Overheating Headgasket?

[General Lee]

Hi,

I have an overheating problem on my 1.2 nova, and i was told a while ago that it is most probably the headgasket. The main reason being both pipes going to and from the rad are under very high presure and really really hot, is this true?

Also why would a headgasket failure cause the engine to over heat?

Any help Would be appreciated, just want to understand how the headgasket failing causes overheating!

Is it due to it going in between the water way and a cylinder? causing the presure and the heating up of the pipe? or something else?

Just want to know what to look for when i take the head off?

Thanks
Nathan

[mowgli]

its more likely that the gasket is leaking, which is common. this causes massive pressurisation of the pipes, and the whole system in general. you normally don't grab them but they are at nearly boiling point as standard.

it is prudent to change the thermostat & flush the radiator. these are the main reasons for overheating.

[Stuart]

dont forget to not bother getting the head skimmed :p lol

[mowgli]

stu, you've still not brought me any proof that will change my opinion.

[Stuart]

and you have no proof the other way....

[mowgli]

only all of the engines i've ever repaired that had no pitting or damage to the head faces so they got a clean up & refitted.. including large diesel engines that have run for years without a skim...

[Pistol Pete]

I have done a few head gaskets on various car over the years. Never hand one skimmed. At most abit of wet and dry and a block over the faces, but thats it. Never caused me any grief afterwards either.

[Stuart]

and heads I've had skimmed havent failed like you imply they should :p

[Pistol Pete]

Wasnt implying anything love!!! IMO skimming is only needed if the heads warped. I.e if the car has been driven with a failing/faild gasket.

[mowgli]

my point is that a skimmed head will usually be fine.... but it isn't a necessity, and an unskimmed head will usually be fine.... thus you have just saved both time & money.

my main issue is that head gaskets rarely fail because they are at fault... something else usually causes the failure.... as in sludged up rad, failed thermostat, insufficient coolant, abuse.. etc.

[General Lee]

Do you test a thermostat by starting off having a cool thermostat and pour hot water from the ketle into a bowl with the thermostat in. and watch if it opens?

[mowgli]

yes, but it is better to actually have a pan of boiling water on the stove & lower it in.... female loved ones usually need to be out of the house when you do this

[General Lee]

Great thanks for your help Mowgli.