Technical Cinquecento overheating

[Darren W]

Have gone through many posts about overheating and followed the advice given but still no joy.

The car runs for 5 - 10 minutes before the little light comes on to tell me it's overheating.

The fan didn't cut in so I replaced the cooling fan sensor which still didn't make the fan work. I bridged the fan connection with a paperclip and the fan worked perfectly and the paperclip didn't get hot. I then borrowed a multimeter from a mate to test the connections and got 12.5v from the live side and 0 from the earth. Thats about the extent of my electrical abilities

After some more research on this forum I replaced the thermostat (because the radiator wasn't getting hot). The radiator now gets very hot but the fan still doesn't kick in.

I also noticed that the pipes were soft so I soaked the header cap overnight. This seems to have worked as the pipes now get a bit harder as it heats up (but not rock hard).

I have bled the system and water trickles out of the bleed pipe. Should it be gushing out?

I don't appear to be losing any water but there is slight mayonaising in the oil filler cap.

I have run out of things to try so any help would be greatly appreciated. Many thanks in advance.

 

[Darren W]

UPDATE

Have just run car until overheating then put paperclip over fan connections but even with the fan running the car is still overheating! As mentioned, the water pipes do not get rock hard. Any ideas?

Have re-bled the system while hot and water was gushing out so can confidently say there isa no air in system.

I am really stuck and don't know what to do so any help would be greatfully received.

 

[rallycinq]

You say you are not losing water but that its overheating.

Does that mean the light is coming on, but no water is hissing out of the cap?

Cheers

SPD

 

[Darren W]

That's correct. The light does come on but no water hisses out of the cap.

Cheers.

 

[rallycinq]

Ever thought the sender might be faulty, or the wrong one.

Have you had the car for long?

Cheers

SPD

 

[Darren W]

Had the car 8 months, did an engine replacement 6 months ago. Started getting the overheating light come on over the last few months.

Ever thought the sender might be faulty, or the wrong one.

I don't know what a sender is. Do you mean the coolant temperature sensor in the thermostat housing?

 

[rallycinq]

Had the car 8 months, did an engine replacement 6 months ago. Started getting the overheating light come on over the last few months.

I don't know what a sender is. Do you mean the coolant temperature sensor in the thermostat housing?

If you don't know what a sender is, although you are right about it being the thing in the thermostat housing, did you use the sender off your old engine or the replacment?

Cheers

SPD

 

[Darren W]

Used sender unit from original engine.
Thanks.

 

[rallycinq]

Used sender unit from original engine.
Thanks.

Ok, that rules that one out, but do check it, just in case.

You haven't changed the instruments, have you?

Cheers

SPD

 

[Darren W]

No, haven't changed the instruments.
Thanks

 

[rallycinq]

Test the sender then.

Cheers

SPD