2023 GM Duramax Diesel 3.0L I6 - Test Drive Impression

[Travelin Ram]

i see now. I will not be in the market for a new truck for a decade. But, that truck is a temptation. I also saw an AT4 duramax that was nice!

Better not wait too long. In ten years buying a diesel will likely be outlawed.

 

[tjfdesmo]

Just want to add that, other than being made by Bosch, the CP4 is not any version or adaptation of a CP3. They are totally different architcture and construction. Not even close.

 

[HEMIMANN]

I'd guess the diesel option won't be the high percentage engine choice by customers. At least those that don't know that GM's gassers are oil-pumpers (after 40-70k miles).

 

[18CrewDually]

Just want to add that, other than being made by Bosch, the CP4 is not any version or adaptation of a CP3. They are totally different architcture and construction. Not even close.

And to add to this, CP4.1 and CP4.2 are 2 different pump displacements. A CP4.1 is a single (1) bore & piston used on smaller engines like BMW diesels. The CP4.2 is the pump Ford continues to use and Cummins "tried out" for '19 & '20 on the 6.7 before going back to a CP3 design.

 

[Travelin Ram]

So, what HPFP is used on the GM 3.0?

 

[18CrewDually]

So, what HPFP is used on the GM 3.0?

I believe it uses a Denso pump similar to the HP3. It is a v-twin bore like the Bosch unit 4.2.
It is a chain drive unit on the back of the engine, driver side. The chain requires to be changed around 100k which requires pulling the transmission and rear cover.

 

[18CrewDually]

So, what HPFP is used on the GM 3.0?

Here's pics of the RAM 1500 compared to the GM 1500 HPFP.
GM 3.0



RAM 3.0

 

[ramffml]

I believe it uses a Denso pump similar to the HP3. It is a v-twin bore like the Bosch unit 4.2.
It is a chain drive unit on the back of the engine, driver side. The chain requires to be changed around 100k which requires pulling the transmission and rear cover.

Just a minor nit pick, it's belt drive not chain. The belt is bathed constantly in oil and is designed to "get wet", and its a 200k mile change not a 100k mile. Which means you probably only have to change it once in the lifetime of the truck. People freak out about this fact but its a minor inconvenience as far as I'm concerned. It's easy to plan and budget for, just the cost of doing business. If the rest of the truck/engine holds up its well worth the change at 180k (just to be safe).

 

[tjfdesmo]

Just a minor nit pick, it's belt drive not chain. The belt is bathed constantly in oil and is designed to "get wet", and its a 200k mile change not a 100k mile. Which means you probably only have to change it once in the lifetime of the truck. People freak out about this fact but its a minor inconvenience as far as I'm concerned. It's easy to plan and budget for, just the cost of doing business. If the rest of the truck/engine holds up its well worth the change at 180k (just to be safe).

The lube oil pump is belt driven but the fuel pump is chain driven, from what I have read.

 

[18CrewDually]

Just a minor nit pick, it's belt drive not chain. The belt is bathed constantly in oil and is designed to "get wet", and its a 200k mile change not a 100k mile. Which means you probably only have to change it once in the lifetime of the truck. People freak out about this fact but its a minor inconvenience as far as I'm concerned. It's easy to plan and budget for, just the cost of doing business. If the rest of the truck/engine holds up its well worth the change at 180k (just to be safe).

You're referring to the variable OIL pump which is belt drive and has a service life of 150k miles.
The high pressure fuel pump I pictured above is CHAIN driven. The same chain that drives the camshaft through plastic guides and held tight by a tensioner. There's been failures around 120k and less. Typical fashion, just outside warranty.
It starts with a cam/crank sync code.
P0016 -- camshaft / crankshaft position correlation
I'll attach a picture so you can better understand. The belt is the lower one for the oil pump. The chain like I said drives the rest.