7.3 IDI cylinder/oil problem

[85Bullnose]

Bought a 7.3 that had, measuring the circumference, about 8 inches of flywheel teeth sheared off, as well as most of the starter drive teeth, which told me that something had the engine virtually locked. Considered cavitation, rod/main bearings, etc. but went ahead and took it, just for accessories and spare parts. So, attempted to rotate engine, and it would only turn about 150 degrees and then stop dead. Decided to remove glow plugs, and after removing just 4 glow plugs, #7, #8, #6 and #2. Some oil came out of #8, but a geyser of oil, that would have made Ol' Faithful proud, shot up out of #2 about 3' high. Now....hold those thoughts....the reason that #2 had so much oil, was because when I first unwrapped this engine, there was oil standing in the intake, about 1/4" to 3/8" deep. This was with the engine sitting reasonably level, from side to side. Afterwards, when I let the engine hoist down, the engine gently rolled to the side, thereby putting #2 cylinder at the lowest point of all the others. So quite naturally, the bulk of the oil would have went to it. So....herein lies the dilemma, obviously since oil is incompressible, this massive amount of oil could not have been caused by blowby. Also possible, is that someone had poured this oil in the intake, in order to free up what they thought, was a frozen piston(s). There is no way to get an accurate reading through a compression test, as it would indicate a false positive, because of oil sealing the rings. I should add that the engine can now be rotated a full 360 degrees with no binding, etc. My only solution is to remove heads, clean oil out of cylinders and reassemble with new head gaskets and retorque head bolts. But I need this compression figure to see what kind of shape it's in. Does anyone have a solution, for removing this oil in cylinders, without a tear down? As always, I apologize for the lengthy story, but I am a firm believer that, "invariably, the devil is always in the details". Thanks in advance to all who reply.

 

[Thewespaul]

This will make your day, got an easy trick for you. But first like you said the oil isn’t from blow by, likely the engine was upside down at some point, and oil drained into the intake from the crankcase depression valve. I don’t think there’s anything wrong with the engine.

Get some denatured alcohol or e85, just needs to have a high alcohol content. Get a funnel and pour about a pint into each cylinder and rotate the engine around by hand then with the starter of course with the injectors and glow plugs removed, then blow compressed air into the glow plug hole until you get nothing coming out the injector hole. Let it sit for a few hours to evaporate, then blow some more air in to confirm it’s bone dry. Then run your compression test

 

[85Bullnose]

Thanks Thewespaul! Oh yeah, at the risk of my being labelled a slacker, you are talking my language! Lol! Ordinarily, yes, I would assume the engine had been turned upside down as well, but in this particular case, I pulled the engine myself. So, unfortunately, we have to strike that explanation off the list. That having been said, while I realize the CDR can contribute greatly to oil in the intake, either the engine would have burned the additional oil or if that excessive, the engine would have just stopped. Times like this, it's very important, to be able to discuss these problems, with someone like you, who has knowledge and experience, especially when it's specific to what you're working on. I'm gambling that maybe, just maybe, this engine has some life left in it. So, I feel a compression check will tell me what I need to know. Your thoughts on that would be greatly appreciated. Looking forward to your additional input. Thanks, again.

 

[85Bullnose]

Just to add, on my way to get a gallon of denatured alcohol and flush cylinders, per your method.

 

[Thewespaul]

Well that rules out the engine flipping over as long as the truck wasn’t wrecked, it will be interesting to see what the compression numbers look like, was the oil overfilled maybe? Guess there could be a chance someone poured some oil down the intake like you said, glad I could be a help!

 

[YJMike92]

What kind of compression numbers would be acceptable on one of these motors?

 

[Thewespaul]

I think 250 psi is minimum and all must be within 20% variance to be acceptable according to international

 

[YJMike92]

I think 250 psi is minimum and all must be within 20% variance to be acceptable according to international

Thanks. I will be checking the compression on my parts donor truck soon.

 

[icanfixall]

Welcome to the forum. My guess is someone poured oil into the intake.Might have been a joke on someone but... No fluid will compress. This might be a reason for the flywheel missing teeth and ruined starter gear. Any chance this truck you pulled the engine from was under water??? That sure would cause oil to get on top of the intake because oil floats on water. It fills the oil pan forcing the oil up top of the engine. Owner may have known this and drained the water. then tried to start the engine. With these damaged parts you may have some broken pistons or bent rods too.

 

[Macrobb]

Welcome to the forum. My guess is someone poured oil into the intake.Might have been a joke on someone but... No fluid will compress. This might be a reason for the flywheel missing teeth and ruined starter gear.

So, I've gotten at least one engine full of oil(I think it was from how the engine was leaning for a while). Starter would /not/ grind - it would just engage and then stop. The starter could be damaged from holding the key down in this state for too long, but I doubt the teeth would wear out.

I also have one truck that had a damaged section of teeth. Not entirely sure what caused it, but the engine was freely spinning. It would crank most of a rev, then stop at the bad spot.
Between getting it and replacing the ring gear 50 miles later, the bad spot grew quite a bit - from all the bar-it-over, crank, starter spins freely, bar-it-over crank etc.
(Once I replaced the ring gear, never had a problem again).

 

[85Bullnose]

Thanks for the input, guys. Just to bring everyone up to speed, supposedly, according to the guy I bought the engine from, this truck had been used to pull a horse trailer. The truck was EXTREMELY clean. Personally, I would never have parted it out. Even the paint was like new. In fact, he kept the seat, because it was in such immaculate condition. The more I think about the condition overall, even though he said it had 330,000 miles on it, I've seen/bought enough trucks in the better part of my 63 years, to know that with that many miles, at the very least, there will be a lot of telltale hints, that indicate high mileage. So, no, the truck was intact, only one small dent in the whole body, interior super clean, bed like new and NO damage on the tailgate, so I'm thinking he meant 130,000. Personally, I think it may have had a leaking head gasket, set up and then was "froze up" from the coolant. Apparently they poured some oil in the intake, to free it up. Must have worked, because it will turn freely now. Had some other projects to wrap up, so, hoping to flush the cylinders, per Thewespaul's suggestion/solution and then run a compression check. While it's out, I will replace replace the head gaskets and I can see the valve cover gaskets have been leaking, so get them too. I will post compression numbers in a few days, and hopefully will have a better idea of the condition of the engine. Once again, thanks to all who have responded.

 

[Alwaysreadyrob]

Would the pink slip tell you the mileage at sale ?

 

[85Bullnose]

Alwaysreadyrob, I did not get to see the title, as I suppose it wasn't really a issue. I bought the engine, radiator, crossmember mounts, and a few other odds and ends. I have known this guy, for several years, bought a few other parts from him, and while we are not friends, per se, more like acquaintances, I trust him. He is not, however, familiar with diesels and doesn't like them. As I had mentioned in an earlier post, personally, I would have never parted this truck out. Just too nice and clean, but, that's basically what he does. So, I went ahead and bought the engine, just for parts. I figured if it ran out good, that would be great. If not, I had a fair number of spare parts, as the engine had all the accessories on it. Down in these parts, the IDI's are almost extinct. So many went to the scrap yards, back when the price went up. Sad, so sad. I haul a load of scrap every so often, as it accumulates, but I seriously hate to go to the scrap yard as I know I'm going to be sick at everything that's in the pile. And worse yet, they won't sell it back for ANY price. Crazy.

 

[Alwaysreadyrob]

Im in CA and you just dont find these trucks around, not even in the junk yards.
But hey, for every one thatos on the road ... thats just
“ one less prius “ lol