Bloke at Toad industries has a 1.3 Fiesta that's getting hot under the collar.
Symptoms: Temp goes *way* higher than usual high but turning the heater on helps.[1]
Fan stays off because the radiator is cool to the touch.
Plenty of water. It's got a bit of rust in it.
I think either there's a blockage or the thermostat is stuck closed.
My proposal is to whip the thermostat out and leave it out and flush the system as best I can.
Anybody got anything to add?
[1] He hasn't let it get into the red yet.
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These are my own opinions, and not necessarily those of all Toads.
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Bit rough when you're driven to the safety of technical Toad!
Well you know what I'm going to say...drain, flush, fit new stat and re-fill with 40% glycol mix.
MM
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Bit rough when you're driven to the safety of technical Toad!
I prefer it here, just rarely have anything useful to add to it! ;-)
Well you know what I'm going to say...drain, flush, fit new stat and re-fill with 40% glycol mix.
Yeah. Unfortunately despite detailed quizing on the circumstances of the *first* overheating it transpires that the first time it got hot was in a 15 minute traffic queue.
Now I'm thinking it's more likely to be a non functioning fan causing overheating which knackered the head gasket and put an air block in rather than a physical block.
On the plus side it appears not to be losing water in large quanities.
I'm happy to whip out thermostat. Head gaskets I really don't fancy.
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These are my own opinions, and not necessarily those of all Toads.
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Toad
I assume this is the pushrod 1.3. These have an electric cooling fan, with the 'stat on top of the thermostat housing. Usually cuts in about 3/4 of the way up the white section of the scale - should not hit the red.
They are not normally prone to air locks - I've always just filled them up, given them a run and topped up the header tank.
If it is the head gasket, then this is one of the easiest engines available to do this job on.
Regards
John S
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I was going to ask if it was just the gauge, but if turning the fan on makes a difference, then it almost certainly isn't
in which case - follow the MM way
I have to grow old - but I don't have to grow up
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Is the switch for the fan in the Rad or above the thermostat ? If it's in the rad then it might be blocked i.e. not allowing the hot water to set the switch off. you should be able to tell if the thermostat is working by feeling the heat change through the hose,by running it from cold to hot. Radiator should be hot all over. Only once in 20 years have I found the blades of the water pump fallen off. Sent me up the garden path finding that one !
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If the radiator is cold, then i suspect the water pump, as it is not pumping hot water into the rad, then the fan wont come on to cool the radiator.
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Thanks to all:
Water pump: I wondered about that but the pump itself but the belt isn't slipping. *Surely* the fins will be ok?
John S: If the fan thermostat is on top of the stat housing then the fan should come on when the thermostat is hot - i.e. even if the stat is permanantly closed.
The rad is permanently cold even when the engine is hot so there is a blockage of some kind.
The info from the gauges is correct. The hot air blows very hot and the rad is cold.
I hope this isn't the gasket. On a positive note it's getting 5-10 mins use twice a day with no ill effects.
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These are my own opinions, and not necessarily those of all Toads.
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Toad,
If the heater is blowing hot strongly, and this lowers the temp, the water pump is almost certainly OK. It will be the thermostat. Proabably only a 15 min job to whip it out on a Fiesta to see if this cures the problem (it will go the other way and run too cool). Driving it in this condition is not the best plan, as they are running a risk of cooking the engine, and a £15 job will become a £150 one...
RichardW
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Toad, If the heater is blowing hot strongly, and this lowers the temp, the water pump is almost certainly OK.
Great!
Driving it in this condition is not the best plan, as they are running a risk of cooking the engine, and a £15 job will become a £150 one...
I've told him that but people won't see reason. I also suggested removing the thermostat. He won't cos it'll be less efficient. FFS what more important Efficiency or cooking the gasket?
Can we rule out the head gasket? It's running fine and there have been no dramatic symptoms.
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These are my own opinions, and not necessarily those of all Toads.
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Toad
The heater supply comes off the block before the thermostat, and bypasses the radiator. This gives a quicker heater output after a cold start. So, good heater and cold radiator are quite feasible.
I believe the temperature gauge sender is on the head, beneath the thermostat. So, sounds more like a failed thermostat than anything else. There will be some leakage past a closed 'stat, but whether this will be enoughto trigger the fan switch, I'm not sure.
Regards
John S
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Toad,
With a cold rad then thermostat replacement first old boy before you even worry about anything else...as everyone else says.
Don't do too much work on it though, it's only a blokes car.
MM
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...unless of course you're trying to pull his wife/girlfriend/daughter/cousin/auntie/mother/pet frog??!!
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Middleman: Thanks for the reality check! I have too much imagination. Worry about one thing at a time!
Andy S: I have a hard enough time trying to pull unattached tottie without raising the hurdle!!!
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These are my own opinions, and not necessarily those of all Toads.
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Car is fixed now by the owner!
It was the 'stat and we have a new fan of HJ's site to show for it.
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These are my own opinions, and not necessarily those of all Toads.
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