Overheating problem.

[NobleGuy]

This is for my wife's Fiat but you lot are so good with your diagnoses and tips that I'd try you out. (Plus the Fiat forum is like a graveyard :-).) Wife's car today overheated to maximum guage level and I found there was almost no coolant in the system. Spent around 2 hours chucking in pure tap water and finding the spout for the coolant was acting like a geyser, and the radiator sounded like an old central heating system knocking away. So I assumed their was loads of air in the system and continued running it, shutting it down, bleeding the radiator and got a load of air out. The heater had also stopped working andwas only blowing cold.

Went for a drive just now and it stayed on medium temp for about 3 or 4 minutes, then shot up really high again. Coasted for about a minute and the temp returned to normal/medium. Drove again and the temp went straight back up. Heater is now blowing hot (well searing) air. Do I just need to fill the system now with coolant rather than pure water (it looks like the water is circulating since the heater is working and the water coming out of the radiator when I just bled it again was hot - earlier it was cold), or is this something a bit more sinister?

[D_G]

I wouldn't put cold water into a hot engine, it probably gushed out because it boiled on contact. You can try to top it up cold and bleed it, but I would get it pressure and block tested next, deffo seems theres a problem (or it will tell you).

HTH

Dave

[JLSELAN]

Almost certainly a failed head gasket--and most likely a warped head. Sorry.

[NobleGuy]

Not the Fiat! Noooooo.......

[joust]

JLSELAN said:

Almost certainly a failed head gasket--and most likely a warped head. Sorry.

Sounds like the water is boiling in the head and creating air locks. Not good news I'm afraid.

J

[Ash M400]

joust said:

JLSELAN said:

Almost certainly a failed head gasket--and most likely a warped head. Sorry.

Sounds like the water is boiling in the head and creating air locks. Not good news I'm afraid.

J

[sean_goodman]

you sure the water is being pumped around the system?

water boiling
no heater

might be worth checking water pump

also check thermostat isnt stuck shut, you could take it out and run without it for a while as a test it would just take longer to heat up to temp without it.

check the small easy things before thinking the worst,

to fill system, fill it up, leave the cap off and run til the fans kick in, that should have let most of the air work its way out. put cap on and test drive

also if head gasket has blown i would expect to see white smokey exhaust or white gunge in the engine oil

[NobleGuy]

Yes, gunge in the oil is a common sign, but that hasn't as yet shown up. Wifey said she saw white smoke once as she was pulling away, but not before that and not since. Heater is now working having refilled with water. Also starts well which it didn't before.

Water certainly wasn't going round the system initially but it is now. I drove it to work this morning but it's only a 5 minute drive so not much of a test really, although the temperature did remain normal.

Don't suppose anybody knows where the thermostat would be or what it looks like?

P.S. wifey mentioned that the fuel consumption was higher than normal, which is another sign - she then told me last night that she simply forgot to fill up last week so maybe the fuel consumption is a bit of red-herring.

Edited by NobleGuy on Tuesday 16th October 17:08