205 1.4, Whats The Bit On The Top Of The Radiator?

[weejimmy 1]

hey i dont have a pic so ill try explain,

on the 1.4 205 rad theres a bit on the top at passanger side, its kind of like a rad cap that has a nut as part of it on the top.

it says "do not open" on it,

is this a preasure release cap or just a normal cap?

and dose anyone have a spare?

 

cheers

[miamichris 9]

hey i dont have a pic so ill try explain,

on the 1.4 205 rad theres a bit on the top at passanger side, its kind of like a rad cap that has a nut as part of it on the top.

it says "do not open" on it,

is this a preasure release cap or just a normal cap?

and dose anyone have a spare?

 

cheers

 

Its the radiator filling cap, open it slowly though as there may be pressure, if you undo your expansion tank cap first this will help release the pressure before you open it.

 

I haven't a spare no but I can't see them costing a fortune for a new one from the dealer.

[swordfish210 20]

You use it to initially fill the cooling system after you have drained it. Once the radiator is full you can fill the rest up through the header tank.

 

Damn, Chris types faster than me

Edited September 18, 2010 by swordfish210

[weejimmy 1]

well ill enlighten you a bit more on the story,

the misses bought the car in london, we live in edinburgh,

so got her uncle to pick it up, on the way home (30 miles away) the cap bit in question blew off.

i wonderd if it was suposed to vent at a set pressure and hadent so blew off.

whats the preasure release part on the cooling systyem then?

 

just need to cobble somthing together to drive it from london to edinburgh,

 

the head gasket is suspect on it as it was using some water, but i just thought we could keep toping it up till it got here,

its geting a new engine anyway

[miamichris 9]

well ill enlighten you a bit more on the story,

the misses bought the car in london, we live in edinburgh,

so got her uncle to pick it up, on the way home (30 miles away) the cap bit in question blew off.

i wonderd if it was suposed to vent at a set pressure and hadent so blew off.

whats the preasure release part on the cooling systyem then?

 

just need to cobble somthing together to drive it from london to edinburgh,

 

the head gasket is suspect on it as it was using some water, but i just thought we could keep toping it up till it got here,

its geting a new engine anyway

 

Well if it blew the radiator cap off, i'd definitely be suspecting the headgasket! Or possibly an air lock in the cooling system, but if you say it's using water then the HG is more likely. I'm not sure whether they vent a certain pressure, I don't think they do but can anyone else enlighten on this?

Edited September 18, 2010 by miamichris

[Lan 24 1 Cars]

a good first question would be, was the cap properly screwed on in the first place? even if the headgasket is going its no problem so quick and easy to do on tu's

[trogboy 17]

The pressure release valve on the system is the cap on the top of the expansion tank.

 

It's worth checking that the small diameter pipe between the expansion tank and the radiator is clear of sediment as they can get chogged up if the coolant hasn't been changed in a very long time. Blocking this pipe could lead to the system over pressurising.

[weejimmy 1]

went to the scrapies and got two new caps for £2

sent them down and its looking good so far,

cheers guys