7.3 idi coolant in oil

[robert snodgrass]

I have a 91 ford f 250 with a 7.3 with 68000 on it and I bought it 8 years ago and right after I bought it it started mixing oil with coolant wasn’t to worried bout it figured it was an oil cooler so after bout 2 weeks I changed oil whichlooked like it had been awile after that worst fears started I started gettingcoolant in my oil so I parked it which brings me to today 8 years later I now have the money and means to work on it so I took out oil cooler out re sealed itpressure tested it dumped oil changed and flushed coolant crossed fingers andstarted truck sucker started right up ran just as fantastic as before after 8years of sitting ran it on off fore rest of day ranging between 10 minuets to hrs checking oil in between all was perfect till the next weekend went to start truckbut before I started it checked the oil and the dreaded water in oil again I need to know what u guys think no coolant in exhaust doesn’t run bad no excess pressure in radiator no symptoms at all other then the water in oil and it only leaks into the oil when not running and that is where I am lost I did hear agurgling noise today when I was adding water to it to try and pinpoint leakdon’t know to much history on truck other then the guy I got it from didn’treally know much bout them and couldn’t afford to do annything to it and I don’t believe he was running sca he was second owner before that it was afarm truck and was bought new I am leaning towards head gaskets and orwater pump which has rtv all the way around it sorry bout long post ideaswelcome

 

[IDIBRONCO]

Hopefully, for you, I'm wrong, but I'm thinking that it has a pinhole in a cylinder from cavitation. I don't think that there's any way for a bad water pump to let coolant get in the oil. Another thing, it probably wasn't a good thing to let it sit for 8 years with coolant in the oil. It could have rusted things such as the crankshaft. Of course that's depending on how much coolant was actually in the oil. A little bit can look like a lot after it's mixed up. Did any coolant drain out of the oil seperately? When it was running before, was there any white smoke in the exhaust indicating burning coolant? A pin hole that's towards the bottom of the cylinder will allow that cylinder to burn coolant since there's not much compression until the piston moves upward in it's stroke. The higher the piston, the higher the compression.

 

[robert snodgrass]

Oil was drained and filled before it was parked and yes water came our separately it was drained again before start up no water that time but cooling system was empty till it was filled fore start up no white smoke no nothing no smell doesn’t run funny nothing tons of power was not thinking water pump specifically but more so the plate between it and the timing gears

 

[lotzagoodstuff]

I'm sure you looked at it closely, and it sounds like you pressure tested it, but any chance the oil cooler has a corroded pin hole in it? Again, I know you did rebuild it and I know you pressure tested it, just trying to make sure you aren't overlooking the body of the oil cooler leaking.

If it was me, I'd pull all the glow plugs, get an adapter to pressurize the cylinders via the glow plug holes and do a true leakdown test on each cylinder and see if you get any bubbling in your coolant system. If that didn't pan out, with the glow plugs removed I'd try pressurizing the coolant system with a radiator cap adapter and seeing if/when any coolant appears anywhere interesting.

After that, I'd think about raising the white flag and giving in to the block worm/cavitation cause and tear it down.

Good luck, sounds like a nice low mileage rig that you can hopefully bring back for a second life.

 

[robert snodgrass]

The leak down test and compression test is what is next ordered compression gauge wating fore it to get hear glow plug removal is slow going as their are original and almost 30 years old I do have spare oil cooler making rig to bench test it before I assemble it to the ends I have a 9 second video of truck running trying to figure out how to post it now really hoping it’s not a block issue but machine shop quoted me 1000 bucks to sleev all 8 to stock and cavitation will be history at that point prepared fore worst but hoping fore best

 

[lotzagoodstuff]

glow plug removal is slow going as their are original and almost 30 years old

Soak them with PBlaster and/or Kroil. There's also a newer product that Loctite makes called Freeze and Release that works very well.

 

[IDIBRONCO]

While you're doing the leak down test, if your cooling system is low, you can put your ear over the radiator fill and listen for air/bubbles.

 

[robert snodgrass]

xc_hide_links_from_guests_guests_error_hide_media

This is the video of it running after 8 years of sitting before coolant in oil was discovered again still runs that way if I wer to start it


I was gonna loosen rockers and do the compressed air into cylinders fore 3 minuets like suggested on hear will fill cooling system with water again before I do

 

[genscripter]

I don't think that there's any way for a bad water pump to let coolant get in the oil.

Actually, there is a very LIKELY cause for coolant to get into the oil:

xc_hide_links_from_guests_guests_error_hide_media

Also, if the front plate seal went bad, that would lead to coolant in the oil.



Probably the least likely place for coolant to be in the oil would be the oil cooler or oil cooler headers. Oil pressure almost always exceeds coolant pressure, so in places of high oil pressure (near coolant passages), the oil pressure will leach into the coolant circuits. That would be the oil galleys, oil cooler, oil cooler headers, and so on.

If I were you, I would forget about the compression test and oil cooler fixes, and focus on your water pump and front plate gaskets. If after you change those and you have coolant in your oil, then you probably have a head or block problem. Maybe a new HG could resolve the issue. After that, you probably have a cracked block or cavitation issue.

 

[IDIBRONCO]

If this was to cause, you would also have a small amount of oil seeping out around the bolts. Both of these conditions would be caused by bad gaskets, not by the water pump itself.

 

[robert snodgrass]

Ok guys thanks fore input will start doing some reasearch and let u know

 

[robert snodgrass]

So I finally had time to do compression test on engine did it cold and hot results are as follows cyl #1=310 cyl#2=320 cyl#3=350 cyl#4=320 cyl#5=330 cyl#6=315 cyl#7=310 and cyl#8=330 I did put a lil oil in cyl#7 and re tested it and got 350 out of it their was not a significant difference between cold and hot so at this point I’m trying to decide if I just pull engine and rebuild it or do the head gasket and heads and call it a day if I go rebuild rout I will have all 8 cylinders sleeved so I never have to worry bout cavitation but i was hoping to postpone engine rebuild fore a few years I have not preformed the shop air in cylinders yet but did do radiator leak test and it goes from 16 psi to 0 in less then 5 minutes your thoughts on topic are welcomed

 

[lotzagoodstuff]

I have not preformed the shop air in cylinders yet but did do radiator leak test and it goes from 16 psi to 0 in less then 5 minutes your thoughts on topic are welcomed

Spend a little more time and effort and find out where your coolant pressure is going. Don't worry about sleeving or rebuilding until you've ruled out everything else that's easy and not so invasive. Get a stethoscope, some of that fancy leak finding dye, and anything else you can think of and concretely find the source of your oil in water.

I would also highly recommend and a friend with a different set of eyes/ears. Yesterday I got a package with two brand new potato peelers from Amazon. I asked my wife why, and she told me she spent 20 minutes looking for a peeler to clean some carrots, gave up and ordered two new ones. I opened one drawer moved one potholder, and there was the old one. In her defense: we just moved and everything is in a new place, but this was really in the drawer she admittingly looked in first and longest (go figure: it's where it should have been ). Sometimes you just need another perspective to shed some light on things.

Good luck, glad to see you are still bringing new life to this old rig.

 

[Macrobb]

I'd say you have three likely failure points:
1. The front cover / water pump gasket. This is the simplest to replace and cheapest.
2. The Intake manifold gasket. Earlier 7.3 IDI heads have coolant ports facing the intake(valley pan) gasket, which are simply dead-headed there by the gasket. Later model IDIs have plugs pressed into the heads here, so it won't leak even without the valley pan gasket. Not sure on what exact year/serial that they switched to plugging those holes.
3. Head gasket(weep from pressurized coolant hole to oil drain hole). Also a totally valid cause, especially if you see any coolant weepage around where the heads meet the block(usually rear outboard corners).

 

[Conky]

This is the video of it running after 8 years of sitting before coolant in oil was discovered again still runs that way if I wer to start it


I was gonna loosen rockers and do the compressed air into cylinders fore 3 minuets like suggested on hear will fill cooling system with water again before I do

sounds nice... too bad you must SELL IT