Hello I have coolant escaping from the expansion cap after my Punto has been running on idle for 10mins. The cap is new and there are no symptom of head gasket failure. Waited until car had cooled down and took cap off - there was quite a bit of brown sludge. If I flushed radiator would that fix the problem maybe ? An help much appreciated ! Thanks model is 04 1.2 8v

Drain the whole system

Refill with tap water.. run til hot

Then
Dump that also

Repeat until it stays clear looking..

Does the radiator fan work?

mrnolegs said:

Hello I have coolant escaping from the expansion cap after my Punto has been running on idle for 10mins. The cap is new and there are no symptom of head gasket failure. Waited until car had cooled down and took cap off - there was quite a bit of brown sludge. If I flushed radiator would that fix the problem maybe ? An help much appreciated ! Thanks model is 04 1.2 8v

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I am thinking your thermostat is broken. 10 mins on idle is not a very long time. Is the bottom radiator hose warm? Once the engine arrives at the normal temperature the top hose should get warm and progressively the whole radiator gets warmer until hot water is leaving the radiator. If the radiator is cold and the thermostat cannot open then eventually the engine water will boil and force cold/warm water out of the radiator.

Thanks so much for your replies. I’ll flush system as you advise. And also change thermostat. I’ll report back and let you know what happens ! Thank again ?

mrnolegs said:

Thanks so much for your replies. I’ll flush system as you advise. And also change thermostat. I’ll report back and let you know what happens ! Thank again ?

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You are better off testing the thermostat first. The top hose should stay cold until the engine has got quite warm. Hot water then begins to move into the radiator as the engine becomes hotter until eventually before the engine is over heating you have hot water coming out of the bottom hose back to the engine.


Flush first.

These engines are notorious for headgaskets, saying that you'd replace the thermostat when doing the headgasket anyway. If it doesn't solve it, you haven't wasted any money.

It was probably 15 years ago when my 8v blew its headgasket, you could hear a bubbling sound behind the dash when you started it up.

mrnolegs said:

Thanks so much for your replies. I’ll flush system as you advise. And also change thermostat. I’ll report back and let you know what happens ! Thank again ?

Click to expand...

Did the cooling fan work..?

Thats important

These low coolant engines are great as long as they never get low on coolant. However as there is not very much in the car, the head gasket quickly gets over-stressed. Apart from corroded rads, the steel pipe under the exhaust manifold is a common source of leaks.

Change the thermostat and run it on plain water to flush the system. When you know its ok, drain the water add the correct volume of concentrate and top up with water.

If you suspect the cylinder head get a chemical test kit.
https://www.ebay.co.uk/itm/BT-1-50m...188540&hash=item421fff0778:g:zfwAAOSwIP9fZMum

You could also have a worn water pump there