Hi,
>
> I was hopeful that someone might be able to give me a different insight
> into a problem that occurs with my dads celica. The car has an issue where
> that around every 150000kms it cracks the head into either the number 2 or
> 3 exhaust port. the engine is a 3S-GE with TVIS. The only mods are a cold
> air intake to feed the factory air box and a set of tri-Y long primary
> exhaust headers. The car has done it to 3 heads so far and always the same
> problem. The engine runs fine when the head cracks and still produces full
> power it just pumps the radiator into the exhaust with a cloud of steam.
> It has also has had the engine changed the last time it happened to a jap
> spec motor. The car has had the water pump, the thermostat and the
> radiator replaced that the car never has any heating problems. It usually
> has the oil changed every 5000kms with the longest it's been being
> 7000kms. The car does a lot of highway driving occasionally towing a
> lightly loaded trailer. On average it does about 800kms per week. About
> the only thing that has happened to the car other than normal wear and
> tear is that the heat from the exhaust warped the blades on one of the > radiator fans.
> The only thing I can think of is that the head gasket it not allowing
> correct water flow to the head and causing a hot spot which causes the
> cracking, But I'm not convinced this is the cause and the head gaskets
> used are identical in water flow holes to the factory Toyota one. >
> If anyone has any ideas as to what could be the cause I'd be grateful to
> fix this problem as my dad would like to keep using the car for work for
> as long as possible.
>
> Nick
Hey, Nick. Retired VIP's suggestion sounds good. I'd return everything to stock and see what happens.
Stupid question: did you make sure the block and head mating surfaces aren't warped (I'd be thinking more like block...maybe a high spot somewhere)
Nice to 'see' you again!