Technical Overheating mk1..coilpack or more sinister?

[egon]

Hiya. Long time lurking, first time posting...

My daughter has a W plate 1.2 punto thats causing her issues, wonder if you guys n gals might be able to shed some light on....
I had a call saying that the temperature light had come on and the car was struggling to pull. Eventually i got to look at it and found HT leads 1&3 not connected to the plug caps properly. Sorted that out and test drove it and all was well.
On her way home it did it again. It only seems to do it when its hot (the car,not the weather) so i've ruled out the HG. I had a vectra that used to eat coilpacks for fun, is the punto the same? I'm wondering if the heat is killing off a coilpack and making it a two cylinder, causing it to over heat. The fan is working fine too.
Anyone got any ideas they could throw my way please?
Thanks muchly.

 

[dumbledore]

Running on two cylinder should not cause it to overheat, if anything should help with cooling as the petrol is not burned. The heat may kill the coilpack but not heard that to be a common problem. This is an italian car and they have heat and I would expect that will be a good test for Fiat to get coilpack design right.

 

[egon]

Thanks dumbledor, i've copied the bleeding process and i'll give it a go tonight. Unless the water pump has died, i cant think of anything that would have thd same syptoms.
No water in the oil, no oil or petrol in the water either!
I cant moan about it being an italian either as i have a 147 and a 159 at home!!!

 

[fingers99]

I'd start with a compression test.

 

[DaveMcT]

Overheating = not enough cooling or its blowing out the coolant (has the same effect). Compression test before doing anything else. If its been recently making gurgling noises from the heater area, you won't go far wrong saving up for a head gasket job.

 

[egon]

I'm off over to her house in a minute to have a look.boot full of tools and oil/coolant too!!
Hoping its not a head gasket. My gut feeling is the water pump failed but i'll report back with my findings.....(cue greasy iphone!!!!)

 

[egon]

Looking very much like a stuck shut thermostat. Bottom hose getting hot but nothing transferring thru the rad on the thermostat side....

 

[dumbledore]

I would still check if there is enough coolant in there. Also if low on power when hot it may be caused by low compression which indicates overheating may have done some damage to HG or head. As said compression test should be performed ASAP.

 

[egon]

Yeah, sounds like a plan. Off to ecp on the way home today to get a new one, fill it up, bleed it out and then compression test it.

 

[tinytim]

HGF most likely; not a difficult job to replace; plenty of posts on this; make sure system is bled properly afterwards; suggest get head skimmed and also replace water pump, cambelt, pulleys and thermostat while its apart; also oil will be contaminated so change this and oil filter and renew spark plugs...
W reg is a MK2 surely?

 

[MadMan0]

When the car says it's overheating how hot are the coolant pipes? and has the fan come on?

If the pipes are warm and not very hot then it could be as simple as the temp sensor throwing a fit. the sensors are cheap. Not 100% sure on the location on your car, it may be next to or on the rad.

IF the fans arn't coming on then check the fuses and conections to the fan.

Also, as mentioned above, check the coolant level, if it's all good then a compression check will rule out the Head gasket

Failing that, the thermostat could be passed it's usefulness and may need to be replaced. About £5 each with new gasket. (gasket comes with the thermostat normally)

replacement is an easy DIY but you'll need to either save your coolant by draining it into a clean container or replace it. If replacing the coolant, it's wise to flush the system. instructions can be found on a good bottle of coolant flush