• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

LB7 with EGR?

dieselfuelonly

dieselfuelonly

Member
Messages
134
Reaction score
25
Location
Florence, AZ
I just bought a 2004 GMC Sierra with the Duramax. The VIN has a "1" in the 8th digit position so this should mean the engine is an LB7. Interestingly this truck has EGR which I had no idea or expected to see it under the hood on the engine. I bought the truck from New York...so was California the only state that required egr on the LB7 engines? From what I read up the LLY has egr, but I'm dumbfounded this truck has egr and for a minute I swore it was an LLY by looking at the plastic air intake plumbing design and the way it looks under the hood! Wonder if it's ever had an engine swap done...? Doesn't look like it and still looks as factory as can be. Thanks for any clarification.
 
Many of the'04s had California style emissions nationwide. Brother in law has one that was originally ordered by a Northern Illinois dealer. IIRC they are almost exactly like the LLYS. Ferman may know a bit more about them and the mid year'04 transition
 
As said above, MANY 04's got the CALI or north east emissions package from the factory. It entailed an EGR valve, different glow plug controller, different intake heater relay, cylinder heads that flow roughly 30CFM less air, and the turbo uses a different downpipe bolt pattern. If the injectors are under the valve covers, it's an LB7. If the injector plugs are visible outside the valve covers, it's an LLY+.
 
Thanks for the information and I was dreading this being the case with the truck. The VIN states it's an LB7 and yes the injectors are under the valve covers. Bummer about the 30 CFM less air flow and it's probably due to the fact that exhaust gas is rerouting to the intake manifold. Will the truck still have the normal LB7 IHI turbo or will it possibly be something more similar to what the LLY ran? Truck has 284k miles and seller stated it needs injectors. The truck smokes white at idle and billows white while driving down the road. I do have a "check engine" light on and pulled the code tonight. It's a P0380 that looks to be related to the glow plug system. Could this code be solely the reason causing the white smoke? Probably not...still will needs injectors I bet.
 
Fed 9 (emissions lb7) are known for glow issues and lb7 are known for injector issues, I'd bet the issues you have found are exactly what they are.
 
P0380 with a CALI emissions is almost always a bad glow plug. And from the sounds you need inejctors. It uses an IHI turbo nothing like the LLY used(LLY used a GARRET VGT), but it is different than the federal turbo as GM decided to use a different bolt pattern for the downpipe on the CALI emissions trukcs.
 
THEFERMANATOR said:
P0380 with a CALI emissions is almost always a bad glow plug. And from the sounds you need inejctors. It uses an IHI turbo nothing like the LLY used(LLY used a GARRET VGT), but it is different than the federal turbo as GM decided to use a different bolt pattern for the downpipe on the CALI emissions trukcs.
Click to expand...
Sorry I might have gotten the emission code wrong.
 
10-4 on the glow plug issue. Shouldn't be too hard to find the bad glow plug with some testing. And by different bolt pattern on the downpipe do you actually mean the "cobra head" that bolts up to the exhaust side of the turbo? Where the exhaust pipe attaches it shouldn't be any different than a regular engine correct? Looking to put an MBRP 5" exhaust on it is my reason for asking...oh and is it worth deleting the EGR? All that stuff is going to have to be removed to remove the right side valve cover when I do the fuel injectors. Thanks for the great help and knowledgeable answers so far...
 
I wouldn't delete the EGR, but I would put a blocker plate in it. If you change your downpipe when you do the exhaust, you will have to specify you have the CALI engine as they do make a different downpipe for them. If you go with a regular exhaust that connects at the stock downpipe, then no changes are needed. If you do delete the EGR or block it, you will either need a retune, or install a finger stick to fool the ECM into thinking the EGR is still working. As to the glow plug issue, finding the bad one isn't that hard. You have 2 plugs at the glow plug controller(rear drivers side valve cover) with 4 wires in them. Unplug them, and take a test light, connect the ground wire of the test light to the positive side of the battery, and then touch the probe end to each wire in the 2 plugs. A good glow plug will light up the test light, the bad one(s) will not light it up.
 
Whether you get a finger stick or not depends on what you are going to run for a tune. If you're going EFI no FS is needed. I have one with Predator tune and a blocked EGR. No troubles with that setup but if I was to start over I would go EFI because there are better tune options.
 
Looks like deleting EGR is going to be an involved project if I want to do it the way I'd like to or technically the "right way" in deleting all the EGR related components. On the list I would have the right side up pipe, EGR valve, EGR cooler, vacuum pump, intake connection, and even the fuel filter housing is much different with all the extra sensors. I may just leave it on. Bought a 5" exhaust for it and it will attach to the stock downpipe coming off the turbo. Are the injectors the same for the LB7 between no EGR/EGR equipped?
 
injectors are the same. i wouldnt fully delete it, just put a blocker plate in it, and a custom tune to shut it off.
 
You must log in or register to reply here.
Back
Top