M923A2 leaking coolant into engine!?!?

[BrokenArrowLodge]

Good day guys, I've got a 923A2 with the 8.3L Cummins. I am loosing coolant into the engine I think, the oil looks good but getting some steam/moisture and sludge out of the crank case vent. I will send an oil sample in to confirm.....

Question is, is this common with this engine, and is there any other places other than head gasket that it can leak?

I searched the forum for other similar posts, but if there out there please send me a link.

Thanks guys.

 

[simp5782]

Good day guys, I've got a 923A2 with the 8.3L Cummins. I am loosing coolant into the engine I think, the oil looks good but getting some steam/moisture and sludge out of the crank case vent. I will send an oil sample in to confirm.....

Question is, is this common with this engine, and is there any other places other than head gasket that it can leak?

I searched the forum for other similar posts, but if there out there please send me a link.

Thanks guys.

any oil in the coolant?

If there Is then suspect a bad oil cooler. Pressure for oil is higher for that leakage.

 

[BrokenArrowLodge]

any oil in the coolant?

If there Is then suspect a bad oil cooler. Pressure for oil is higher for that leakage.

No I dont think so, it didn't look like it, and I am not loosing any oil. In 700 miles I have went through 5 gallons of coolant. ( and about 60 idling hours)

 

[simp5782]

No I dont think so, it didn't look like it, and I am not loosing any oil. In 700 miles I have went through 5 gallons of coolant. ( and about 60 idling hours)

But your oil isn't grey?

 

[BrokenArrowLodge]

But your oil isn't grey?

Nope, not at all..... but lots of steam/water coming from Crank case vent. (-30 here as well). And sludge, like a puddle in the morning.....

 

[simp5782]

Nope, not at all..... but lots of steam/water coming from Crank case vent. (-30 here as well). And sludge, like a puddle in the morning.....

Wet stacking can cause moisture from lots of idling. The engine doesn't get to temp and doesn't allow the moisture that the engine oil has in it to burn off like it normally would.

You may pressure test the system and check for leaks. Or even isolate the aftercooler and pressure test it.

 

[BrokenArrowLodge]

Wet stacking can cause moisture from lots of idling. The engine doesn't get to temp and doesn't allow the moisture that the engine oil has in it to burn off like it normally would.

You may pressure test the system and check for leaks. Or even isolate the aftercooler and pressure test it.

Ok, that makes sence. And especially when its -30 to -40, its running cold for sure. We are operating on snow, so super easy to see a leak. And 5 gallons is hard to miss!!!

 

[simp5782]

Ok, that makes sence. And especially when its -30 to -40, its running cold for sure. We are operating on snow, so super easy to see a leak. And 5 gallons is hard to miss!!!

Not always. If it's above the exhaust it could burn off before you see it when it hits the manifold.

Aftercooler would be leaking and burning off in the motor compression.

 

[WillWagner]

Take the oil filler cap off at the valve cover and have a look, do this carefully so if there are drops of water under the cap, you can test them. Mayo on the bottom side means water/coolant in the oil. I ASSUME you are running antifreeze, so, if you have the mayo under the cap, and have carefully removed the cap to save the drops of liquid, give one of the drops a taste. No taste other than a bit oily, rain, condensation, contamination from outside of the engine. Sweet, antifreeze UNLESS you are using the newer type of ELC antifreeze, then it will be very bitter AND this could be the cause of your issue. Your vintage of engine was not designed for ELCs, it will eat the rubber parts in the cooling system.

Another thing to check that is common and fairly easy is the compressor. Don't remember if there is a dryer, but drain the wet tank. If antifreeze is there, the issue is at the compressor

 

[INFChief]

Good day guys, I've got a 923A2 with the 8.3L Cummins. I am loosing coolant into the engine I think, the oil looks good but getting some steam/moisture and sludge out of the crank case vent. I will send an oil sample in to confirm.....

Question is, is this common with this engine, and is there any other places other than head gasket that it can leak?

I searched the forum for other similar posts, but if there out there please send me a link.

Thanks guys.

Does this has a transmission oil cooler & is that oil contaminated?

 

[BrokenArrowLodge]

Take the oil filler cap off at the valve cover and have a look, do this carefully so if there are drops of water under the cap, you can test them. Mayo on the bottom side means water/coolant in the oil. I ASSUME you are running antifreeze, so, if you have the mayo under the cap, and have carefully removed the cap to save the drops of liquid, give one of the drops a taste. No taste other than a bit oily, rain, condensation, contamination from outside of the engine. Sweet, antifreeze UNLESS you are using the newer type of ELC antifreeze, then it will be very bitter AND this could be the cause of your issue. Your vintage of engine was not designed for ELCs, it will eat the rubber parts in the cooling system.

Another thing to check that is common and fairly easy is the compressor. Don't remember if there is a dryer, but drain the wet tank. If antifreeze is there, the issue is at the compressor

Awesome!! Thank you for the info. Never thought of the compressor!

 

[WillWagner]

Check to see what it is first or you will start tearing into things that don't need to be messed with. Do the taste test or use a refractometer

 

[Valor]

Take the oil filler cap off at the valve cover and have a look, do this carefully so if there are drops of water under the cap, you can test them. Mayo on the bottom side means water/coolant in the oil. I ASSUME you are running antifreeze, so, if you have the mayo under the cap, and have carefully removed the cap to save the drops of liquid, give one of the drops a taste. No taste other than a bit oily, rain, condensation, contamination from outside of the engine. Sweet, antifreeze UNLESS you are using the newer type of ELC antifreeze, then it will be very bitter AND this could be the cause of your issue. Your vintage of engine was not designed for ELCs, it will eat the rubber parts in the cooling system.

Another thing to check that is common and fairly easy is the compressor. Don't remember if there is a dryer, but drain the wet tank. If antifreeze is there, the issue is at the compressor

What is an ELC antifreeze? Thanks.

 

[WillWagner]

What is an ELC antifreeze? Thanks.

ELC is the "new" type of antifreeze. Extended Life Coolant. I forget the whole story about it, something to do with not being sweet as to not attract animals. It is very acidic and, if used in early products, like the years of all the green things here on SS, will attack rubber components in the cooling system including any o-ring that seals coolant, any head gasket with a rubber seal around coolant passages, rubber thermostat seals, liner seals. IIRC, buna-n and nitrile rubber is affected, Viton, I believe, is safe for ELC.

Any coolant that is not green, yellow or blue is an ELC, red, orange usually indicate ELC. The two types cannot be mixed. If that is done, the fluid will turn dark and gel and start plugging things up. The blue coolant fielded by Cummins is compatible with ELCs, it will darken if mixed, but will not gel.

They say it is extended life and if the engine is deigned for that type of coolant, all is well. NOT! I have a 2006 Silverado with a D-Max in it. At around 130k, the w/p failed. I had been noticing coolant temp running lower than normal before the pump started leaking. I did the pump and stats at the same time. When I pulled the stats, the rubber seals were mostly black goo allowing coolant to bypass the stats. The truck had GM DexCool in it. It now Cummins blue stuff in it. Even though I flushed it multiple times, the coolant is darker than it starts out from the container, but has not gelled.

 

[BrokenArrowLodge]

Take the oil filler cap off at the valve cover and have a look, do this carefully so if there are drops of water under the cap, you can test them. Mayo on the bottom side means water/coolant in the oil. I ASSUME you are running antifreeze, so, if you have the mayo under the cap, and have carefully removed the cap to save the drops of liquid, give one of the drops a taste. No taste other than a bit oily, rain, condensation, contamination from outside of the engine. Sweet, antifreeze UNLESS you are using the newer type of ELC antifreeze, then it will be very bitter AND this could be the cause of your issue. Your vintage of engine was not designed for ELCs, it will eat the rubber parts in the cooling system.

Another thing to check that is common and fairly easy is the compressor. Don't remember if there is a dryer, but drain the wet tank. If antifreeze is there, the issue is at the compressor

So pulled the filler cap off the valve cover and there really was no water on it. Some sludgy looking oil, but still mostly black......

However, the water coming out of the crank case vent is definitely antifreeze!!! Taste test confirmed!!

 

[WillWagner]

OK, so now you know it is from the engine. If there is no oil in the coolant, the oil pressure is greater than coolant pressure, it will be the air compressor, aftercooler, liner, head, block or head gasket. If it were me, i'd drop the pan and pressurize it. Air compressor will be from the front gear train, that's where oil drains back. Might be easier to look at the discharge to see if coolant comes out when pumping. Between the piston and liner is one of the other places. The reason you find where it is leaking from is so you aren't guessing and throwing parts at it. If coolant comes from between the P&L at 3, you know to focus on that area. You will see leakage evidence on the aftercooler core when you remove it to pull the injectors, usually looks like bloom around a slow leaking hose clamp. Next to look at is the head. This vintage of C likes to crack between the seats and nozzle bore, use a magnifying glass and look carefully. The head gaskets should have the permaseal around the water passages, you will see the red bead broken and pushed out, but, head gasket failures USUALLY had evidence of external leaks. The show as white streaks normally ay around 2/3 cylinder and if bad enough, the streaks run off of the exhaust rear of the block. The blocks on this vintage engine were prone to cracking between the liners at 2-3, 3-4, 4-5 and 5-6. Cracks ran in line with the crank and show up at the thinnest part between cylinders. If that's the case, the only fix at the time was to re block it. No crack, that will be a good thing, is a liner. They are spun steel, mid stop and the only time I saw liners fail due to pitting was in trash trucks, water trucks and off road equipment that when coolant needed to be added, plain water was used. The liners just rust out. This usually shows up at the top of the liner between the liner and block deck and at the top of the mid stop seal area. I have seen it bad enough that the rust/cavitation took out the liner and block.

Still COULD be an oil cooler, if you pressurize it and it looks like coolant is coming out a main bearing cap, that will be the issue, but, C engines usually had oil foaming out the radiator when oil coolers failed

 

[WillWagner]

I forgot, one more place, between the block and liner, this is a midstop o-ring or heavily cavitated liner/block.

Or overheated

 

[INFChief]

Let’s recap;

Loosing coolant. 5 gallons in 700 miles. Engine oil level is not increasing. Doesn’t overheat. No visible coolant leaks; No coolant spots on the ground. Transmission oil is not contaminated. You do see what appears to be steam/moisture/sludge blow by from the crankcase breather / vent tube. You taste tested what’s coming out the vent & its coolant. No significance milky residue under the oil filler cap.

Any further troubleshooting? New discoveries?

 

[BrokenArrowLodge]

Let’s recap;

Loosing coolant. 5 gallons in 700 miles. Engine oil level is not increasing. Doesn’t overheat. No visible coolant leaks; No coolant spots on the ground. Transmission oil is not contaminated. You do see what appears to be steam/moisture/sludge blow by from the crankcase breather / vent tube. You taste tested what’s coming out the vent & its coolant. No significance milky residue under the oil filler cap.

Any further troubleshooting? New discoveries?

Nothing new yet INFchief, I new that the oil was going into the engine, was just really looking for info on typical failure points. Got some great info and idea on how to test before tearing down. I need the truck for a couple more weeks, and hopefully by that time we will be into + weather up here. I will be tearing into it in June or July. I have to leave here around the first of May to let the ice come off the lake, then fly back in to open the lodge. Will certainly document the findings and report back.

Thanks a million for the help guys....always muchly appreciated!!

 

[WillWagner]

I remembered another thing. EASY fix. If, at sometime in the life of your truck, it was filled with plain 'ol water, well that caused rust, cavitation, etc. The soft plugs can be damaged when just water is used. When you drain the water and install coolant, the damage should stop, or be slowed from progressing further. Well, if this has happened, there are a few soft/freeze plugs in the head, under the V/C that will leak, causing coolant in the oil. Most of the time when the start, they leak under pressure only but get to the point that they leak as fs as coolant can be putin. When you pressure it, remove the V/C to have a look at these. If they are the leakers, just do them all and you'll be done.

Just a thought