kebab
Member
At my time working at a main dealer ive seen my fair share of headgasgets gone on puntos, at a guess aprox 1 a week for 5 years on average.
Since its one of the most common faults on the puntos engine i thought i would put together a short post on my favorite simptoms and methods for diagnosing this fault.
NOTE, this guide is only applicable to:
MK1 punto 55
MK1 punto 60
MK1 punto 75
Mk2 punto 60
Cinqucento sporting
There are other models that can be covered by these simptoms and methods, i just listed the most common.
1.)Block tester. Rather than using intuition and skill use this little piece of equipment to tell you if the sucker has gone, effectivly a container of liquid which changes colour when gasses containing hydrocarbons are bubbled through it. Placed ontop of the coolant tank a small hand pump sucks gasses from the coolant tank through the liquid, If your gasget is leaking gasses into the coolant it will give a clear indication.
2.)Vehicle runs on 3 cylinders when cold but clears after a short while.
classic punto headgasget simptom caused by coolant leaking into the cylinder, as the problem becomes worse this simptom becomes a slight missfire to full blown runs on 3 all the time.
I find the slight missfire is best felt by placing your hand in the path of the exhaust tail pipe so you can feel the ocasional missed puff of steam.
3.)Excessive steam. that white stuff coming out of your tail pipe is mostly steam, missing coolant from a failed headgasget finds it way here. This is not a very consistent way to diagnose a failed headgasget but it can sometimes be a tell tail sign.
4.)Air in the cooling system. Well not air but induction and exhaust gasses, firstly put your heater onto maximum too bleed out the air, take off the rad cap fill too brim! with water, remove rad bleed screw, bleed the system, replace screw, topup rad too brim again, remove the back bleed screw, bleed all air, replace screw, top up too brim again, now start engine with cap off and leave it running toping up the coolant as needed untill the rad fan cuts in (note if the gasget it too far gone this wont happen, it will just boil over) after the fan has cut out give the engine some revs, the water level should drop a little, top it up again too the brim and inspect the coolant, a failed gasget will produce lots of air bubbles which are easy to spot if you know what your are looking for. this is a really good method although it requires a bit of experience.
5.)Just drove the car into the workshop, upon opening the rad cap there is a extra long hiss and glug from the cooling system.
Classic headgasget simptom caused by a build up of combustion gasses in the cooling system, an experienced tech will quickly smell the coolant while these gasses are still about, a leak can be quite ovious with experince just from the smell.
6.)Compression test. This wont tell you much, if your engine has low compressions to start with the test can be quite inconclusive.
7.)Cylinder leakage test. Much better results, fills the cylinder with compressed air while the engine is set to tdc on that cylinder, lots of a drop of pressure and bubbles should be seen in the coolant if the gasget has failed.
8.)Inspect the piston. Simple enough, when the headgasget fails it nearly allways cleans all the carbon of the piston crown on the offending cylinder, pull out the plug on the suspect cylinder and have a look at the crown, if one is far cleaner than the others then its a good chance thats the one.
tips:-
Punto headgasgets tend to fail on no.1 cylinder or ocasionally no.4 so check these cylinders first.
Water leaking into the oil and causing the mayo effect is not something you see in puntos although you should expect to see a little of this in the cap, its mearly the product of oil and water vapor in the atmosphere.
Mayo mainly occours when a overhead valve engines headgasget fails between the water jacket and the chamber the push rods run it, this causes a direct leak of water into the sump filling the engine with mayo, lots of it!!!
This cannot happen on a punto as there is only one tiny oilway between the sump and cams.
If you do the headgasget on your own double check you put the gasget on the right way around because it is possible to fit upside down which does stop oil from reaching the camshaft and can be expensive, ive seen it done too many times.
If you overheated your engine be warned you almost of certainly have damaged your stat and or temperature guage sender unit, your guage may read wrong and the engine may run cool if they are not replaced, be warned.
If you think you gasget my be on the way out what ever you do dont put antifreeze in it, not only is it wasted down the exhaust pipe ive allways found that it makes the problem even worse.
forgive my spelling mistakes and bad grammer
Since its one of the most common faults on the puntos engine i thought i would put together a short post on my favorite simptoms and methods for diagnosing this fault.
NOTE, this guide is only applicable to:
MK1 punto 55
MK1 punto 60
MK1 punto 75
Mk2 punto 60
Cinqucento sporting
There are other models that can be covered by these simptoms and methods, i just listed the most common.
1.)Block tester. Rather than using intuition and skill use this little piece of equipment to tell you if the sucker has gone, effectivly a container of liquid which changes colour when gasses containing hydrocarbons are bubbled through it. Placed ontop of the coolant tank a small hand pump sucks gasses from the coolant tank through the liquid, If your gasget is leaking gasses into the coolant it will give a clear indication.
2.)Vehicle runs on 3 cylinders when cold but clears after a short while.
classic punto headgasget simptom caused by coolant leaking into the cylinder, as the problem becomes worse this simptom becomes a slight missfire to full blown runs on 3 all the time.
I find the slight missfire is best felt by placing your hand in the path of the exhaust tail pipe so you can feel the ocasional missed puff of steam.
3.)Excessive steam. that white stuff coming out of your tail pipe is mostly steam, missing coolant from a failed headgasget finds it way here. This is not a very consistent way to diagnose a failed headgasget but it can sometimes be a tell tail sign.
4.)Air in the cooling system. Well not air but induction and exhaust gasses, firstly put your heater onto maximum too bleed out the air, take off the rad cap fill too brim! with water, remove rad bleed screw, bleed the system, replace screw, topup rad too brim again, remove the back bleed screw, bleed all air, replace screw, top up too brim again, now start engine with cap off and leave it running toping up the coolant as needed untill the rad fan cuts in (note if the gasget it too far gone this wont happen, it will just boil over) after the fan has cut out give the engine some revs, the water level should drop a little, top it up again too the brim and inspect the coolant, a failed gasget will produce lots of air bubbles which are easy to spot if you know what your are looking for. this is a really good method although it requires a bit of experience.
5.)Just drove the car into the workshop, upon opening the rad cap there is a extra long hiss and glug from the cooling system.
Classic headgasget simptom caused by a build up of combustion gasses in the cooling system, an experienced tech will quickly smell the coolant while these gasses are still about, a leak can be quite ovious with experince just from the smell.
6.)Compression test. This wont tell you much, if your engine has low compressions to start with the test can be quite inconclusive.
7.)Cylinder leakage test. Much better results, fills the cylinder with compressed air while the engine is set to tdc on that cylinder, lots of a drop of pressure and bubbles should be seen in the coolant if the gasget has failed.
8.)Inspect the piston. Simple enough, when the headgasget fails it nearly allways cleans all the carbon of the piston crown on the offending cylinder, pull out the plug on the suspect cylinder and have a look at the crown, if one is far cleaner than the others then its a good chance thats the one.
tips:-
Punto headgasgets tend to fail on no.1 cylinder or ocasionally no.4 so check these cylinders first.
Water leaking into the oil and causing the mayo effect is not something you see in puntos although you should expect to see a little of this in the cap, its mearly the product of oil and water vapor in the atmosphere.
Mayo mainly occours when a overhead valve engines headgasget fails between the water jacket and the chamber the push rods run it, this causes a direct leak of water into the sump filling the engine with mayo, lots of it!!!
This cannot happen on a punto as there is only one tiny oilway between the sump and cams.
If you do the headgasget on your own double check you put the gasget on the right way around because it is possible to fit upside down which does stop oil from reaching the camshaft and can be expensive, ive seen it done too many times.
If you overheated your engine be warned you almost of certainly have damaged your stat and or temperature guage sender unit, your guage may read wrong and the engine may run cool if they are not replaced, be warned.
If you think you gasget my be on the way out what ever you do dont put antifreeze in it, not only is it wasted down the exhaust pipe ive allways found that it makes the problem even worse.
forgive my spelling mistakes and bad grammer
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