(solved Maybe :)) Boiled The Coolant At Sandown And Engine Oil Hit 120 Degrees

[some_cs_student]

Hi,

I did the high-performance driving day at Sandown with the driver dynamics group, most of the day I was pushing it pretty hard but would do 2 hot laps and then a couple of slow laps to cool it down.

I had an instructor drive my car, Chris, he was great but we went around for 4 laps, since he was driving I didn't notice the gauges in the A-pillar.

The oil gauge had the warning light on and had hit 120degrees and the water temperature was 115 degrees.

We warmed down the car by idling it, then shut it off about 2 minutes later. The coolant was boiling in the 1st overflow tank after 5mins later, so I drove it around at about 50km/h to try and get some air in there to cool it down, the oil dropped briefly to 110 degrees but then went up to 120 degrees and water went to 130 degrees.

Anyway, I took it back and parked it, about 20minutes later the water temperature dropped back down to 70degrees or so, engine was still about 100 degrees.

All the coolant (or a huge amount of it) had been boiled out on the track, we had to top it up with water, and after that it was ok again.

I run a Greddy/Trust radiator (a thick aluminum radiator), it also has a small Apexi overflow bottle, and then the normal R33 GTR overflow bottle on the LHS. Note: all done by Japanese owner.

There is no oil cooler...

Oh, and with the radiator cap off, and the engine running, it pushes water back out of the radiator....is that normal?

Does this sound like there is something wrong? And where do I start looking?

The car drove home without any problems, the only recent change is a PowerFC and a tune by Ben from Racepace. Oh, and it was a 35 degree day.

Engine oil is (German, really American) Castrol 5w40.

Regards,

Gareth

P.S. thanks to the SAU guys for helping me out with this on the day.

[some_cs_student]

Think we might have found it, the fan does not use much force when spinning.

Ie. if we hold the fan when we turn the car on, ok.

If we hold it, run it for 5-6mins and the temperature in the water reaches 90degrees and oil 70 degrees, still nearly no resistance, the fan is not trying to spin.

We suspect the viscous coupling of the fan, just need to find another one and hopefully the problem will be solved

R31 coupling's will fit (what a surprise), BUT I had to buy an holden fan to go with it....my R33 GTR fan did not fit on the new viscous coupling. However the coupling itself did not fit see:

http://www.skylinesaustralia.com/forums/fo...-f-t210569.html

Or does an R31 clutch fan fit R33 GTR for updates on this.