Pressurised Cooling System

krzracingcouk · 28-08-07, 08:32 PM

Hi All,

I am driving a 1982 Audi Coupe GT5S and have an interesting problem.

When driving for more than 5 to 10 minutes the cooling system is boiling and as a result pressurised. This I believe has lead to the radiator failing.

I have started the engine with the cap off the water bottle and there are no signs of a leaking head.

Any help on this or ideas would be much appreciated.

amanda · 28-08-07, 09:50 PM

thermosat

Coxy · 28-08-07, 10:11 PM

Could be an air lock in your system as well.

Try running it with the thermostat out and see if it does anything. It will take longer to warm but if the thermostat is shot then that could be the route of the problem.

Stu67 · 29-08-07, 08:09 AM

As coxy said could very well be an airlock, 5 cylinders are bad for this if not properly drained and refilled. My dads 5 cylinder santana we used to have to jack right up at the front to effectivly refill it, could never bleed it properly?? Yet his 100 turbo was fine?

krzracingcouk · 29-08-07, 11:35 AM

Hi guys,

Thank you for your help on this, I have already tried the thermosat. I ran without it, and have put a new one in it. Still the same.

If I run with the heater on full heat then things are better but still not perfect, just takes longer.

I am kinda thinking along the lines of either a air pocket (if so HELP....) or something to do with the bottom block distorting as engine warms up (had head skimmed when head gasket went).

I love my Coupe and want to get it all well again so any help would be great.

Gordon WR · 01-09-07, 06:29 AM

You may find this helpful
http://www.quattroforum.com/forum/sh...light=radiator

knobstar · 14-09-07, 10:31 AM

Very helpful instructions from that link Gordon, thank you - I'm picking up a GT5S on saturday and this is one thing (as well as changing the oil) that I intend doing before setting off home!

Matt

29-08-07, 11:35 AM	#5
krzracingcouk Grown up member Classic Audi Club Member Join Date: Aug 2007 Location: Plympton, Plymouth Posts: 471	Hi guys, Thank you for your help on this, I have already tried the thermosat. I ran without it, and have put a new one in it. Still the same. If I run with the heater on full heat then things are better but still not perfect, just takes longer. I am kinda thinking along the lines of either a air pocket (if so HELP....) or something to do with the bottom block distorting as engine warms up (had head skimmed when head gasket went). I love my Coupe and want to get it all well again so any help would be great. __________________ Audi = Acceleration Under Demonic Infulence Current Car - Audi Coupe GT 5S 1982 Model Mark 1 Been in the family now for 30+ years. Restoration Thread Also Weekend Cars - Audi A4 Touring Car, Audi A4 DTM

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Emissions system	vag80	Engine	12	14-11-09 07:29 PM
Hyraulic System Help!	djb1607	Suspension & Brakes	2	01-11-09 10:33 PM
cooling system header tank	ChrisG	Engine	13	08-03-09 03:48 PM
Fuel system in my GT..?	moomin	Engine	1	24-08-08 08:19 PM
Cooling...	randall977	Engine	9	20-06-08 12:39 PM

28-08-07, 09:50 PM	#2
amanda quattro hussie!! Classic Audi Club Member Join Date: Jul 2007 Location: doin' it on all fours!! Posts: 5,993	thermosat

28-08-07, 10:11 PM	#3
Coxy 4 Ring Mafia Classic Audi Club Member Join Date: Jul 2007 Location: on the side of a hill in Shropshire! Posts: 28,215	Could be an air lock in your system as well. Try running it with the thermostat out and see if it does anything. It will take longer to warm but if the thermostat is shot then that could be the route of the problem.

29-08-07, 08:09 AM	#4
Stu67 Grown up member Join Date: Jul 2007 Posts: 117	As coxy said could very well be an airlock, 5 cylinders are bad for this if not properly drained and refilled. My dads 5 cylinder santana we used to have to jack right up at the front to effectivly refill it, could never bleed it properly?? Yet his 100 turbo was fine?

01-09-07, 06:29 AM	#6
Gordon WR Grown up member Classic Audi Club Member Join Date: Jul 2007 Location: Chester Posts: 781	You may find this helpful http://www.quattroforum.com/forum/sh...light=radiator

14-09-07, 10:31 AM	#7
knobstar Grown up member Classic Audi Club Member Join Date: Sep 2007 Posts: 253	Very helpful instructions from that link Gordon, thank you - I'm picking up a GT5S on saturday and this is one thing (as well as changing the oil) that I intend doing before setting off home! Matt