Fiat Punto Overheating

HELP!!! My wife has a 2001 "Y" Fiat Punto 1.2 8V. The problem we have is it seems to leak water out the rad cap and if the header is on cold the
temperature gauge wizzes up and the car overheats. If when the gauge starts wizzing up she moves the heater control to hot then the gauge goes back to normal. The heater works fine and there is no oil in the water to indicate a head gasket problem. I have changed the rad cap just in case but this has made no difference. Any assistance would be greatly appreciated. Regards
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There's 2 possibilities.
Worst case, it's got a blown head gasket.
Best case, it's a knackered water pump.
You need to get it pressure tested at a garage to determine which is the problem.
If it's the head gasket, have the water pump changed at the same time, because it *will* need replacing at some point very soon....
--
Steve H 'You're not a real petrolhead unless you've owned an Alfa Romeo'
http://www.italiancar.co.uk - Honda VFR800 - MZ ETZ300 - Alfa 75 TSpark
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Would also add there is the possibility of a large airlock in the radiator.
Check for bleed screws/points at the top of the radiator AND on all water hoses.
The car heater matrix is generally at a lower level than the maximum water hight in the cooling system.
Nick /////
wrote:

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Thanks, i'll check the airlock.
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What about a blocked radiator, or a knackered thermostat?
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Thanks for the quick response. If it was the head gasket would i not see signs of oil in the water? Is there a way of seing if the water pump has gone? Regards
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Oil in water is not always present.
Check for bubbles in radiator/header tank
As for water pump the only sure way is to remove it. Another method is to wait till the engine is warm, shut off the car heater controls (set to cold), and then manually restrict the top/bottom and bypass water hoses. e.g. clamp the bypass hose fully then manually squeeze the radiator hose. A point will come where noise/vibration/flow can be sensed. How you determine if this is normal or not I don't know :-) Of course higher engine revs will increase flow and 'feeling'.
I'm assuming your Punto has a header tank in which case there will be a small top return hose. This should be pushing water into the top of the header tank. Depending on the visibility of the plastic you may be able to see the varying flow with engine revs. If not you can disconnect this hose, extend it and poke it into the header tank cap hole and water the discharge rate.
These are all 'off the cuff' suggestions and may leave you in a bigger dilema than ever!
Nick /////

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I'm going from my experience of a Cinq. Sporting (1.1 version of the same FIRE lump). Initially we replaced the radiator, then the thermostat, then the fan switch, before suspecting a blown head gasket. It was cured in an afternoon of contorting myself under the bonnet to replace the waterpump and cambelt.
--
Steve H 'You're not a real petrolhead unless you've owned an Alfa Romeo'
http://www.italiancar.co.uk - Honda VFR800 - MZ ETZ300 - Alfa 75 TSpark
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