Oil in Coolant

[estoniaboy]

Hey,
I got LB7 Duramax that has oil in the coolant, but not coolant in oil. Engine oil is bark/black as it can be while the coolant system is nasty mix of oil and coolant. Has anyone ran into same problem as I am having? What could be the problem?
On top of the oil in the coolant there is significant pressure in the coolant system, the cap wants to fly off the overflow tank when loosened, shortly after engine crank. The engine its self runs great, no odd noises or anything.
I personally think it is the head-gasket, but I am also thinking perhaps it could be my oil cooler or..?? Any help/advice/thoughts would be greatly appreciated.
Thank you.

 

[03BlkMax]

Sounds like the head gaskets are blown

Galaxy S3

 

[darkone98]

x2 for head gaskets.

 

[estoniaboy]

Can you have head gasket(s) blown and not have coolant mix with oil but have oil mix with coolant?

 

[dirty_max]

sounds more like a bad oil cooler to me

 

[03BlkMax]

sounds more like a bad oil cooler to me

A oil cooler isnt going to pressurize the overflow tank and try to blow the cap off. Its getting compression in the cooling system.

Galaxy S3

 

[jkholder09]

what about trans oil and radiator intermix, dmax cooling systems sometimes have some pressure.
block tester available to the original poster?

 

[estoniaboy]

what about trans oil and radiator intermix, dmax cooling systems sometimes have some pressure.
block tester available to the original poster?

What exactly is a block tester?

 

[dirty_max]

A oil cooler isnt going to pressurize the overflow tank and try to blow the cap off. Its getting compression in the cooling system.

Galaxy S3

im not trying to start and argument but yes it can. if you have oil in your coolant then there is an increased volume of liquid in the tank. how high does oil pressure go? long story short, an overful overflow tank will push coolant/be overpressurized. this is coming from just my general knowledge of the diesel engines that i work on everyday, not specifically the dmax. also, im wondering how a popped headgasket can put oil in the coolant? ive seen some pretty nasty coolant from combustion gas being in it.

 

[03BlkMax]

im not trying to start and argument but yes it can. if you have oil in your coolant then there is an increased volume of liquid in the tank. how high does oil pressure go? long story short, an overful overflow tank will push coolant/be overpressurized. this is coming from just my general knowledge of the diesel engines that i work on everyday, not specifically the dmax. also, im wondering how a popped headgasket can put oil in the coolant? ive seen some pretty nasty coolant from combustion gas being in it.

Well, good luck with your theory. Lol. Guess youve never had a dmax blow a headgasket before. Guess we'll see what the op finds.

Galaxy S3

 

[dirty_max]

no I haven't, but I have had a few hundred semis with blown hgs, and bad oil coolers so its not really a theory anymore, its pretty much been proven. there must be something super special about the dmax and how it puts oil into the coolant when they pop :roflmao: it does sound like he had bad hgs, but I still don't understand how it gets oil in the coolant from a blown hg. it just doesn't make sense to me yet and I would like you explain how combustion gas going into the coolant leads to oil going into the coolant. I can see coolant going into the oil with a bad hg, but not the other way around

 

[catman3126]

Id be looking at the trans cooler. Or is the coolant black like it for sure engine oil.

 

[03BlkMax]

no I haven't, but I have had a few hundred semis with blown hgs, and bad oil coolers so its not really a theory anymore, its pretty much been proven. there must be something super special about the dmax and how it puts oil into the coolant when they pop :roflmao: it does sound like he had bad hgs, but I still don't understand how it gets oil in the coolant from a blown hg. it just doesn't make sense to me yet and I would like you explain how combustion gas going into the coolant leads to oil going into the coolant. I can see coolant going into the oil with a bad hg, but not the other way around

Since you seem soo well versed on this engine. Let me ask you this. Is 15psi greater than 40+psi? Lol

Galaxy S3

 

[dirty_max]

im not saying I am very well versed on the dmax, and no its not. please tell me more

 

[dirty_max]

what about trans oil and radiator intermix, dmax cooling systems sometimes have some pressure.
block tester available to the original poster?

no way dude, there is no possible way that it is anything but hgs dude :roflmao:

 

[estoniaboy]

Then maybe I have both the head gasket and oil cooler bad?
Has anyone had a blow gasket where oil got mixed into coolant but not the other way around?

 

[prodiesel804]

that is the only way i have seen the fluids mix with a blown head gasket.
seen this happen 20+ times.

 

[jkholder09]

What exactly is a block tester?

Just google it
They look for co and co2 combustion gas in cooling system

 

[1972oldbluespanksmy dmax]

chocolate milkshake lb7

Iam having a simular problem. 2003 dmax Still trying to figure out the cause of all this milkshake. Engine oil is clean and full with no sign of moisture. Allison oil is 1 quart low. Pulled oil cooler out and no signs of any leakage. Gonna have to replace bdcause I split ghe housing from the he cooler. Getting a pressure checker today to re fill the sludgy mess with water. No excessive pressure coming out coolant tank. Any more ides? I do see ghat the tranny
cooler hoses run to the radiator and then to a separate tranny
cooler up front. Are the lb7's turbos water cooled? This whipped mess is definitly chocolate.