1994 F-350 7.3L IDI factory turbo. 199,000mi

Gets oil in the antifreeze (about an eighth inch - maybe less - at the top every 100-200 miles). It's not a lot. There was oil in the overflow when I bought the truck. I've since cleaned it out and haven't seen it get oil in it - just empty itself.

I have yet to see an absolutely obvious sign of antifreeze in the oil. I have seen a very small build-up of 'milkshake' on the oil cap, and only after lots of driving. The oil level seems to stay constant. When I bought the truck, it was slightly low on oil, topped it off, and have driven it about 350 miles with no discernible change to the level.

I've read threads with similar problems, and have changed the oil cooler o-rings and gaskets. I couldn't afford to have it pressure tested. I changed the coolant when I did this, and tried to clean oil out of the radiator... was not able to get everything. I expected to see some more oil show up as it washed out of the system - but how long should this happen for? (its been 100 miles or so now) I did not change the oil - out of $$$ at the moment to do so.

Truck has no blow-by, and no white smoke out the tailpipe. I also see no bubbles out of the radiator while running. Hence why I went the oil cooler route.

Unfortunately, like I mentioned, the truck is still getting oil in the antifreeze, and is using small amounts of antifreeze - the overflow bottle continues to empty slowly.

What do you guys think is the problem? Should I drive it longer and see if I keep getting oil in the antifreeze - and if so how long?

Thanks in advance.

 

As far still seeing it show up in the rad that could be residue from inside the block washing out yet. Loseing coolant could be any number of different things includeing leaking out some where. I had a volvo wagon a while back that had a split heater hose that only leaked when the engine was under torque and twitsed to the side . Sitting idleing it didn't leak. took me a week of searching to find that one and 3 hrs in freezing cold to fix lol.

 

Until you do a good cleaning of the cooling system you really have no clue if that is old oil or new oil from an oring screwup.

There are some good commercial cleaners.....

Restore........ Cummins Filtration

Some members just use Dawn.......

 

How might I go about cleaning the system out? (with Dawn?)

So far as loosing antifreeze goes and a leak... I haven't seen any 'leaks' per say, but the hoses do seem to be... umm... bleeding? Like they end up wet on the outside - not dripping, just a light coating of... water, I think. Not sure whats going on there? Thats ALL the hoses related to the coolant too. I'll look more closely for signs of a leak tomorrow. My last truck (89 IDI) did not do that, nor did the 6.9 before that. Not sure if it's related the oil contamination.

I think I might pull the oil drain plug real quick too (like for a second), and see what comes out.