sea dog

In a truck, I know you can get to the oil drain plug and maybe see if there is some coolant there. On my pan it's on the side with a fitting for an oil change pump and can't quite get what I'm looking for far as the coolant in the oil goes. I got a good oil sample though to compare with one 3 months ago. Maybe it will tell something, or preferrably nothing. Is there anywhere else I can look for moisture/coolant that might be a sign of an internal leak?

I asked the marine mechanic up the road about any way he could routine dianose the motor. and he said I would need a bigger leak than I have to justify really starting to tear things down looking and that though it is possible, these Macks are workhorses and built real tough. I hoping if anything it's where the exhaust maniflod had been previosly welded and I can get by for 3 more weeks of fishing before I have to get it off and pressure tested.

well I dont know anything about prestone but yes it is heat exchanged cooled and turbo charged. Both add ons to marinize the motor. Is also sea water cooled after cooler , gear cooler. The heat exchanger, exhaust manifold, aftercooler, gear cooler, and fuel pump I believe are all of the marine aspects.

Losing 2 quarts of coolant in a 12 hr day. No external leaks, new heat exchanger, hoses, etc. Put dye in system, no visible leaks or out of exhaust. 14 lb system and put 17 lb or so pressure still no visible leaks. Had a crack welded in exhaust manifold 3 years ago and when we put dye in the system, it was very visible. 1.) Could a leak this small, even with dye, be steaming off or something before it gets to the exhaust? 2.) If it were a cracked head, and leaking stays the same amount, could I get by a little bit before having to deal with it, and what signs might I look for for cracked head senario? Commercial fisherman in Hatteras,NC. Not many guys around here to help with issues. I bought this motor righ tout of the box 14,000 hrs ago and has been great to me with scheduled maintenance. Some of the guys around here have over 20,000 hrs on their's. Thanks

Well the good news is the oil has cleared up with the cleaning out with detergent. I' m usually not that lucky and guess the oil has been in there for a while since the last time I had a problem with a clutch cooler. That would have also introduced oil into the coolant, correct? Anyhow, thanks again until next time and I will post some pics of the motor early next week.

I can't get to the oil cooler change out until next Tuesday. My boys are fishing the boat this while week though. Am I risking more damage by still running the boat?

Again thanks for the help. I will post some pics as soon as I can. I drive the 160 foot car ferry for the state 94 hrs a week this week and than back on the commercial boat next week. I will do the work after hours and should have the pics soon. I hope the oil cooler is the problem and not a head gasket. I will let you guys know my progress.

Yeah that's right. She turns 2335 under load and properly wheeled. Thanks for the help. How much on the Dawn dish detergent and can I run her for a 12 hour day with the Dawn in it, or just long enough to get to temp and than drain and or flush?

Yeah, its truly a workhorse motor. 5 of us have one here in Hatteras and we put them to the test. I've beeb thousands of miles and hours on the ocean and hopefully due to PM and care she has not let me down yet. I do have the overhaul and service manual. I did drain the H2o yesterday after installing the new heat exchanger and it was a milky yellow color but still felt like water instead of oil. It dyed the water in a barrell I dumped it into, not oily surface, just colored the water. could this be residual oil from in the cooling system? If it starts to clean up after dumping it a few times, can I use some detergent to run through the system to clean it all out before I charge back with coolant? If oil remains though I do have a spare cooler to try next. Sorry Im kind of ranting here but if there is oil, shouldn't I be losing it somewhere? and if it was from the motor, not the gear, wouldn't it be black instead of clean oil?

Thanks Big Dog. I'm from Jupiter, Fl. currently Hatteras,nc

Been taking care of this motor since new. I'm no mechanic but have kept it running thus far 12,500hrs. Mostly pm and marinized parts. Heat exchanger, clutch cooler, after cooler, exhaust mainfold and turbo charger. These are the $$ parts. I have a spare heat exchanger and swapped it out just because its been 5 years and I think Its been losing some coolant somewhere. Any how, when draning the coolant, the last 1/2 gallon or so was oil, or at least a very oily mixture of collant and oil. I have had a clutch cooler problem 2 years ago and replaced. Maybe some oil still residual in there.I'm quite sure I've replaced the coolant since then though. Exhaust manifold should be just air and exhaust? I just put water in Heat exchanger and have ran about 50 hrs and am going to drain it again and see if there is any oil in the new one. If there is, shouldn't I be losing oil from somewhere? dipstick or trans?

Motor new out of box in 2004. 12500 hrs today. Have manuals and think I know the motor pretty good by now. No major work done so far except for PM, coolers,turbo, and such.All the marinized parts anyway. Does anybody have a little time to talk with me about some oil in heat exchanger possible problems? Thanks.