Overheating on track only

[shimmy]

Originally Posted by thegingerninja

Sometimes when the internal coolant system reaches 7 or 8 years old there can be a thin layer of corrosion across the entire internal surface area. If the water temp reaches boiling point you can get "kettling" (small gas bubbles) forming on this line layer of corrosion. Obviously the air bubbles act as an insulator and the temp will increase if you don't drop the engine load.

I think there are some products you can run through the coolant system to remove the layer, and then refill using an additive which combats the kettling. I had a problem like this on a race car and I tried a product called water wetter - I wasn't convinced it would work, but I saw a drop in coolant temps afterwards, probably about 10 degrees.

I have spoken with some other csl owners who have experienced what you describe shimmy, particularly climbing the hill at the ring. We ruled out a failing viscous fan because of the sustained high speed would create plenty of air flow. The other possibilities were: radiator had lost it's heat capacity due to ageing, water pump lost efficiency or engine running lean (due to fuel supply not meeting demand at full throttle and high revs).

Only way to find out for sure is to rule them out one at a time.

great post, thanks

my oil and water coolant system is new as is engine. water rad i have not renewed yet but have cleaned and straightened fins.

water pump is new as is sensors and stats as well as wetter used.

def not fan as you say

my thoughts now are 100 cell cat affecting ecu at full throttle or fuel system running it just lean at full throttle

i have trief another fuel pump (no change) and now have just changed fuel regulator and filter. regulator does change fueling at full throttle so maybe that it, well soon see