radiator cap came off!!!

[yellow gtir]

drove the R for a wile and then left it to cool down for a wile around 20 mins and suddenly the exhaust started to smoke rapidly (white smoke)and then i noticed the radiator cap came off from one corner and steam was coming out and could hear the water bubbling and i have fitted a water temp gauge and the when the car is being driven the temps ok but once you standing still and the car is idling the water temp starts to rise. any one got any idea what it could be??

thanks

 

[Fast Guy]

You left the car idling for 20mins?

Radiator fans not working? Water pump faulty? Water leak leading to low water level.

 

[yellow gtir]

Yep I did Leave it on for about 20 mins to let it cool down, the fan works perfectly and there are no water leaks and the level is finee...i was thinking could it be the thermostat
cheers

 

[olliecast]

if the exhaust was smoking badly, then could there be water getting in somewhere? i.e. headgasket?

 

[darkyGTI-R]

Why would you leave it to cool down for 20mins?
5 mins is fine or drive normal for the last 5 mins ie no boosting it,that's what I do!

 

[nex]

why would you leave it running for 20mins - shares in shell or bp? sounds like the fans, check your fuses etc?

 

[darkyGTI-R]

His fans are fine Ryan, petrol prices now forget that lol

 

[yellow gtir]

lol...nope its not the petrol i was feeling rich haha....but my turbo seals went which i recon'd nd replaced...so the car has been on quite abit to let all the excess oil clear out the exhaust....but i dont think its headgasket as that would have reduction in power....any ideas on thermostat going
cheers

 

[Fast Guy]

Don't leave it running like that. There's no need. It's a turbo car not a nuclear reactor on the edge of thermonuclear meltdown. You only need to drive easy (ie normal) for the last couple of mins and it's fine)
It's probably overheated through being sat there idling for 20mins.

Don't assume there's no water leaks because you haven't seen one. I've had one that dropped straight onto the exhaust and burnt off before hitting the ground. The only thing that gave it away was the sound of water gurgling after parking up.

It's possible you may have an air lock in the system if there are no leaks. It might be worth bleeding the system. It could be worth checking the thermostat* works. To do this place it in boiling water and make sure it opens.

The exhaust smoking could be signs high crankcase pressure forcing oil past the turbo seals again with prolonged idle. The seals may not be 100% or the piston rings could be worn.

*Typing error corrected. (cos you don't spell "thermostat" - "rad cap":doh

 

[yellow gtir]

yepp...the water was gurglingg after a whilee thats why i turned it off......and i replaced the rad cap to a 1.1 bar one now and has made a difference but i think most likely its got air lock in the system

 

[darkyGTI-R]

You hope anyway lol

 

[PobodY]

Do you need to be running a higher pressure in your cooling system? I toyed with the idea, but decided that the extra pressure on everything wasn't worth it; I don't boil my coolant regularly, so have no need to raise the boiling point.