2006 GMC Sierra K1500 - Fuel Filter

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Hi,

It seems the fuel filter is not a maintenance item on this vehicle. I changed the one in my old 1996 K1500 every 30k, it was mounted on the driver side frame rail roughly below the rear of the cab. This new truck doesn't have one that I can see. Is it now a part of the fuel pump in the tank and is it good for life?

Thanks,

Marc
 
Originally Posted By: marc1
Hi,

It seems the fuel filter is not a maintenance item on this vehicle. I changed the one in my old 1996 K1500 every 30k, it was mounted on the driver side frame rail roughly below the rear of the cab. This new truck doesn't have one that I can see. Is it now a part of the fuel pump in the tank and is it good for life?

Thanks,

Marc

I don't know for sure about your vehicle, but my 05 Trailblazer was like that and since your GMC is an 06 that doesn't surprise me. No replaceable fuel filter.
Some of the parts store will have it wrong and show a filter, but the only filter is a "sock" type on the pickup of the fuel pump in the tank - which is suppose to be good for life.

I was first told this by members over at Trailvoy and I was a little skeptical so I crawled under my Chevy and double checked. Sure enough there wasn't an external filter anywhere on the line from the tank up to the engine.

Also on the Trailblazer (I6 engine) there is no fuel pressure regulator - the fuel pump is a "pulse width modulation."
 
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I had an 04 Avalanche. Only filter is in the tank (sock style as mentioned) at the fuel pump. You change the filter when the fuel pump fails.

They changed them over in '03 IIRC and after that year, no more external fuel filters like on your '96 K1500 (or my previous '98 K1500).
 
Agree with all the replies. My 2006 Sierra fuel filter is inside the tank.

These filters are large capacity, supposedly three times the dirt holding capacity of a regular fuel filter. The pump is not PWM, there is a mechanical pressure regulator that dumps excess pressure right back into the tank.

The filters are also designed to be self-cleaning to an extent. When the pump turns off, some of the trapped dirt falls off the filter to the bottom of the tank.

Fuel is a lot cleaner than they were twenty years ago. That is why manufacturers are going maintenance-free on fuel filters.
 
Originally Posted By: George7941
The pump is not PWM, there is a mechanical pressure regulator that dumps excess pressure right back into the tank.

The filters are also designed to be self-cleaning to an extent. When the pump turns off, some of the trapped dirt falls off the filter to the bottom of the tank.

Fuel is a lot cleaner than they were twenty years ago. That is why manufacturers are going maintenance-free on fuel filters.

The pump in the Sierra may not be PWM, but the one in my Trailblazer was and my vehicle does NOT have a fuel pressure regulator - believe me I looked and compared it to the 2002 - 2004 Trailblazer/Envoy models. I'd be surprised that the Sierra is any different.
 
The PWM pumps are probably the ones driven by a fuel pump driver module. If you look under your Trailblazer, close to the fuel tank, you should find the module.

The one in the Sierra is NOT PWM, I am positive. I have the GM service manuals and the wiring diagrams. I have also scoped the fuel pump current. In fact I check on the fuel pump current about twice a year just to monitor its health. GM fuel pumps, and the GM truck pumps in particular, are notorious for failing, and I don't want to be stranded on the side of the road from a failed fuel pump.
 
Originally Posted By: George7941
The PWM pumps are probably the ones driven by a fuel pump driver module. If you look under your Trailblazer, close to the fuel tank, you should find the module.

Can't do that! If you note in my signature that vehicle has been sold.

Quote:
The one in the Sierra is NOT PWM, I am positive. I have the GM service manuals and the wiring diagrams. I have also scoped the fuel pump current. In fact I check on the fuel pump current about twice a year just to monitor its health. GM fuel pumps, and the GM truck pumps in particular, are notorious for failing, and I don't want to be stranded on the side of the road from a failed fuel pump.


I'll take your word for it - I just find it odd that GM didn't do the same on their trucks as they did my SUV. Of course knowing GM maybe I should rethink that statement.
I'd agree also GM truck pumps are not know for their longevity!
 
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Originally Posted By: George7941
The PWM pumps are probably the ones driven by a fuel pump driver module. If you look under your Trailblazer, close to the fuel tank, you should find the module.

The one in the Sierra is NOT PWM, I am positive. I have the GM service manuals and the wiring diagrams. I have also scoped the fuel pump current. In fact I check on the fuel pump current about twice a year just to monitor its health. GM fuel pumps, and the GM truck pumps in particular, are notorious for failing, and I don't want to be stranded on the side of the road from a failed fuel pump.


How do you go about doing this procedure?
 
Originally Posted By: George7941
GM fuel pumps, and the GM truck pumps in particular, are notorious for failing, and I don't want to be stranded on the side of the road from a failed fuel pump.


As a fleet owner who only buys GM trucks I must dispute this. If I only had one or two I wouldn't pay any attention, but I haven't replaced a fuel pump in DECADES of owning quite a few Savanas and Silverados.
 
I had a fuel pump failure on my '98 K1500 in 2000. I was the second owner, and the first owner had never changed the fuel filter. The dealership told me it was nearly clogged when they replaced the pump. To be fair, the truck had 120k miles in its first 3 years before I bought it. Probably on the same fuel filter. That took out the pump.

When I was active on the bulletin boards for this truck, it was a fairly common occurence for this series of GMs, even with good maintenance.
 
Originally Posted By: bigmike

How do you go about doing this procedure?


You need an oscilloscope to do it. The graph will display the current drawn by each commutator segment in the pump motor and any degradation will show up in the waveform. Bent shaft or loose/ partially seized bearings will also show up.

Will this method predict failures with 100% accuracy? No. But,IMO, it will catch the majority of failures.

In the absense of a scope you could at least measure the current draw with a multimeter, and once you know what the normal draw is, any abnormally high or low current can be investigated.
 
Originally Posted By: SteveSRT8
Originally Posted By: George7941
GM fuel pumps, and the GM truck pumps in particular, are notorious for failing, and I don't want to be stranded on the side of the road from a failed fuel pump.


As a fleet owner who only buys GM trucks I must dispute this. If I only had one or two I wouldn't pay any attention, but I haven't replaced a fuel pump in DECADES of owning quite a few Savanas and Silverados.


Well with all due respect you must be the luckiest GM owner around. From what I saw of my 4 years over at Trailvoy it seems to be a fairly common failure item and also in my decades of working on cars I have changed quite a few GM electric fuel pumps.
The most recent one was a family member's Astro van. They bought it new and the pump died around 100K or about 5 years. The cheap replacement pump (which I try to convince them not to buy) lasted about a month longer than the 1 year warranty.

At Trailvoy most people replaced the pump assembly because either the pump failed or the sending unit on the pump assembly quit. For most of us it was between 70K - 100K miles or about 5 years but there were some people that had problems around the 35K mile mark. Yes you can replace the pump itself but most of us just bought a new assembly that included the pump since it was a pain to drop the tank.

I'm not trying to bash GM here just stating what my experience has been. On the other hand I used to tick a lot of people off over at Trailvoy when I mentioned my 16 year old Ford van with over 200K miles still has the original pump and works greats!

Edit: Also GM had a recall on the early model SUV's (2002-2003 Trailblazer, Envoy, Rainer, Bravada) In areas where they had a lot of snow, the top of the pump assembly would rust through and leak fuel.
 
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Ok thanks for all the replies. My 1996 had a fuel pump failure at 90k so I am sensitive to this. However it seems I just have to hope for the best on this new design in my 2006.
 
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