Coolant combustion

[mylamb]

The dealer said they believe it is the oil cooler. Would a failing oil cooler allow oil to mix in with coolant, while not permitting coolant to get into the oil?? Engine is still coolant free. Weird. And where is the coolant disappearing to? Just evaporating? This is a dealership and they seem to be clueless in regards to diagnosing these engines. The "BOOM" was a hose giving way - only $30.

[Steve Tinker]

I would imagine that the oil pressure would be higher than the coolant pressure.
There is probably an internal leak in the heat exchanger which, when hot, allows the oil to impregnate the coolant. But as the engine stops & cools, there is still pressure in the cooling system (but not in the lubrication system) which forces a small amount of coolant into the oil. This coolant would then evaporate when the oil is again up to temperature.
At least that's my theory.....
I would be interesting to know if Porsches "never needs replacement" coolant has anything to do with these failures.
Looks like Brad & JFP's diagnosis were correct - again!!

[mylamb]

They replaced the oil cooler & flushed the system with detergent. We will continue to monitor it for the next few months. They said if that isn't it, then the last option they can think of is a tear down. I will probably have to get a second opinion before I go that route. The BOOM that I heard was a hose - $30. Surprisingly, with all the problems I've had with Warranty America, they almost matched the dealership on the labor rate (paid $149 of $158/hr) and matched the number of hours. That's something they never used to do - capped out at $100/hr in the past. All I had to pay for was the tow, deductible, and a couple of gallons of coolant during the flush. I'll post feedback whether the problems persists or goes away.

[gav2009]

hi everyone!
haveing just got a boxster s 2000 2 weeks ago i have noticed oil in water too!!!
please let me know if its the heat exchanger and i hope its not the heads! and i dont have a waranty so i might have to get my hands dirty...is it hard PLEASE HELP

[Steve Tinker]

Get yourself the Bentleys repair manual - it gives the explanation on how to replace the heat exchanger. Make sure you get the S exchanger as it is larger than the standard Boxster unit.
You will definately have to replace the coolant and preferably flush the system of old oil too. If this is beyond your mechanical skills, there are a few indipendants in the North of England that can help, Hartechs / Autofarm have a good reputation - or log onto BoXa.net for closer help.