Punto cooling/running problem

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Thu 30 Nov 2006 16:19
Punto cooling/running problem - John D
I have a problem with our Punto 60S 1240cc 8 valve. 1998.

It started on 3 cylinders one day last week and was blowing bubbles into its coolant. I tried a can of ?K Seal?, but no use, so off came the head. No 1 had a tiny groove in the head, only about 20thou wide & deep, but it bypassed the thick section of the head gasket.
The local breaker supplied a replacement head complete with manifolds, sensors, ignition packs & camshaft. A new gasket & I?d be OK?or so I thought!

I have 2 symptoms: It runs, but seems too rich?on the verge of hunting. Also the engine gets hot after barely 5 mins running (the overtemp warning light comes on).

I?ve checked for poor connections, leaking vacuum pipes and changed the coolant thermistor for my original one. I?ve also made sure the cooling system is bled using the 2 bleed valves on the radiator & heater hose. The only fault I?ve found is an apparently open circuit cooling fan switch (on the radiator). This might well have been the start of the original problem, but I wouldn?t expect the engine to need the cooling fan within 5 mins of a cold start.

Can anyone throw some light on this please? Have I done something elementary & daft?

John
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Thu 30 Nov 2006 16:50
Punto cooling/running problem - local yokel
try www.fiatforum.com - they know more about Punto HGF than most.....
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Thu 30 Nov 2006 17:16
Punto cooling/running problem - bell boy
how do you know the replacement head was a good one? breakers wont normally take the head off a good engine.
Are you sure the replacement thermostat is a good one? ie new and working? they have been known to be faulty from new so i always stick them in a cup of boiling water before i ever fit them
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Thu 30 Nov 2006 22:22
Punto cooling/running problem - John D
The fiatforum led me to the temp gauge sender (on the donor head) as distinct from an overtemp switch which mine has. I've now swapped the senders.

I also removed and boiled the thermostat, which was fine. I think I was a bit paranoid about cooking an engine I'd just repaired!

About that head...we've got a proper old fashioned scrappie where you strip off what you want, so I took it off the donor car myself. He only charged me £30 but I wondered if I should have just bought the complete engine.

Current situation: I've had it running for about half an hour, and been up the road in it several times. Power is normal, but although the hunting has settled somewhat, it still ticks over with an uneven burble rather than a steady note. I didn't decoke the donor head before fitting it, and wonder if maybe oil soaked carbon might take a while to dry out? Any thoughts? I also wondered what effect it would have if I'd got the cambelt a tooth out?

I'll risk taking it into town tomorrow & see how things develop.

Many thanks

John
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