suggested that if the thermostat failed in the closed position, the heater would stay on, I have bought a new thermostat but it's going to be a pig to replace it. Can anyone give me a clue as to what the problem could be ?