pressure in coolant bottle?

[robo22sri 10]

Hey guys was wondering if i could pick your brains!?!?

 

I am having an issue with cooling the engine! i replaced the 2nd rad fan belt to get that working which has brought the temp down,

 

I have noticed that the coolant bottle is getting pressure build up but keeps the pressure when its cold! is that normal?

 

Or is this the start of the head gasket failing?

 

cheers guys

[volksworld13 0]

all engine will have pressure in the cooling system when running,this pressure allows the coolant not to boil i.e raises its boiling point, if the engine is overheating and coolant guage is high,and the header tank pressures rises alot and coolant boiles over this would indicate headgasket, head fault. seems like normal operation to me, when the engine is cold there will be slight pressure in the header tank.

Edited August 24, 2011 by volksworld13
incorrect anwser

[carrots 1]

sounds like head gasket,i had same prob

[CorradoVR6-Turbo 0]

how quickly does it pressurise ? if it does it from cold quickly its headgasket..

[VW_OwneR_85 1]

as mentioned above,the cooling system should be pressurised otherwise the fluid will boil, are you looseing coolant? if not i wouldnt worry to much, how long does it take to over heat? maybe the thermostat is stuck closed and stopping the water from circulateing through the rad?

[robo22sri 10]

Morning Folks, I bought a new thermostat last night so will change that over when I get it and see if it makes a difference

 

I will take the car for a short drive tonight and see if the expansion bottle fills with pressure when cold

 

Cheers for the pointers :)

[carrots 1]

yer worth a try,i changed the water pump next then the rad because it was a bit blocked.try your expansion cap aswell.i left takeing the head off untill last,then found out it was cracked

[robo22sri 10]

My mate at work did mention if the cap was functioning ok, ie the no return valve working on the cap

[carrots 1]

worth a try mate only a few pounds,its supposed to be blue now.i had 1 off ebay

[RW1 0]

If there's no leaks. The hoses stay hard to squeeze when cold. Then the header tank cap valve is the most likely suspect. So a good move to change this.

 

 

Don't think the thermostat would be causing. Plus changing, often as not, the housing is brittle and breaks and as the cross feed pipe from the water pump. So handle these carefully if you go down that route.

 

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[robo22sri 10]

My car has a mk4 golf coolant bottle on it

[robo22sri 10]

Little update!

 

The coolant hoses do not stay hard when cold! And when you squeeze them you can hear air moving around the coolant pipes!?!?

 

I un did the coolant bottle lid and got the air noise and the coolant level went up!

 

Anymore ideas?

[CorradoVR6-Turbo 0]

Sounds normal to me bud,does your car use coolant or over heat ?

[robo22sri 10]

Sounds normal to me bud,does your car use coolant or over heat ?

 

It has been getting very hot, but it didn't have the 2nd fan running because the belt was missing

I have replaced it and the temps are lower than before but are still getting up to 100c on water and 110+c on oil

And I doesnt seam to be using coolant

Edited August 28, 2011 by robo22sri

[RW1 0]

Normal :) Join the club my friend.

 

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