Rebuild????

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
I have right at 200,000 on my LMM. When is it a good time for a rebuild? OR, what’s a good mileage for a rebuild. I took the EGR and DPF off around 3,500 miles and done a few things along the way. SuperChips tuned, Injectors, Cold air and a stage three turbo, I gutted the CAT Converter so I’m straight piped but incredibly not loud unless I get on it hard. It does whistle now and that don’t bother me but I really don’t want to burn it up either.

Any help would be grateful.
 

2004LB7

Well-known member
Dec 15, 2010
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Norcal
Consider it around 500k if it shows signs of needing one. Compression check and oil pressure can get a rough idea of the health of the engine. You might be due for a CP3 if it shows signs of being weak but these engines will run a long time if not abused
 
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BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
CP3? I don’t know all the tech talk y’all use on here. The oil pressure has always concerned me. When cold it is up but after warming up it has always dropped lower than what I considered to be okay but was told on here that it was fine. What’s the low limit considered to be?
 

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
I need to update my profile here. It’s bee quite awhile since posting and I’ve done quite a bit of work on this truck. I bought it new in 09 and I have had a couple issues but overall it has been a great truck.
 

darkness

Well-known member
Jul 15, 2009
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CP3? I don’t know all the tech talk y’all use on here. The oil pressure has always concerned me. When cold it is up but after warming up it has always dropped lower than what I considered to be okay but was told on here that it was fine. What’s the low limit considered to be?
Cp3 is the high pressure fuel pump. Seems like the Lbz/lmm run lower oil pressures. My dads Lbz runs low. Low to a point that my ‘04 with compound turbos climbing a hill low.
 

Dozerboy

Well-known member
Jun 23, 2009
4,795
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TX of course
It more then just the oil pressure that tells you when it's time to do a rebuild. But if you hitting 10psi on a hot idle it's time to start looking it over. In which I would start out by adding a mechanical gauge to see if the truck is lying to you about the oil psi.
 

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
Cp3 is the high pressure fuel pump. Seems like the Lbz/lmm run lower oil pressures. My dads Lbz runs low. Low to a point that my ‘04 with compound turbos climbing a hill low.
Which pump is best bang for buck? It seems y’all give pretty good advice so I’ll take any advice pretty highly.
 

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
It more then just the oil pressure that tells you when it's time to do a rebuild. But if you hitting 10psi on a hot idle it's time to start looking it over. In which I would start out by adding a mechanical gauge to see if the truck is lying to you about the oil psi.
I run a three gauge Pillar set. Boost, Exhaust temp and trans temp. I think I will change the trans to oil pressure. I also have some tuner questions. Can you answer them or recommend someone here that wouldn’t mind talking to an old guy?
 

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
It more then just the oil pressure that tells you when it's time to do a rebuild. But if you hitting 10psi on a hot idle it's time to start looking it over. In which I would start out by adding a mechanical gauge to see if the truck is lying to you about the oil psi.
Where is the best port on the LMM to put that oil line?
 

ikeG

Oughta Know Better
Apr 19, 2011
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Where is the best port on the LMM to put that oil line?
There are plugs in the block in the oil galley. Your factory oil pressure sender is in the next to rearmost port on the drivers side. (Disregard any non hex plugs/fittings you see on this engine in the pic). You can plumb a gauge into any of the ports.
5b0a26021193499c13d399e85a5b652b.jpg


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BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
There are plugs in the block in the oil galley. Your factory oil pressure sender is in the next to rearmost port on the drivers side. (Disregard any non hex plugs/fittings you see on this engine in the pic). You can plumb a gauge into any of the ports.
5b0a26021193499c13d399e85a5b652b.jpg


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Wow! Now that’s what I call a response! Pic with circles. I could not have asked for a better response. You guys are rock solid. Just know this. I’m gonna be askin a lot more questions so I sure hope y’all are ready!!!!
 

darkness

Well-known member
Jul 15, 2009
1,218
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How much does it run? Where does it install at? my brother put a lift pump in his 13 gmc and it makes way to much noise for my taste. Is this pump loud too?
Yeah the cp3 mounts in the valley. you can check the vendors for prices on cp3’s. Just curious which lift pump (which supplies low pressure fuel to the cp3) your brother got that’s that noisy?
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
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As others have said the CP3 mounts on top of the engine underneath the thermostat bridge/housing.

As for lift pumps, FASS tends to be noisier than AirDog. The new 5G AirDog line has been pretty awesome.
 

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
Yeah the cp3 mounts in the valley. you can check the vendors for prices on cp3’s. Just curious which lift pump (which supplies low pressure fuel to the cp3) your brother got that’s that noisy?
I will shoot him a message and ask which one he got. I really don’t have and fuel issues tho. When I hit the throttle the truck is gone like a rocket. But I nervous when I see that mileage getting up there around 200,000.
 

BigTex1968

LMM's are the best.
Jun 12, 2013
22
0
1
Corsicana, Texas
As others have said the CP3 mounts on top of the engine underneath the thermostat bridge/housing.

As for lift pumps, FASS tends to be noisier than AirDog. The new 5G AirDog line has been pretty awesome.
He just told me he has a FASS. I know I don’t want that for sure but I was told I didn’t have to worry about it with my 09 LMM
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
3,895
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Neenah, Wisconsin
A lift pump is never a bad idea but at your mileage it is certainly possible to have injector or CP3 issues where either could be returning too much fuel.
 

Steve9

New member
Apr 30, 2023
22
1
3
Florida
I'm the same, hot oil idle reads about 29. Cold motor runs 50/60
Bought my '08 new in '09 235k miles
Banks six-shooter, speedloader 4" exhaust which does not much with all the epa crap still in place
Still have the egr, dfp, cat. Thinking about doing some work onto it. egr cao-off
dpf delete
cat/muffler terminal