Truck bought for parts, got it running, but…

[mccullek]

Not sure if true, but from my research you risk oil leaks by using synthetic oil in the HMMWV. As for the blow back, these units have often been sitting for years. Once they run a bit and the piston rings reseat, any blowback might clear up or at least improve. I would run it some before being concerned about the blow back. Give the rings time to do their thing again.

 

[T9000]

Not sure if true, but from my research you risk oil leaks by using synthetic oil in the HMMWV. As for the blow back, these units have often been sitting for years. Once they run a bit and the piston rings reseat, any blowback might clear up or at least improve. I would run it some before being concerned about the blow back. Give the rings time to do their thing again.

I did hear about the synthetic potential risk for leaks and I also did a lot of research because I wanted to use the best technology.
I ended up using synthetic on another REV HMMWV that had last oil change around 2013 (based on the oil filter date and mileage) so it sat for a while and didn’t have any leaks, the engine runs and sounds very buttery and maybe it would have sounded the same with dino oil also
In this case the leaks were already present at the valve cover and at the turbo before the oil change, and this truck seems to have been operated until recently as the a the change date for oil filter and air filter is 2020,
Yes, I will drive it for a while before worrying about the blow-by and I appreciate the feedback.

EDIT: typos

 

[T9000]

So I ran the truck today to test the valve cover leaks, four are fixed, there is one left, toughest one behind the alternator, working on it.

I went just up and down the street and when going up hill or accelerating a little, the oil comes flowing, not leaking, from the bottom of the turbo, It goes on the transmission left side and then on the exhaust, so I could tell from the smell.

The rate of flow is like a sink in the lowest setting when it goes from dripping to continuous flow, to try and quantify it somewhat.

This is not something new, that side of the transmission was gunked up in old oil residue and so was that spot on the exhaust, which I just cleaned, so it has been going on from before my time.

The truck was last serviced in 2020 based on oil filter and air filter dates, if they are to be trusted.

Clearly the snowman needs to be replaced, but so much oil coming out, what would cause it?

EDIT: I actually couldn’t see exactly where it was coming from exactly, from tracing it back, is looks like it’s the turbo base, unless there is some other source in that area?

 

[Mogman]

I did hear about the synthetic potential risk for leaks and I also did a lot of research because I wanted to use the best technology.
I ended up using synthetic on another REV HMMWV that had last oil change around 2013 (based on the oil filter date and mileage) so it sat for a while and didn’t have any leaks, the engine runs and sounds very buttery and maybe it would have sounded the same with dino oil also
In this case the leaks were already present at the valve cover and at the turbo before the oil change, and this truck seems to have been operated until recently as the a the change date for oil filter and air filter is 2020,
Yes, I will drive it for a while before worrying about the blow-by and I appreciate the feedback.

EDIT: typos

Synthetic motor oil is just a waste of money in a HMMWV, the beauty of synthetic oil is extended oil changes, well that is out the window with the Detroit, they are "dirty" engines and contaminate the oil so you cannot extend the oil change interval. again just a waste of money.

 

[T9000]

Synthetic motor oil is just a waste of money in a HMMWV, the beauty of synthetic oil is extended oil changes, well that is out the window with the Detroit, they are "dirty" engines and contaminate the oil so you cannot extend the oil change interval. again just a waste of money.

Got it! How about for the geared hubs, geared fan, differentials and transmission?

 

[Mullaney]

Got it! How about for the geared hubs, geared fan, differentials and transmission?

.
IMO, regular old sulpher based gear oil for manual gearboxes and transfer cases and front and rear axles works just fine. You won't do anything but spend money you don't need to spend going synthetic in those. First time you drive through water, you need to drain and change...

 

[Mogman]

Got it! How about for the geared hubs, geared fan, differentials and transmission?

I am not a big fan of DEX VI, I use DEX III in my transmissions and steering. I change the gear hub and diff oil every year so I can see any indication of trouble on the magnetic plugs so I just use a good GL-5 gear lube.
The exception is the 6L80 in the Detroit, the builder requires a full synthetic for warranty purposes and only recommends a change interval of 100K

 

[T9000]

I am about to open the Turbo to change the snowman and the other seal, anything else I should be on the lookout for? I will also do a cartridge leak test. Is that much oil coming out from the Turbo base and indication of some bigger issues than just seals?

 

[Mogman]

I am about to open the Turbo to change the snowman and the other seal, anything else I should be on the lookout for? I will also do a cartridge leak test. Is that much oil coming out from the Turbo base and indication of some bigger issues than just seals?

That is the only place oil can get out of the turbo, can you explain the "cartridge leak test"?
Also have you made sure the turbo bolts are tight?

 

[T9000]

That is the only place oil can get out of the turbo, can you explain the "cartridge leak test"?
Also have you made sure the turbo bolts are tight?

The way I understood it, is pouring water in the turbo input and watch if it comes out thru the oil feeds, and it shouldn’t,

 

[T9000]

Also have you made sure the turbo bolts are tight?

Actually now that you mention it, I am not sure if I did the bottom screws, for sure I did the 6 or so at the top and I ordered new turbo bolts because I felt they were a little rounded…I really was looking for a reason to open the turbo, but I agree that need to double-check the tightening first, no need to create extra work if not needed, even if I like it

 

[Mogman]

The way I understood it, is pouring water in the turbo input and watch if it comes out thru the oil feeds, and it shouldn’t,

Do you have a link to that test, I don't think that is a valid test.

 

[T9000]

Here, it's from another thread:

Turbo Intake Manifold Leak - Causes?

I see a lot of the turbo trucks with oil leaks where the turbo connects to the intake manifold. I'm not a diesel engine or turbo guru by any definition, but this seems to be way more common on these trucks than I would have guessed. What causes it? Is it indicative of a more serious problem...

www.steelsoldiers.com

EDIT: I meant to reply to the post above

 

[T9000]

Do you have a link to that test, I don't think that is a valid test.

Here, it's from another thread:

Turbo Intake Manifold Leak - Causes?

 

[Mogman]

There is very little in the way of a seal there, I would expect any GM turbo with any time on it to leak like that, oil in the intake is NORMAL, it comes from the crankcase vent system not the turbo, but by all means replace the cartridge, the Chicom ones are plentiful and cheap, under $200. EACH time you have to replace it.
BTW do not over torque the turbo mounting bolts, about 20ftlb max

 

[T9000]

There is very little in the way of a seal there, I would expect any GM turbo with any time on it to leak like that, oil in the intake is NORMAL, it comes from the crankcase vent system not the turbo, but by all means replace the cartridge, the Chicom ones are plentiful and cheap, under $200. EACH time you have to replace it.
BTW do not over torque the turbo mounting bolts, about 20ftlb max

Copy that! Will do!

 

[T9000]

Also have you made sure the turbo bolts are tight?

I just checked the bolts at the turbo base and they are at least 20ftlb, they won’t move any further even if I push it a little over. There are only two bolts at the turbo base, one on each side, correct? (11508475 in the TM)

 

[Mogman]

I just checked the bolts at the turbo base and they are at least 20ftlb, they won’t move any further even if I push it a little over. There are only two bolts at the turbo base, one on each side, correct? (11508475 in the TM)

Yes. it will be interesting to see how they messed up the seal when they installed the turbo

 

[T9000]

Just a quick update, I fixed the last valve cover leak, behind the alternator, what a pain, but it’s done and so far there are no more leaks.
Now moving to the turbo…we’ll find out how screwed up could it be

 

[T9000]

From lessons learned on first truck, I replaced the fuel lines with new ones that are slightly longer, makes it a lot easier to replace the fuel filter and air out the system from a relaxed sitting position, I suspect others have done something similar after the first fuel filter change:



EDIT: And the beer doesn’t even have a chance to warm up while on task