mk2 golf coolant issue

[DeathStar]

not my gti but my 1.6 carb 4+E CL  CL... Feel the specfication! 

anyways. bizzare problem.

start it up from cold. car warms up very quick. but the heaters are blowing cold too lukewarmish... then the temp is 3/4 the way through the gauge.

but the electric fan is not comming on. and the bottom hose to the rad is cold... 

sometimes while driving the water low light will flash. only for a second

while doing this. it drips water out of the the rad and flows hot water back to the expantion tank via the expantion house at the top of the rad.

you leave the top off the expantion tank for a while and steam starts to build. and build.. and then hot hot water gushes out of the expantion tank... the fan then kicks in and the bottom hose is hot. 

seeing these symtoms just now i changed the thermosat and gave it a go. the problem is the same .

could it be to do with the heater bypass valve or maybe a matrix issue?

many thanks guys

james

[Agreeable Slick]

More than likely an air lock in the system still from changing the thermostat, fan switch could be knackered if it is a two stage one, so to that it won't kick in till it reaches the higher temp.

[DeathStar]

you would think it was an air lock however this was happening beforehand.


it is an intemittant issue too.

[Agreeable Slick]

You might have had the lock before hand.

[turbodub]

I concur. It sounds very much like an air lock. 

Get the car up to temp and then squeeze all the coolant pipes topping up the expansion tank as neccessary. Bottom rad hose needs to be hot (thermostat open) to get an accurate reading. 

[Thom89]

As the above statements say...  though make sure the the radiator isnt blocked! try flushing it through with a hose pipe, and then backflush, if its obvious that it is blocked, get a bucket of hot water, with a mug full of non biolgical washing powder, mix and pour slowly into the radiator (No joke!) any gunk left in there will have no chance.. infact the entire cooling system can be treated to this, works wonders! just be sure to flush it all out before re antifreezeing
Tom

[NuTTs]

As the above statements say...  though make sure the the radiator isnt blocked! try flushing it through with a hose pipe, and then backflush, if its obvious that it is blocked, get a bucket of hot water, with a mug full of non biolgical washing powder, mix and pour slowly into the radiator (No joke!) any gunk left in there will have no chance.. infact the entire cooling system can be treated to this, works wonders! just be sure to flush it all out before re antifreezeing
Tom

I have the same problem on my 8v GTI.. I thought the thermostat may be siezed shut, could this be a possible cause?

Also, when I partially emtied the cooling system to change a hose, a mayonaise like substance came out of the radiator top hose and this stuff is constantly coming out of the expansion tank. I've checked the engine oil and there is no water contamination in the oil. Very weird.

Anyway, sorry for the threadjack.

Regards,
NuTTs

[rubjonny]

NuTTs: It sounds to me like your oil cooler has died, I had exactly the same problem!
Replace it, then fill the system up with plain water, and dump a cupfull of biological washing powder in there.  Run the engine till the thermostat opens, then allow it to cool, and drain the coolant out.  Then flush it all out with a hosepipe, and repeat till you're happy all the oil has been removed.  Then fill it back up with a 50:50 mix of water & antifreeze.

[NuTTs]

NuTTs: It sounds to me like your oil cooler has died, I had exactly the same problem!
Replace it, then fill the system up with plain water, and dump a cupfull of biological washing powder in there.  Run the engine till the thermostat opens, then allow it to cool, and drain the coolant out.  Then flush it all out with a hosepipe, and repeat till you're happy all the oil has been removed.  Then fill it back up with a 50:50 mix of water & antifreeze.

Hi Rubjonny, thanks for the tip - I´ll give it a shot. I´m up to paitence limit with this car. It has blown 3 different radiator coolant hoses in 2 weeks and I can´t seem to be able to get all the coolant system bled correctly. I need this car working asap and my wife and I are even thinking of junking it 

I´ll do a search and see what the archives hold!

Regards,
NuTTs

[rubjonny]

My coolant bleed method:
Run the engine from cold with the cap off
Squeeze every rubber hose you can lay your hands on
Every now & again rev the engine to 2k
Keep the coolant topped up to max

Keep doing this untill the pipes get too hot to touch, and/or the coolant boils over.  At this point stop the car, and replace the header tank cap.

When you rev the car, make sure coolant is flowing out the small overflow pipe to the top of the header tank

Oh and replace your header tank cap, old ones either dont seal well, or don't vent when they are supposed to.  Make sure you use a 50/50 mix of antifreeze as well