Injection pump exploded

[Fr8Pilot]

This is my first post here although I've been reading for some time. Found some really useful information here.

I have an LB7 01 Chev Silverado CC that is all stock. Just the other day, I started it up and I heard some irregular clicking and metal clanking noise from the engine compartment. Then normal. I backed it out of the garage and look under the hood and noticed a fuel trail on the driveway. Underneath, fuel is pouring out from the back of the engine/transmission area on the passenger side. That's not a good sight.

After poking around and removing several assemblies out of the way, I found the engine valley full of fuel. Hoping that it would only be a fuel return line loose or off, I dig deeper and find one of the HP pumps blow out plugs on the valley floor. Uh, not good again. So I spend all day removing the injection pump and sure enough, it shucked its innards. There were all sorts of metal pieces beneath the pump.

Has anyone had this happen? And what do you think caused it? I have used Stanadyne's lubricity formula but only occasionally. Although GM says the Dmax is designed to operate with todays low sulfur diesel, could this have accelerated the pump's demise? Now I have to inspect and clean the injectors, fuel lines, fuel rails, etc. to get whatever metal particles traveled through there. I had no previous problems with this truck and no warning this was coming. All total, the truck ran only 30 seconds to less than a minute from start up, metal noise, fuel leak to shut down.

I know now where I'll be spending my economic stimulus payment from the IRS. Just great.


Freight Pilot


2001 Chevrolet Silverado CC 2500HD, Pewter, stock 6.6 DMax.

[Duramaster]

It's my understanding that water (LOTS OF WATER) in the fuel causes the pump to explode. I know from experience that on the DMAX's that I work on under warranty, GM wants us to REPLACE the: pump, filter head, both fuel rails, all injectors and clean out the entire fuel system which means removal of the fuel tank. You will also notice metal particles in the sender itself which are visible through the clear tubing in the sender.

[Fr8Pilot]

The fuel system did not have any water that I know of. Wouldn't the water sensor pick this up and even if there was water in there, wouldn't the filter itself stop the water from going through? I've called several shops here in eastern Idaho and Utah and they haven't seen one blow metal parts out of the plug holes. One of the pistons inside the pump appears to have simply come apart. It makes sense that water could cause this but how did that much water get in there without any prior indication? Flushing the lines, rails and injectors should be sufficient to clean any debris and/or water.

Also, any ideas on where I can get my hands on a rebuilt/reman Bosch CP3 pump? I was under the impression that these pumps were almost bullet proof. Mine only has 95K miles on it but the truck is 7 years old so out of warranty. The injectors should still be covered for about another month. Is it possible to still get warranty coverage on injector replacement when I'm doing the work myself? My guess is no.

Freight Pilot


2001 Chevrolet Silverado 2500HD CC, Pewter, Stock LB7 6.6L DMax

[SoTxPollock]

FR8PILOT, how many miles did the pump have on it? Did you fuel up at a strange station? I'd pull a fuel sample and send it to a lab for analysis, that is scarey.

I fell sure from his posts Duramaster knows his stuff, but how could one get that much water to the pump, surely you are running the correct filter that separates the water.
Keep us informed, your truck is only a year older than mine. This is the first I heard of the fuel pump coming apart like that.

[Fr8Pilot]

This is the original pump on the truck. A few months ago, I picked up fuel in Laramie, WY and 75-100 miles later the truck went into limp and the SES light illuminated. I don't know what the code was as I don't have a reader yet but was able to reset the limp mode. I could drive for another 50 or so miles and the SES light came back on and truck would limp again. It did this until I ran most of the fuel out and refilled with fresh diesel in Kansas whereupon the SES light and limp problem went away. I continued on to Houston where I spent three weeks driving around town with no problems. I did change the filter while in Houston. On the return trip back to Idaho Falls, I again stopped for fuel in a different city in Wyoming and again limped after 75-100 miles. I initially suspected fuel gelling because the temp was around 5F but I had driven around Idaho Falls where the temp was as cold as -18F and had no issues at all. The only common thing here is WY fuel.

I'm wondering if I picked up very bad fuel in WY and this is the cause of my fuel pump problems after three months of normal driving here in Idaho Falls.

Freight Pilot

2001 Chevrolet Silverado 2500HD, Pewter CC, Stock LB7 6.6L DMax