hey everyone,
I have an automatic 240GL 1989. Recently I checked the oil and found pink oil emulsion in the top of the radiator reservoir. It has the consistency and colour of auto gearbox oil when you rub it on your fingers to remove the water.

There is no evidence of water in the engine oil and the gearbox dipstick shows clean transmission fluid. I also drained the sump of the gearbox a bit....clean fluid as well.

Consequently, I changed the radiator fluid and waited to see what happened. 1 month later there is again a pink emulsion in the reservoir. The gearbox oil appears to have risen over time (ie it is way overfull at cold temp) so I again drained the sump to see if there was any water sitting in the bottom but the transmission fluid is still clear. I am of the impression that water is heavier than transmission fluid.....is this correct?

To add to the problem- my overdrive wont engage and i am driving on the freeway in 3rd gear. Changed the old faulty overdirve relay 2.5 years ago. When the car is cold, the relay works, the arrow on the dash alternates on and off, but no engagement of overdirve. After about 25 mins driving, the car changes into 4th gear and the box will change in and out of overdrive by pressing the button after this. It seems that the overdrive will engage when the car is fully warm. Could this be related to water in the gearbox? I am assuming if the connections on the relay were cracked the cracks would open up and i would lose overdrive as the relay warmed up and anyway the relay seems to work ok, it seems the prob is closer to the box.

Having replaced my radiator 1 year ago, the transmission oil breach comes as a surprise and thus i was wondering. Can the auto fluid cooler communicate with the radiator cooler via any possible means?

I know this is long, but it has got me stumped with the little knowledge that I have of these cars. If anybody is willing to take 5 mins to offer me some advice I would be very appreciative

many thanks
Michael T