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r/Duramax•
VisionOverload

LLY Head Gaskets - things to replace/check while apart?

So about 2 years ago I made the poor decision to buy a fairly modded LLY. 05 with 165k miles 5 position tuner 6" lift and 37" tires. At the time the dealership service department lied and said the head gaskets were fine. They replaced the water pump after they got it on trade. At the time I couldn't find a local diesel shop that remembered seeing it to give me an opinion on it. Recently it started pushing coolant out the overflow. Did thermostats and burped the air out well and was good for a while. Then recently it dumped the entire reservoir over a short distance on a rural highway. Took it straight to the best diesel mechanic in the area and low and behold, they recognized the truck. They had diagnosed it with head gasket issues with the previous owner and he traded it in instead of fixing. $5000 should get the head gaskets sorted as long as heads aren't badly warped. While the cab is off, what other things should I have done or check? I'll save on some labor costs if I do some extras while they are already tore into it. Going to have the injectors tested while they are out. Going to have them check pump rub issue on the transfer case while it's in the shop. I believe the turbo mouthpiece was upgraded already but I'll have to double check. Looks like a I have a leak on the intercooler so I should look into that as well. Transmission feels really solid but not opposed to doing a little something while it is apart. Any other things to hit now to prevent having to tear into it again in the near future? It really wasn't treated great by previous owners but I'm attached and want to keep it for at least another 150k miles which will be quite a while for me. In retrospect, I certainly should have kept looking for an LBZ truck but they are pretty hard to find in my area.

Edit: Missed a few things. Turbo will be checked as part of the head gasket job I was told by the shop. Truck has had an EGR delete and full 4" exhaust. S&B intake that's an old model, have the new one ready to install as they will discount the new version if you have an older version.

Posted Mar 9, 2020, 9:21 PM UTC · edited

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pudge1824george•

I would for sure check and more than likely replace all the soft fuel lines in the cab at the fuel filter head and the CP3 should be a total of five lines I believe

They did the water pump recently but check the small little bypass rubber hoses in front of the motor as well as the upper one that feeds the turbo replace more than likely as well

I don’t know where you were sending the injectors off to be checked but you should also send off the fuel rails and hard fuel lines to be cleaned since they will be off

Try to have the CP3 checked since it will be easily accessible

Having the turbo also checked for play would be fairly easy with everything else coming off

Having a boost leak could also mean a hurt turbo

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VisionOverloadOP•

Yeah I forgot clearancing the turbo was a part of the head gasket job. Thankfully I've put only a couple thousand miles on it since buying it. I'll look into the list above. Thank you for the input!

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CountryBoydCustoms•

It doesnt sound like its modded to much but if you wanted more power it would be easy to get the turbo modded you can mod the stock turbo on the lly for some decent power as well you can get a good aftermarket exhaust on 4" or 5" and get the egr deleted properly while the cab is off and should the the fuel rail plug upgrades as well. all good and much easier to access with the cab off

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VisionOverloadOP•

It has had an EGR delete and the entirety of the exhaust has been upgraded to 4". I rushed my typing this up on the phone. I'll edit in a couple things into the main post also.

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creditedpawn•

Glow plugs, especially if you actually going to need them.

Fuel pick up and return lines, they are steel rubber combo

When you floor it what is the max rpm the engine will do?

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VisionOverloadOP•

It seemed to have plenty of get up and go but I'll probably check the fuel pressure regulator while it's apart. Glow plugs were great even on some Sub zero days this winter so they are probably fine.

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