Truck bought for parts, got it running, but…

[T9000]

Ok, so I began to disassemble the turbo, first I washed, cleaned, vacuumed around and behind the turbo and setup a plastic cover to catch any gunk or sand falling from above:



I removed the crossover (taped the intake openings) and it’s coated in oil:



I loosened the exhaust and the two collars that come from the two exhaust manifolds and removed the exhaust side turbo wheel cover :



The wheel rotates easily, but it has about an 1/8” side to side play, it feels like it’s a lot. Isn’t it running on some kind of bearings? If the bearings are compromised, could the exhaust gases make their way into the oil output feed and into the crankcase?

The wastegate seemed stuck, couldn’t be moved in any direction, until I removed the bolt that keeps it attached to the exhaust part, after which it can be moved with a lot of difficulty and it squeaks loudly. It stays in whichever position it’s being set, there is no spring, push or pull or any active response, is it normal?



If it’s broken, and it wasn’t opening, would that cause the type of symptoms I have?

I still have to remove the turbo and the two collars are loose but the 2 output sides seem stuck, maybe due to rust. Is there an easy does it method to release the output side or it requires a mallet?

 

[Mogman]

Once the waste gate controller is removed the waste gate should swing freely, it was closed as you can see where it was contacting the port, ether way would not cause the issues you are having.
The turbo runs on bushings there will be some play for oil clearance but 1/8" seems a little excessive.

Did you ever find a rebuild tag on that engine?
While you have the turbo off is a good time to get some clear pictures of the casting numbers off of the rear of the block to see if you have a GEP block.
Unfortunately "rebuilt" Humvee engines have a rather poor track record being built by the lowest bidder, I am sure all kinds of shenanigans go on to increase profit.

 

[T9000]

Once the waste gate controller is removed the waste gate should swing freely, it was closed as you can see where it was contacting the port, ether way would not cause the issues you are having.
The turbo runs on bushings there will be some play for oil clearance but 1/8" seems a little excessive.

Did you ever find a rebuild tag on that engine?
While you have the turbo off is a good time to get some clear pictures of the casting numbers off of the rear of the block to see if you have a GEP block.
Unfortunately "rebuilt" Humvee engines have a rather poor track record being built by the lowest bidder, I am sure all kinds of shenanigans go on to increase profit.

These are the only markings I found:

An upside-down 3 and J28 on the driver side:



A GEP part number on passenger side? But it’s not on the block itself :



Is it a GEP engine?
Could they install a GEP intake manifold but still use an older non GEP block?

Do I need to use a mallet to get the turbo output connections loose, or is there some other more “civilized” method?

 

[Mogman]

The casting numbers on the rear of the block right in front of the transmission will tell you if the block is GEP, the intake looks to have a GEP part number but in a rebuild that may not mean anything.
Once you get the turbo unbolted and the clamps out of the way put some up pressure on the turbo and tap the exhaust couplings with a rubber mallet to see if they will come loose.
There should be a tag on the engine somewhere identifying who rebuilt the engine, whomever did the work did not take much care in painting the engine as there seems to be allot of runs.
I have not dealt with any rebuilt HMMWV engines but a tag with the rebuilder and the rod/main and piston over/under size is common practice on all military engines, or at least it used to be...

 

[T9000]

The casting numbers on the rear of the block right in front of the transmission will tell you if the block is GEP, the intake looks to have a GEP part number but in a rebuild that may not mean anything.
Once you get the turbo unbolted and the clamps out of the way put some up pressure on the turbo and tap the exhaust couplings with a rubber mallet to see if they will come loose.
There should be a tag on the engine somewhere identifying who rebuilt the engine, whomever did the work did not take much care in painting the engine as there seems to be allot of runs.
I have not dealt with any rebuilt HMMWV engines but a tag with the rebuilder and the rod/main and piston over/under size is common practice on all military engines, or at least it used to be...

I will keep looking, the only other markings I can see, are the GM Melton 6.5L valve cover stickers:


But it’s nothing engine specific and like you said, on a rebuilt anyone could install those.

 

[Mogman]

It was rebuilt by Melton, unfortunately they do not have the best reputation according to some posts here on SS.

 

[T9000]

The turbo runs on bushings there will be some play for oil clearance but 1/8" seems a little excessive.

It sounds like I should replace the cartridge, correct?

 

[REF]

I would replace it with any noticeable side play.

 

[T9000]

I would replace it with any noticeable side play.

I ordered it, should arrive on Monday or Tuesday.

 

[Mogman]

I rebuilt mine with a new shaft, bushings and compressor wheel, it seemed to have an excessive amount of play until I turned it over and filled it with oil so they are going to have a noticeable amount of play, you may as well replace it, just remember all the cartridges being sold now are from China.

 

[T9000]

I rebuilt mine with a new shaft, bushings and compressor wheel, it seemed to have an excessive amount of play until I turned it over and filled it with oil so they are going to have a noticeable amount of play, you may as well replace it, just remember all the cartridges being sold now are from China.

I prefer not to buy anything from China especially for the truck, it feels like it’s such an insult, like I have a broken side mirror and only need the glass so I am looking to buy an used OEM one just to get the glass because most new mirrors are from China and some vendors advertise them as OEM. I will use the cartridge just to prove that indeed the turbo is problematic and if it turns out that’s the case I will rebuild the existing one and keep the Chinese part as backup. Where did you get the new shaft?

 

[Mogman]

I prefer not to buy anything from China especially for the truck, it feels like it’s such an insult, like I have a broken side mirror and only need the glass so I am looking to buy an used OEM one just to get the glass because most new mirrors are from China and some vendors advertise them as OEM. I will use the cartridge just to prove that indeed the turbo is problematic and if it turns out that’s the case I will rebuild the existing one and keep the Chinese part as backup. Where did you get the new shaft?

I looked around and found a few NOS parts online, I ended up using a Chicom "wicked wheel" compressor as I could not find any NOS wheels.
The turbocharger is one of the most basic mechanical devices, you will probably get good service from the ones available now and I think it would be difficult to find any US made replacement parts

 

[T9000]

I looked around and found a few NOS parts online, I ended up using a Chicom "wicked wheel" compressor as I could not find any NOS wheels.
The turbocharger is one of the most basic mechanical devices, you will probably get good service from the ones available now and I think it would be difficult to find any US made replacement parts

I see, so instead of replacing the cartridge, you only replaced the wheel with a “wicked wheel “, that particular brand or different?
I will just go with the standard cartridge for now, just to get it to a good baseline. (need to add Boost and EGT meters before making any changes)
Was able to connect with someone at Melton, very knowledgeable, ran the engine number they stamped on and found out they received it in 2012 and they did a 30 day turnaround remanufacturing on it and a 4 hours testing tun without a block change, so it should be a GEP in theory. I will keep digging, where would the original engine s/n should be (on the wall facing the transmission? Or on the side? Passenger side?) Is it a barcode, like the transmission or it is casted in the block?

 

[Mogman]

I rebuilt my cartridge with NOS shaft and bushings but could not find a NOS compressor wheel, so i installed an aftermarket wheel, it has a longer nose than a stock wheel, lots of people sell the same dang wheel, but there is one company that calls it "wicked" total hokum I believe now, I believe a stock wheel would perform just as good.
EDIT, the exhaust (turbine) wheel is permanently attached and balanced to the shaft. and if you ever want to dissemble your cartridge the nut on the compressor wheel has left hand threads.

10lb is all you ever want to run on this engine, I hot rod everything I have, wind it up till something breaks, fix it and do that again is my motto.
But when it comes to the Detroit forget it, it is a zero sum game, You don't need an EGT meter, I have one on my GEP turbo and it is really boring.
If you limit your boost to around 10lb and the motor is in good condition you will not have any problems..

 

[T9000]

Once the waste gate controller is removed the waste gate should swing freely, it was closed as you can see where it was contacting the port, ether way would not cause the issues you are having.

How could I test if the wastegate is not stuck and that in fact it's working properly?

 

[Mogman]

How could I test if the wastegate is not stuck and that in fact it's working properly?

The waste gate is super simple, it is just a spring pushing against the "valve" in the turbo, when the back pressure gets to the point it overcomes the spring pressure it bypasses the exhaust turbine, as long as the valve is not stuck in the exhaust elbow it will work.
Here is a link to modifying the waste gate so it can be adjusted

Turbo waste gate conversion to adjustable

I was asked to make this its own thread. I converted the stock waste gate controller to make it adjustable, was really easy, just grind off the crimp in the middle of the "can" until it gives up the "cover", then carefully grind the end of the rod (spring end) until the spring cap is free...

www.steelsoldiers.com

 

[T9000]

The waste gate is super simple, it is just a spring pushing against the "valve" in the turbo, when the back pressure gets to the point it overcomes the spring pressure it bypasses the exhaust turbine, as long as the valve is not stuck in the exhaust elbow it will work.
Here is a link to modifying the waste gate so it can be adjusted

Turbo waste gate conversion to adjustable

I was asked to make this its own thread. I converted the stock waste gate controller to make it adjustable, was really easy, just grind off the crimp in the middle of the "can" until it gives up the "cover", then carefully grind the end of the rod (spring end) until the spring cap is free...

www.steelsoldiers.com

Yes, I read your post before, it’s excellent, and will modify mine once I get a boost gauge as I have no idea about the spring strength and I am not there yet to just “feel it” like I can with other things. I will inject some CLP inside the wastegate for now to soften any rust and just get the engine running at its regular baseline. Once the engine looks like it’s working correctly then I will start making changes.

 

[T9000]

Here how he turbo base looks like, it’s like the seal is there but it wasn’t doing anything:





I know the turbo was tight way over 20ftlb because I when used the same wrench to unbolt it and it felt closer to 40ftlb before it released.

EDIT: There is a part number on the block that was covered be the turbo, which looks like 1255556? Is this the right GEP block?

 

[nairb]

My melton has the same number and on the date code side it has "H100". Rather than being stamped on the block it looks like they are tags that were attached:

Attach files

 

[Mogman]

That snowman looks damaged on the feed side, such a simple thing I wonder how they screwed it up, I think the numbers you are looking for are on the other side of center