New Radiator, Overheating.

[TheReaperWaits 6 1 Cars]

Hey folks. Had an overheating problem to begin with and found that the top radiator pipe was hot while the bottom was cold. Renewed the radiator and bled the system.

 

Problem now is that both ends of the radiator pipes remain cold. I had both bleed holes open when refilling the system and closed them when a steady stream of coolant exited. Thinking it could be the thermostat. Would coolant come out of the bleed screw if it was stuck closed? Any extra tips on bleeding (read most of the old threads) as I expect there is air trapped. Somewhere too.

 

Which way does the coolant flow through the radiator?

[Slo 283 1 Cars]

Top to bottom replace the thermostat as a matter of course if it been overheating as it will be well knackered, does sound like its sticking shut. I had same problem once on my turbo and after taking it out it took a few swings with a hammer to break it open.

 

Oh and yes coolant will still come out of the bleed screws if its stuck shut since its just a simple water loop however air more than likely wont as the coolant cant circulate at the top so neither will the air trapped behind the thermostat hope this helps

Edited June 18, 2013 by Slo

[JamesE 5]

I'm by no means an expert but when I changed my rad I ran the car up to temp, left the cap off, heater on full, and opened bleed screw whilst squeezing/releasing the top hose loads. Seemed to work for me.

Edited June 18, 2013 by JamesE

[Tom Fenton 1,548]

I would change the thermostat but after that start looking at the water pump.

[TheReaperWaits 6 1 Cars]

Oh and yes coolant will still come out of the bleed screws if its stuck shut since its just a simple water loop however air more than likely wont as the coolant cant circulate at the top so neither will the air trapped behind the thermostat hope this helps

 

This is what I was wondering, thanks for clearing that up.

 

I'm by no means an expert but when I changed my rad I ran the car up to temp, left the cap off, heater on full, and opened bleed screw whilst squeezing/releasing the top hose loads. Seemed to work for me.

Will give that a go.

 

I would change the thermostat but after that start looking at the water pump.

Picking up a new thermostat tomorrow... Hoping it's not the water pump....

[Ramigojag 19 1 Cars]

id agree the problem was originally with the rad, but seeing as its got so hot probably nackered the thermostat so thats causing a problem now

[TheReaperWaits 6 1 Cars]

Picked up the new thermostat today. Fitted it, re-bled the system. All pipes get hot and the fan kicks in and keeps it cool. Job is a good'un.

 

Thanks for the help guys. :-)

[dcc 855]

What temp thermostate did you get? Ive got an 88 but not sure if thats too hot? :|

[Anthony 1,003]

88/89 degree is what most GTi's had as standard AFAIK, although I usually fit 82/83 degree ones when I replace them.

[TheReaperWaits 6 1 Cars]

Was an 82C thermostat. ;-)