over heating again

[shiny]

I have a 2.4 turbo 1990 G reg surf and I am experiencing some heating problems which are that when I go
for a longish drive the water goes to expansion water bottle and fills it up, if I then put back the water from the expansion
tank into main rad filler then there seems to be the right amount that i started with...for some reason it doesn't suck it up from the expansion tank
I have replaced the hose in expansion tank and it still does it, I have had the head tested for head gasket leak but was told it was ok
I also had the radiator check cleaned and tested this is ok too..am I missing something can anyone shed some light on what this problem might be and can I fix it?

thanks Shiny

[BUSHWHACKER]

You need a new rad cap.
you may as well change the thermostat as well while you're at it .

[Chillitt]

it wont 'drink' the water in the expansio bottle till it cools right down.. how long are you giving it?

[NiftyNev]

The coolant in expansion tank should only rise around 15 - 20mm when engine is at operating temperature.Any more than this may be a radiator cap not holding pressure correctly. A thermostat sticking, causing the engine to get hotter, which in turn will create more pressure or in severe cases a buggered head gasket or cracked head.Do as allready suggested and replace both thermostat and rad cap if they have not been done allready.Have a good look at the bottom seal on radiator cap.They are not made as well as they used to be and I have had to replace them before they are 12 months old.I'm trying another brand (Aunger) at the moment which has a type of urethane (?) seal rather than the rubber to see if they are better.

Neville

[joe112]

The coolant in expansion tank should only rise around 15 - 20mm when engine is at operating temperature.Any more than this may be a radiator cap not holding pressure correctly. A thermostat sticking, causing the engine to get hotter, which in turn will create more pressure or in severe cases a buggered head gasket or cracked head.Do as allready suggested and replace both thermostat and rad cap if they have not been done allready.Have a good look at the bottom seal on radiator cap.They are not made as well as they used to be and I have had to replace them before they are 12 months old.I'm trying another brand (Aunger) at the moment which has a type of urethane (?) seal rather than the rubber to see if they are better.

Neville

Neville,

I am sure I've read on here somewhere it can be beneficial to a 2.4 to take the thermostat out to help with the overheating problem - am I right on this or am I gettin my wires crossed???

Joe

[Guest]

Some do or though generally you shouldn't. The Thermostat restricts the flow of coolant making sure it doesn't circulate too fast and therfore not get rid of ot's heat efficiently.

[NiftyNev]

Neville,

I am sure I've read on here somewhere it can be beneficial to a 2.4 to take the thermostat out to help with the overheating problem - am I right on this or am I gettin my wires crossed???

Joe

Thermostats should not be removed.They are there to do the job of regulating the flow of coolant and removing will not cure overheating problems unless the thermostat itself is faulty and therefore it should be replaced.

Neville

[shiny]

thanks everyone

Thermostats should not be removed.They are there to do the job of regulating the flow of coolant and removing will not cure overheating problems unless the thermostat itself is faulty and therefore it should be replaced.

Neville

Thanks everyone I have brought a new radiator cap about 2 months ago but I will try for a new thermostat and see if that helps in anyway I guess toyota will be best bet to get this?...anyway its great to get a bit of help again many thanks..Shiny

[shiny]

rad cap

You need a new rad cap.
you may as well change the thermostat as well while you're at it .

I got a new rad cap about 2 months ago thanks Bushwhacker..

[Hars]

I have a 2.4 turbo 1990 G reg surf and I am experiencing some heating problems which are that when I go
for a longish drive the water goes to expansion water bottle and fills it up, if I then put back the water from the expansion
tank into main rad filler then there seems to be the right amount that i started with...for some reason it doesn't suck it up from the expansion tank
I have replaced the hose in expansion tank and it still does it, I have had the head tested for head gasket leak but was told it was ok
I also had the radiator check cleaned and tested this is ok too..am I missing something can anyone shed some light on what this problem might be and can I fix it?

thanks Shiny

I had exactly the same problem. The engine was idling during a hot summer afternoon with the air con on and it started to push out the water. I tried everything as suggested by the others. It doesn’t help. I solved the problem by moving the rad cap from the engine to the radiator (opposite to hose inlet). There is sufficient space if you use a short neck. The problem then completely disappeared. All I can think off is that the coolant additive I used generated a gas when getting hot. This was probably happening in the turbo (watercooled) The gas then created excessive pressure which pushes the water out. With the cap on the radiator, the gas accumulates under the cap and gets pushed out and the water stays behind. To confirm the gas pressure issue, listen carefully for escaping gas when opening the cap when the engine is cold. I also experienced that the gassing problem became less after running the coolant additive for about 3 months.
Also, if you want to remove the thermostat, you should block the bypass passage by plugging the small hole in the thermostat housing (the one covered by the small end of the thermostat.)