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AQ145A Oil Cooler Question

cdykstra01

New member
Ok, this is probably a dumb question... I have an AQ145A which runs well after I did some fuel system work this summer. Part of that work was a new gas tank. While the old tank was out I thought it'd be a good time to clean the oil cooler because it was easier to get to without the gas tank in the way and it probably had never been done. I removed the cooler, took it apart and cleaned the insert IAW the manual I have, put it all back together with 4 new O-rings (three on the cooler - two bigs and a small - and one where it mounts to the engine block) and re-installed it. I also replaced all of the rubber grommets on the inlet and outlet water tubes.

So, now I have water in my oil and I'm wondering if I reassembled the oil cooler incorrectly. Also - and this is the dumb part - I'm having a hard time seeing how the oil and water in this cooler DON"T come in contact with one another. Do the large rubber O-rings form the seal that prevents the oil/water mix?

I noticed that the manual calls for that long bolt in the cooler to be torqued to a certain spec; I didn't have a torque wrench on hand so I just tightened it down snug. Could that be where my problem lies?

Also, after running the engine to running temperature and then letting it cool down, I noted that the oil level on the dipstick was not elevated as I'd expect it to be if there were a massive water or coolant influx. It was at the proper level, just with that cloudy haze. The anti-freeze level in the closed system was unchanged as well.

Finally, the mechanic at my marina suggested that the water in the oil was probably from condensation, as this engine hadn't run for nearly a year. I'm in the upper midwest so a portion of that year includes temperature fluctuations which could contribute to condensation. BTW - the marina does the maintenance on my boat so I'm pretty confident it was properly winterized, not that I haven't wondered...
 
Oil cooler...sea water runs through the tubes, oil surrounds them... normally can't mix unless there is a hole in one of the tubes. Normally, oil is @ 40 psi or higher, while sea water is actually (with cooler before the sea water pump) at a slight vacuum. Therefore any leak would normally be oil into the sea water. i.e., high pressure to low.
 
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