On my 00 WRX RA, the bottom radiator never seems to get warm. The temp gauge sits at halfway once up to temp and the fans kick in/out as you would expect when sat idling for a while. The coolant system is free from airlocks.

I've so far replaced the radiator and the thermostat, bled the system and still no change.

Its bugging me that the bottom rad hose doesn't get warm.

Anyone have any thoughts?

Thanks, Matt.

 

Fogive me if this is a silly idea , i have not taken this part of my car apart yet , is it posible to fit thermostat in backwards , the bottom pipe should be getting warm at least if the water is up to temp and the stat is opening up, ive never really held onto the bottom pipe , will have a quick grope tonight after drive home and let you know .

 

the bottom pipe on mine will only get hot if the stat opens and the fans come on.
otherwise its always colder than the top one. if it was the same temp then the radiator wouldnt be doing its job properly of cooling the water.

 

if it aint overheating it aint broke.

 

The stat is in the correct way around, and the jiggle pin is at the top, as it should be. The bottom hose is cold all the time, even after a 2 hour run. The fans cut in, and the temp stays at half way.


The only other thing i can think of is the water pump, but if the water pump was failing and not flowing water, i would have thought the temp would rise?

I'm sure this is not right.

 

Been through this myself - there is defo nothing wrong!
The only time the bottom pipe warms is when the stat is open and that usually is only when stationery. When your moving the air keeps the temps low enough that the stat isnt fully open allowing enough hot water through. The stat works roughly around 78 - 89degrees. My PSI3 reads around 90 odd before the bottom pipe warms and ive had rad replaced thermostat and all sorts of sniffer tests etc carried out as I thought something was wrong - there wasnt!!!

Hope this makes sense? Let her tick over for a good while and the bottom pipe will get warm.

 

Cheers bud, i've never known it to get warm at all. i'll leave it running in the workshop while i'm at work tommorrow morning.