Just gonna say im an ex mechanic and have raced all my life but am in too **** a mood to even think atm as this has just tipped me over the edge

overheated to 115c in servo last nite... lost 2ltrs coolant and steam everywhere... babied it home and it was fine when driving due to airflow

fan fuse was blown... used the heater fuse and got the fans working.

when driving... sits on its normal 82-84c temps

when stationary it climbs to 92c which is when the fans kick in and they cool it back down... rinse and repeat if im stationary long enough

flushed system 3x, new coolant and replaced thermostat tonite... still doing the same thing

ideas? i didnt think it would be waterpump as it runs fine when driving... its just stationary

no leaks, no airflow restriction - car has been faultless for 55,000kms of track abuse, daily driving and 3-4 hills runs a week... car now has 103,000kms

BHR ignition, cobb ap, bhr flywheel, straight through exhaust from headers back, knightsports 2nd oil cooler are the engine mods

 

If your fan fuse blew, it blew for a reason. Think about it.

 

fan motors are cactus?

but that doesnt explain why it gets up to 92c now when stationary... it never goes over 84c (fans come on at 92c)

 

It's doesn't, you likely have more than one problem. Look at your coolant system as a whole, it only works properly if everything is working together correctly.

 

Are both fans working?

 

Havent checked both fans however my understanding was they both kick in at once... its not staged... unless im incorrect and only have 1 fan kicking in at 92deg and the other would normally come on quietly at 84deg?

 

If you lost a fan, one would suck air in, and that air, while stationary, can go back out the other side of the radiator and get sucked through a gain. There are several suggestions in the $100 thread in my signature that might help. They involve a fans on low modification as well as a way to seal around the radiator to keep the hot air on the hot side.

 

There are 3 fan speeds... there is a different combo of speeds and fans to get there.

Check that the relays are all working...and the fans......

 

would bet its a fan issue. You can also make sure your core is nice and clean.

 

Also keep in mind that if you change out any of the heater hoses and coolant hoses that have restrictors in them, you need to remove the restrictors and reuse them. Without them the car will over heat.

I'm not sure why exactly but we ran into this issue on a fresh rebuild, it started to get hot on the first start so we shut it down. We checked everything and it made no sense (all new components) and then I remembered about the restrictors and asked the owner if he removed them from the stock lines and he said he did not. We reinstalled the restrictors and all has been good since.