massive airlock 2.4 Hilux

[xfman87]

Hi All,
I know there are numerous threads on burping surfs cooling systems but I think I have tried the majority of the suggested methods.

I have a 2.4 diesel 2l hilux LN85. I changed the thermostat (new one 88oC) cause it was stuck open. I also changed the coolant well I was there. (Im running radiator off a 5l)

I filled it up with new coolant through the radiator cap on top of the radiator and pulled off the outlet from the heater to ensure no airlocks in the heater. I drove it round the block until it heated up to normal then come home and took the radiator cap off and topped up with coolant.

I have two problems,
1) the bottom radiator hose is still cold after all this
2) it seems as if the themostat is not releasing probably cause of the airlock (i tested that it opened in boiling water)

I left it running at 2000rpm in the garage for about 20min with radiator cap off and still no themostat release.

This is really ####ing me off as a simple task has turned into a real prick, do any of you guys have any suggestions ???

[Koi]

1. Were heater controls all set to hot when filling / burping the system.
2. Is hot air coming from the heater?
3. bottom part of rad / hose will still be cold even after an hours driving, always was on my 2.4.
4. is there enough coolant in the expansion bottle?

[xfman87]

Hi

Heater controls were set to hot, and running on high, warmish air was coming from heater after letting it run for about 20min, plenty of coolant in expansion tank.

Bottom radiator hose was cold like not even warm thats why i thought there is an issue with air lock.

I just wanted to be careful not to crack the head or anything as it seems like thermostat not releasing. Thermostat housing was very hot to the touch and pressure was in heater hoses.

I have jacked up the front and will leave overnight with rad cap off to see if that helps. Any other advice would be much appreciatated

Cheers

[tweak'e]

which brand thermostat did you put in? part number?
which 2l? series one or two?
did you put the jiggle pin up the top?

sitting, even at high idle, does't put much heat into the engine. you need to drive a diesel to heat it up.

[woodwarm]

Sounds like airlock at heater matrix.

Why fill from radiator cap ?

Best to refill from heater pipes

[xfman87]

which brand thermostat did you put in? part number?
which 2l? series one or two?
did you put the jiggle pin up the top?

sitting, even at high idle, does't put much heat into the engine. you need to drive a diesel to heat it up.

I originally had a repco thermostat but returned that and went and got a genuine toyota thermostat which is 88oC. Its a 1997 2.4 diesel hilux so not sure if its a series 1 or 2 sorry.

Thermostat has spring side facing the engine if thats what you mean by jiggle pin?

I have taken it on a couple of 20min drives. It heats up to normal temperature and stays there. when i get to destination, I checked bottom hose and its still cold.

Stupid thing

[yorta2]

The little 'thing' centred right on the front of this image of a thermostat is the 'jiggle pin':

[tweak'e]

I originally had a repco thermostat but returned that and went and got a genuine toyota thermostat which is 88oC. Its a 1997 2.4 diesel hilux so not sure if its a series 1 or 2 sorry.

Thermostat has spring side facing the engine if thats what you mean by jiggle pin?

I have taken it on a couple of 20min drives. It heats up to normal temperature and stays there. when i get to destination, I checked bottom hose and its still cold.

Stupid thing

1997 will be a series 2. i'm surprised its 2.4, i would have thought they would all be 2.8's by then.
toyota thermostat starts to open at 88c. aftermarkets are fully open by 88c.

i would expect the bottom radiator hose to be fairly cool if the radiator is working well. especially if you have a bigger than standard one.

if water level is now ok then it sounds like air block has cleared.
sounds like its running ok.

tho i would fit an aftermarket temp gauge, toyota ones are fairly useless.

[Koi]

if temp gauge stays in normal position and heaters blowing hot and bottom hose is cold then I say all is good.
On my 2.4 with standard rad, bottom hose was colder even after a 1 1/2 hours drive.

[xfman87]

if temp gauge stays in normal position and heaters blowing hot and bottom hose is cold then I say all is good.
On my 2.4 with standard rad, bottom hose was colder even after a 1 1/2 hours drive.

The only reason I was concerned was because after an hour of driving around town, the bottom of radiator n bottom hose are still cold, like not even luke warm. Temp gauge has not moved from normal.

Cheers