Huw Powell human747 at
Thu Aug 8 22:41:17 EDT 2002

> Hmm, I just don't buy that the water and oil temps are as independent as you're making

Why not?

> expecially considering oil temps are almost double what they should be

at 150 C, they are about 25% over a comfortable 120 C.

> and the water temp hasn't budged a bit?  You've got oil and water all moving around in the same aluminum head, water and oil temps are quite correlated, you add more cooling capacity to either oil or water, and both temps reflect the increase.  Something's not adding up here for me, I've never seen this IME.

In all my experience, it is so common as to be second nature, almost.

it's not the head that heats the oil to 150 C, it's the two *really* hot
places it goes, which are the turbo and the backs of the pistons.  Of
course the turbo is also water cooled, so it is not such a factor.
However, the oil sprayed on the pistons gets some serious exposure to
heat, and then *is not* water cooled before passing the temp sender.

BTW, when I did the WP/TB on my 90Q and ditched the aux radiator, the
two temps took on a whole different set of inter-relationships.  Not
that it mattered, everything was still happy.

Huw Powell

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