Whats happening to my diesel. It starts and runs great except that there is water in the oil sump and oil in the water and it happens pronto. Doesn't miss. Replaced the oil cooler (ouch) and same problem.

 

Im guessing you have a head gasket problem. On the big trucks, to know for sure. you would pull the oil pan. then pressurize the cooling system and see where the coolant is comming from. On big diesels there is always the possibility of having a pin hole in the cylinder do to electolisis. I havent heard of this being a problem in the b-cummins. My guess is head gasket, but you need to do some testing first

 

Thanks for the reply. Because the engine starts and runs good (no misses), I been scratching my head. Also it never ran hot but it is up to
300,000 miles so there may be some wear and tear on the old 1990.

 

Sounds like a head gasket to me, too.

 

I had an 93 cummins do this as well. Mine turned out to be a hair line crack in the block by the #6 cylinder. I finally found it by having the block X rayed after disassembly. Hope yours is just a head gasket though.

 

Just a question Dave, why couldn't that be a hole in the oil cooler?

 

He posted yesterday in the "Help" section saying that he had already replaced the oil cooler.

Without that info I would have suggested he check the oil cooler first.

Good eye, Sonny.

 

In post #1 he said he replaced the oil cooler. New one could be leaky, though...

 

You're getting slow in your old age, Greg...

 

looks like head gasket

 

Not so good an eye if I missed that one.

 

I think the head gasket popped like a weazel.

 

How much oil is it putting in the coolant? If its missing it sounds like a head gasket. If it runs fine and is pumping oil in the coolant check the oilcooler and gaskets for leaks. Make sure u torque the bolts to specs or u will have the same all over again. Lots of oil in the coolant usely means a bad oilcooler. Good luck

 

Hey those are great comments. I am going to re-check the torque on the oil cooler bolts. I checked the first oil cooler at slightly over 100PSI and no leaks in a tub of water. I do not like the looks of those oil cooler gaskets. I told Cummins I thought they needed a good dose of gasket sealer and they said "use them as is" and I did and the same problem. Water and oil scourge was coming out the radiator cap hole like one of those "snakes" fireworks at 4th of July. After replacing the oil cooler I have been reluctant to use a lot of water and when did fill the radiator, the oil clouded quickly and I stopped.

Before buying a new oil cooler (now made in China rather than Canada) I changed the gaskets on the 1st one and the problem changed from just oil in the water to oil in the water and water in the oil. I think your comment about the gaskets is good and I'm going to grease em up this time.

I have 3 & 4 cylinder detroit diesels in our heavy equipment and used to make and sell generators out of Lombardini diesels over in Hawaii and I kind of expect better porformance from a good engine.

 

I always use sealer on both gaskets if they do not have a steel center and a rubber type seal on them. All cummins replacement gaskets will be steel and rubber sealed on the water and oil side of the cover. After market ones will not. Good luck Make sure u flush the hole cooling system many time,s over and disconect the heater core durning the flush. An back flush and forward flush the cooling system. Take the oilcooler off so u can also get the block inside and out. Do the same with the heater core buy it self using low pressure water flow. Use diesel or a degreaser in the flush to cut the oil out. Also remove the termastat very first thing before the flush buy a new one.