Mystery Motor!

MilkTruck · December 5, 2006

Ok. I bought my 2007 2500hd classic in october. My VIN comes back with a U in the 8th spot, and my glove box RPO has LQ4. Pretty straight forward so far. But I have been comparing these 2

LQ4--- http://media.gm.com/us/powertrain/en/produ...SLV-C%20LoR.jpg

LY6--- http://media.gm.com/us/powertrain/en/produ...20SBN%20LoR.jpg

pictures for about a month now, and have come to 3 possible conclusions.

1. I have an LQ4 motor with LY6 INJECTORS, water pump, and power steering pump.

2. I have an LY6 motor with an LQ4 engine cover, and incorrect VIN and RPO codes.

3. The GM official media site has incorrectly labled/posted these pictures of the respective motors.

PLEASE anyone chime in here with any input. I will STRESS that I am NOT blind, and have very carefully compared these pictures with my engine. My engine has the crome power steering filler neck thing, the SHORTER water pump neck (The upper outlet of the water pump) and the injectors on my engine have the same 2 bolts on the left hand side holding them to the fuel rail.

My next step is to take it BACK to the dealer to have them settle it once and for all, but I value everyone's input here as well.

Particular thanx goes to MS3DALE for his help in this matter

MilkTruck · December 5, 2006

Any Thoughts?

Wingnut · December 5, 2006

I'd put a paycheck on reason #3.

MilkTruck · December 5, 2006

Here is another site with an LY6 pictured. It is even the same pic used on the first site. That is the motor in my truck, I know it!

http://www.gminsidenews.com/index.php?page=Engine_Guide

Why don't my VIN and RPO codes match!? will this lead to warranty/service problems?

MS3DALE · December 5, 2006

MilkTruck,

You do not have the LY6 6-liter motor,You have the LQ4 6-liter.

You can't go by the pictures GM supplies,They are not always exactly the same as pictured,Believe me I see it everyday here at the dealership where things are different from whats pictured in parts catalogs and brochures.

One example,The bright "non-painted" power steering pump you mentioned,GM started using those in the '05 model year so yours should be a bright "non-painted" one.

On the injectors I have no idea,I can't see them on either of those pictures,All I can see is the fuel rail and coil packs.

MilkTruck · December 5, 2006

MilkTruck,
You do not have the LY6 6-liter motor,You have the LQ4 6-liter.

You can't go by the pictures GM supplies,They are not always exactly the same as pictured,Believe me I see it everyday here at the dealership where things are different from whats pictured in parts catalogs and brochures.

One example,The bright "non-painted" power steering pump you mentioned,GM started using those in the '05 model year so yours should be a bright "non-painted" one.

On the injectors I have no idea,I can't see them on either of those pictures,All I can see is the fuel rail and coil packs.

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the coil packs then, is what I was referring to. Im used to seeing injectors in that location (on my Buick GN)

I am willing to accept the power steering filler being different. What else might I look for to be sure? anyone know a surefire way? Truck is in the driveway right now....

MS3DALE · December 6, 2006

Well I can tell you that on the coil packs GM uses a couple different ones,We have to go by either the casting number on the coil pack or in some cases actually compare them side by side to tell which ones an engine has.

So we have to actually stock a few different part number coil packs,We can't just stock one part number for all of them because theres more than one.

I have also seen different coil packs on the same year and size engines,In other words your '07 2500HD LQ4 6-liter might have different coil packs than another '07 2500HD LQ4 6-liter,It all depends who supplied the engine plant with coil packs when the engine was built.This is especially true on the '99-'01 GEN III truck engines but I've seen it on newer ones to.

Oh,And to make it even more confusing......Theres different length spark plug wires too!....Depending on which coil packs you have.

Being a parts guy sometimes is no fun,Its gets stressful at times!!

Trust me though,If you would bring your truck into our dealership and it needed parts for the engine,I would order them for the "LQ4" 6-liter and I'm 100%,bet my paycheck on it (Although it ain't much of a paycheck!) that they would be the correct parts needed.

BlackSilver · December 8, 2006

Oh,And to make it even more confusing......Theres different length spark plug wires too!....

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Now I'm really confused. What are "coil packs" and "spark plug wires" and how come Chev left them offa my motor? Can I get them added back on under warranty?