6v92 detroit coolant in oil?

[nodwell]

I have an old snow blower truck that has a great running 6v92t for the blower. I was hoping someone could give me some clues about the most likely places the coolant could be leaking into the oil. I don't see any oil in the radiator and I pulled the inspection covers off the air boxes in the block and don't see any evidence of coolant there. Any advice I can get is greatly appreciated. Please excuse any lack of knowledge I might have, since I am not a professional mechanic. Thanks in advance!!

 

[wornout wrench]

Check to make sure that the weep hole for the water pump is not plugged.

 

[Vetech63]

How much coolant over how much running time? Most cases are liner orings or head orings.

 

[kshansen]

Check to make sure that the weep hole for the water pump is not plugged.

Dang mud daubers can be a bitch about plugging up those hole especially on an engine that sets for long periods of time! Had a 16V-71 water pump seal that would not leak coolant under pressure but would when set over night. So if checking do it both ways.

Almost forgot to mention, INJECTOR TUBE ORINGS! Pull valve covers and look for trails coming down from under injectors.

Might also be able to see leaking from head seals if looking down the oil drain hole at lower edge of heads.

 

[nodwell]

Thanks for your responses. I don't have a very good guess as to how much, but I do know it has extremely little run time on it. I bought it a couple of years ago and it had fresh oil changes then. The only run time is an occasional start just to get the batteries charged and get some oil circulated. I wanted to use it over the last month with the heavy snows. I checked the oil and thought it looked suspicious, since it was just starting to get a milky look to it. I cracked the drain plug and got coolant running out to make sure. A heavy equipment fella I know told me to check and see if I had oil in the radiator. I think I put about 4 gallons of coolant in to get it up to where I could see it in the radiator.

 

[Birken Vogt]

You might want to get an ultraviolet setup with dye, special glasses and a special flashlight. Add some dye to the coolant, then run until it's circulated, then remove the valve covers and pressurize while shining the dye light around and down the oil drain holes.

Or you might get lucky like I did, just remove the valve covers and you happen to notice a small trail of coolant. A drop of water stands out from the oil in there by sight a little bit.

 

[nodwell]

Please correct me if I am wrong, but the repair manual I bought shows a wet sleeve on top of the air boxes and a dry sleeve below? Therefore, I'm assuming that if is liner O-rings it would leak into the air boxes and not necessarily into the oil pan? Thanks for everyone's help!!

 

[nodwell]

The engine does have a supposed history of sitting for long periods. Supposedly, a fella bought it back in the 80's and fixed it up with a new blower engine with the idea of getting a big snow removal contract. Evidently, he didn't get the contract and it just sat for many years. Another fella bought it from him and it mostly sat for a few more years. I've had it for a couple of years and ,obviously, has pretty much sat most of the time here. Like I said earlier, I'm not a professional mechanic, so I'm not really sure what I'm looking for in a water pump weep hole in a detroit, but hopefully can figure it out. Thanks again for everyone's help!! This forum is a great opportunity for me to learn from everyone!!

 

[kshansen]

Please correct me if I am wrong, but the repair manual I bought shows a wet sleeve on top of the air boxes and a dry sleeve below? Therefore, I'm assuming that if is liner O-rings it would leak into the air boxes and not necessarily into the oil pan? Thanks for everyone's help!!

Well to be honest here I have had almost no experience in the 92 series my self!

First off you are probably right that if the coolant leak was from the upper cylinder orings the coolant would go into the air box and not straight into the oil pan.

Also there are drain lines from the air box that "should" let to coolant drain out or at the least most of it before it has a chance to get to the oil pan. I say "should" because those pesky mud daubers mentioned above could have plugged up those drain pipes as the engine sat for long period of time.

And the oil rings at the bottom of the pistons "should" hold the water from getting to the oil pan, but they are not without ring gaps and not knowing how long this coolant leak has been going on there might have been time for it to drip through over time.

One more thought or two. Are you sure it is coolant in the oil and not just water from condensation over the years? Also are you sure the radiator was ever full?

 

[Former Wrench]

If you run out of suspects, sometimes oil coolers go bad. They corrode and start to leak. This is especially true if there is a history of using untreated tap water as coolant.

 

[DMiller]

The earlier 92s had air box drains back to the pan, most were bypassed back to nature as all good Driptroits were, check to make certain those tubes are not connected to the oil reservoir.

 

[nodwell]

Thanks Again for everyone's help!! I'm pretty certain that the water in the pan is not just condensation, since it was green when I loosened the drain plug. I'm pretty certain the drain to the air boxes just go to the outside, but I will double check. I don't see a weep hole in the water pump, but I do see in the manual where it shows a water seal that supposedly can be removed without taking the pump off. I can't say for certain that the radiator was full. Before I took it home I had a fella look everything over to make sure everything was up to par, so I don't recall if I checked it or not. I would think that I would have, since I'm quite a stickler for stuff like that.

 

[nodwell]

My heavy equipment friend thought that if the oil cooler was the culprit that a person should see oil in the radiator, since the oil pressure would push it out? Does this sound right?

 

[DMiller]

With the engine running usually get oil to water if a big enough leak will flow both ways. I too would fall back to w/p first, there is a intercooler in the engine valley below the blower, if the drains do go back to the block and oil pan that is another likely spot.

 

[kshansen]

I'm just assuming the water pump on a 6V92 is more or less the same as on 8V71 so I would be very sure there would be a weep hole. The thing is you may not be able to see it with pump mounted on the engine.

I dug out my 1981 92 service manual and for some reason they don't see the need to show the weep hole between the coolant and oil seals. I would be very surprised if there was none!

They do say the seal "can" be replaced without pulling the pump but it would not be my plan of attack if it was my engine.

I'm thinking this because if the coolant seal is what is leaking and the coolant is getting into the oil it has to be bypassing the oil seal so that seal maybe damaged as well.

 

[DMiller]

Could be just Maybe injector coppers, and I said Maybe. Not seen much I have only witnessed one leak coolant to the head surface but can happen.

 

[John C.]

I've seen coppers leak. Pull the valve covers and check any soft plugs or deprecians on the top of the heads. The coolant will accumulate there and engine oil will cover it up. A quick dip of your finger will displace the oil and any coolant will show up green. A leak on a copper will drain back to the pan with the oil.

 

[nodwell]

 

[nodwell]

If I would pull the water pump cover off and pull the impeller I'm assuming the weep hole would be behind the impeller???? Thanks again for all the great responses!!

 

[nodwell]