Outer Limits 4x4 Board

hi guys got a surf that is overheating and like to know what you guys think it may be

things we have done is

new head
water pump
thermastat
new raditator
and the fan is working

the cooling system has been pressure tested and it is holding.....while the motor is running it is building pressure and pumping it in to the over flow

head gasget maybe? could be pressurizing the cooling system.

Wonderboy wrote:head gasget maybe? could be pressurizing the cooling system.

the head gasget was done

Was the head checked for cracks? Surf engines never blow head gaskets they just crack heads

Can I suggest

http://www.toyotasurf.asn.au/forum/

Not much these guys don't know about the woes of owning a Surf...

ok we put a new thermastat in and rad cap has stop it overheating while driveing but now if it idles to long the temp will go up but if you rev it up the temp will go down

If you look at the size of the radiator it is smaller than a standed diesel radiator so would suggest to upgrade it

where did you get your radiator from?

I got a cheapy off ebay and it was shocking - ended up paying to get a recore job done on my radiator instead, cost a few hundred extra, but now i never have to look at my temp guage again.

The ebay job weight difference compared to the recore was huge, toyota rads are about 15 fins per inch, the ebay job was only 11 - despite an advertised 14. plus 2 less tubes vertically as well.

The recore i got has been perfect.

thehanko wrote:where did you get your radiator from?

I got a cheapy off ebay and it was shocking - ended up paying to get a recore job done on my radiator instead, cost a few hundred extra, but now i never have to look at my temp guage again.

The ebay job weight difference compared to the recore was huge, toyota rads are about 15 fins per inch, the ebay job was only 11 - despite an advertised 14. plus 2 less tubes vertically as well.

The recore i got has been perfect.

we got the rad recore stock rad just recore

Nat84 wrote: and the fan is working

Just because it is spinning, doesn't mean it's doing it's job. It's a viscous fan, with engine at operating temp and TURNED OFF the fan should be fairly stiff to spin by hand. If its spinning freely it needs to be replaced or have the hub pulled apart and more viscous fluid added (search).

This would probably explain the fact that it will only overheat at idle and why when you rev it (forcing the fan to speed up) it cools down.

RAY185 wrote:

Nat84 wrote: and the fan is working

Just because it is spinning, doesn't mean it's doing it's job. It's a viscous fan, with engine at operating temp and TURNED OFF the fan should be fairly stiff to spin by hand. If its spinning freely it needs to be replaced or have the hub pulled apart and more viscous fluid added (search).

This would probably explain the fact that it will only overheat at idle and why when you rev it (forcing the fan to speed up) it cools down.

like i said the fan is working as we pulled the hub apart and added more viscous fluid

Fair enough, can't see any other reason the temp would drop when you rev it other than water pump blades heavily corroded but you've allready replaced this too. Only other thing is some sort of blockage somewhere.