Post by lowtechguy on Feb 28, 2007 16:27:25 GMT
Headgasket Failure
Fiat Fire engined cars like puntos are prone to head gasket failures. There's no predicting when they will go, some will last for ever and some wont. The most common cause of gasket failure is corrosion inside the water passages, this creeps past the gasket and causes it to fail. Regular (i.e. annual) change of antifreeze will minimise the probability of this. Check for this in the service history when buying used. Also check your antifreeze has corrosion inhibitors in - some cheap versions don't.
Tell-tale signs vary, if yours has gone you may have one or more of the following symptoms :
1. Creamy deposit in the cam cover and under the oil filler cap, caused by water getting into the oil. This can be caused by infrequent short runs though, where the oil doesn't get up to temperature.
2. Oil in the water - smell the expansion. If it smells like exhaust gas, petrol or oil then the gasket's gone.
3. Oil or water leaks from the engine block.
4. Gradual loss of coolant with no visible cause. (e.g. max to min in a week or so, if it occurs over several months this would not neccesarily indicate a problem)
5. Misfiring when cold for the first few seconds after starting up, caused by water getting into one or more of the cylinders.
6. Persistent misfires, especially when using heavy throttle at low revs caused by leakage from the cylinder past the head gasket.
7. Overheating (See below for more information)
Costs to repair can vary, budget on around £200-300 for a garage or £100 to do the job yourself, as the head is alloy and it will need skimming in a machine shop at a cost of around £30-40.
Things need to be changed when doing the work are:
- Spark plugs
- Oil
- Oil filter
- Coolant
- Timing belt and tensioner
- Gasket set (headgasket, inlet, exhaust gaskets etc)
- Head bolts (they stretch and can’t be re-used)
- Thermostat
- Fanswitch
- Water pump (possibly)
Overheating
As with virtually any car, puntos can suffer with overheating, but our little cars run quite hot anyway - it's normal for the cooling fan to cut in and out every 30 seconds or so when stuck in queue traffic. If it is overheating, a few possible causes are:
1. Loss of pressure in cooling system - the water needs to be pressurised to raise its boiling point, otherwise localised boiling can occur inside the water passages - this can be caused by leaks or a faulty expansion bottle cap (£3 from Halfords).
2. Radiator - Sadly, radiators don't last too long either, average 4 years or less for a steel one. You can have the tiniest of pin holes which can be really difficult to locate.
3. The Heater matrix – this can leak.
4. Fan - If the little cooling fins are rotten or missing on the radiator fan, the efficiency will be greatly reduced and can also contribute to overheating. The most common cause of fan failure is the siezure of the motor, spin the fan with your hand and it SHOULD turn very freely, if there is resistance there then its on it's way out. If you cant move it very well, time for a new fan!
5. Electrical failure -The fan switch or fan itself can fail, robbing your car of that extra air flow over the radiator.
6. Muck! It could be in need of a radiator flush.
7. Failed thermostat - about £12 each, when they go they can stick open (at least you'd still be able to drive home) or closed (it'll boil over).
8. The Dreaded Head Gasket – see above.
9. Excessively low oil or water levels. (e.g. way under the min mark)
Fiat Fire engined cars like puntos are prone to head gasket failures. There's no predicting when they will go, some will last for ever and some wont. The most common cause of gasket failure is corrosion inside the water passages, this creeps past the gasket and causes it to fail. Regular (i.e. annual) change of antifreeze will minimise the probability of this. Check for this in the service history when buying used. Also check your antifreeze has corrosion inhibitors in - some cheap versions don't.
Tell-tale signs vary, if yours has gone you may have one or more of the following symptoms :
1. Creamy deposit in the cam cover and under the oil filler cap, caused by water getting into the oil. This can be caused by infrequent short runs though, where the oil doesn't get up to temperature.
2. Oil in the water - smell the expansion. If it smells like exhaust gas, petrol or oil then the gasket's gone.
3. Oil or water leaks from the engine block.
4. Gradual loss of coolant with no visible cause. (e.g. max to min in a week or so, if it occurs over several months this would not neccesarily indicate a problem)
5. Misfiring when cold for the first few seconds after starting up, caused by water getting into one or more of the cylinders.
6. Persistent misfires, especially when using heavy throttle at low revs caused by leakage from the cylinder past the head gasket.
7. Overheating (See below for more information)
Costs to repair can vary, budget on around £200-300 for a garage or £100 to do the job yourself, as the head is alloy and it will need skimming in a machine shop at a cost of around £30-40.
Things need to be changed when doing the work are:
- Spark plugs
- Oil
- Oil filter
- Coolant
- Timing belt and tensioner
- Gasket set (headgasket, inlet, exhaust gaskets etc)
- Head bolts (they stretch and can’t be re-used)
- Thermostat
- Fanswitch
- Water pump (possibly)
Overheating
As with virtually any car, puntos can suffer with overheating, but our little cars run quite hot anyway - it's normal for the cooling fan to cut in and out every 30 seconds or so when stuck in queue traffic. If it is overheating, a few possible causes are:
1. Loss of pressure in cooling system - the water needs to be pressurised to raise its boiling point, otherwise localised boiling can occur inside the water passages - this can be caused by leaks or a faulty expansion bottle cap (£3 from Halfords).
2. Radiator - Sadly, radiators don't last too long either, average 4 years or less for a steel one. You can have the tiniest of pin holes which can be really difficult to locate.
3. The Heater matrix – this can leak.
4. Fan - If the little cooling fins are rotten or missing on the radiator fan, the efficiency will be greatly reduced and can also contribute to overheating. The most common cause of fan failure is the siezure of the motor, spin the fan with your hand and it SHOULD turn very freely, if there is resistance there then its on it's way out. If you cant move it very well, time for a new fan!
5. Electrical failure -The fan switch or fan itself can fail, robbing your car of that extra air flow over the radiator.
6. Muck! It could be in need of a radiator flush.
7. Failed thermostat - about £12 each, when they go they can stick open (at least you'd still be able to drive home) or closed (it'll boil over).
8. The Dreaded Head Gasket – see above.
9. Excessively low oil or water levels. (e.g. way under the min mark)