Overheating on track only

[shimmy]

Originally Posted by lawsy

Have you fitted your pump/reg yet?

You got text BTW

Yep fitted and ready to try it

[Funkster]

As been said already, oil up to 125 but water temp rock solid in the middle.

That's on my old engine and the new one !

With standard cats but SS middle and back.

[glendog74]

Originally Posted by CraigMillwardCroft

I was at Circuit de Bretange last year temp around 28 degrees, and oil temp went to 125 but water no problem, does this help my oil temp when on track rises to 125 all tracks.

Originally Posted by Funkster

As been said already, oil up to 125 but water temp rock solid in the middle.

That's on my old engine and the new one !

With standard cats but SS middle and back.

As above for me Shim:

Oil temps rise on mine during high ambient temps (to approx 125) but I have yet to see my water temps rise...

SS headers/200 cell OEM cats/SS centre/SS back box

[3wheels3]

Have voted but to confirm in txt...no mods & no over heating. Water temp rock solid. Always make sure oil temp is around road temp returning to pits.

[alexk]

shimmy

My problem was faulty thermostat and fan coupling.

thank you please

[maxmeerkat]

If your water temps are rising, have you considered the bmw motorsport thermostat ? Will be fitting mine soon.

[shimmy]

Originally Posted by alexk

shimmy

My problem was faulty thermostat and fan coupling.

thank you please

Alex, remind me when your overheating happened (did it meet the criteria I pointed out above)

Originally Posted by maxmeerkat

If your water temps are rising, have you considered the bmw motorsport thermostat ? Will be fitting mine soon.

Put in new stat then Motorsport stat. Does not make any difference to this as it is at hot conditions when any stat will be fully open

[maxmeerkat]

I guess next step is a race bonnet from Geoff Steele

[shimmy]

Originally Posted by maxmeerkat

I guess next step is a race bonnet from Geoff Steele

maybe but not to cure this, it is something much more fundamental than that

[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.