My beloved Duramax needs help.

[jjeff]

2016 6.6 Duramax is I'll attempt to make this quick January drove truck 500 + miles to visit my dad, idler pulley and tensioner went out far from home got truck towed to a GM garage only place up there I could find that would touch a modern Diesel. Stubbornly figured since it's in might as well have them replace fuel filter also, last time I did it myself I had to drop fender liner to make sure I'd do it right. Anyways picked truck up was hard starting but eventually fired and the check engine light immediately illuminated. There mechanic drove it into garage hooked up a scanner and believe said it's the map sensor and it was disconnected hooked the harness back did a reset and light went out, so away I went 500 miles home. Stopped to get fuel once and truck was hard starting meaning I cranked the starter for an extended period of time and it wouldn't fire, ie start. Anyways for some time the truck would start pretty easily again so I figured maybe there was air in the lines or something. Fast forward to current situation after sitting for several days truck starts immediately than dies out, after about a minute of running fine, extended cranking of starter eventually gets it to start again and it will run good and stay running until i shut it off, until it sits a few days again. There's no check engine lights or any other warning indicators. So I'm wondering should I call that dealership up and basically complain seeing what they will do if anything? Pull the fender liner check the fuel filter (pia for a non certified backwoods mechanic) myself making sure no o-ring was pinched or similar, or completely bite the bullet and take it to another gm dealership around my home? I have not noticed any fuel leaks or smelled excessive diesel fuel fumes or excessive exhaust. Truck always ran great and still does when it's running.

 

[Hay Dude]

I don’t know what kind of money you have to mess with-thats always a big consideration when these kinds of questions are asked, but I’d install a new fuel filter because its’ cheap, then move on to the next thing. Extended crank usually means air in fuel.

I don’t have the time to screw around, so I usually find the most satisfaction out of taking it to a qualified GM tech and having it fixed properly.

Take heart. It’ll be back to running great soon. I know how ya feel.

 

[jaxs]

I wouldn't approach dealer that worked on it until the problem has been found and solved. If you complain now they will only say bring it to them then regardless what they find they'll say it wasn't caused by what they did before.

 

[5030]

Sounds like air in the fuel to me as well. Dura Max engines are touchy about that.

 

[jjeff]

Ok was on the fence about what to do about this so thank you all for the insight, and I'll admit I'm worse than a "Karen" when i occasionally have others repair stuff for me. If I remember from last time doing it myself that fuel filter assembly has the larger o-ring around the housing and one or two smaller ones in the filter assembly itself if someone that isn't double jointed with small mitts or small enough to crawl in that engine bay to properly change filter without pulling the somewhat cheap fragile fender liner I'm all ears. My pessimistic view of others doing repairs for me says one of the two or three o rings is improperly installed. So I'll aquire a new filter with o-rings beforehand. Fingers crossed.

 

[Deere Dude]

2002 Duramax owner. Has started great for 160k miles. In November I changed the batteries and than a month later I changed the fuel filter. I was able to reach way down to change it so all was good..

A thousand miles later I parked the truck on a hill at home with the front on the up side. It sat for 3 days without moving while emptying a big trailer. I eventually wanted to park it so I turned the key it wouldn't start. It usually would start in half a second but this time I cranked for 5 seconds with a no go. I popped the hood and went right to the fuel filter, opened the bleeder valve and was able to purge a bunch of air out while pumping the push purge button. It took right off then and no more problems since that. You are on the right track I think with o-rings being a possible culprit but in my case it was air that seemed to get entrained someplace. Maybe. Maybe parked in a goofy position didn't help things.

 

[slckeys]

I certainly would not go back to the original dealership, especially since you mentioned you were far from home. Not for the cost of a fuel filter anyways. I'd recommend going to your local dealership and explain what happened. It definitely sounds like a fuel filter issue/losing prime from the fuel filter. There should be a service history of the original dealership working on it in their computer system they can access.

Sounds like it's been a couple months since the original problem, but maybe they'll give a free fuel filter if it's faulty since it was done at a dealership? One can hope right... Good luck

 

[Like Tractors]

2016 6.6 Duramax is I'll attempt to make this quick January drove truck 500 + miles to visit my dad, idler pulley and tensioner went out far from home got truck towed to a GM garage only place up there I could find that would touch a modern Diesel. Stubbornly figured since it's in might as well have them replace fuel filter also, last time I did it myself I had to drop fender liner to make sure I'd do it right. Anyways picked truck up was hard starting but eventually fired and the check engine light immediately illuminated. There mechanic drove it into garage hooked up a scanner and believe said it's the map sensor and it was disconnected hooked the harness back did a reset and light went out, so away I went 500 miles home. Stopped to get fuel once and truck was hard starting meaning I cranked the starter for an extended period of time and it wouldn't fire, ie start. Anyways for some time the truck would start pretty easily again so I figured maybe there was air in the lines or something. Fast forward to current situation after sitting for several days truck starts immediately than dies out, after about a minute of running fine, extended cranking of starter eventually gets it to start again and it will run good and stay running until i shut it off, until it sits a few days again. There's no check engine lights or any other warning indicators. So I'm wondering should I call that dealership up and basically complain seeing what they will do if anything? Pull the fender liner check the fuel filter (pia for a non certified backwoods mechanic) myself making sure no o-ring was pinched or similar, or completely bite the bullet and take it to another gm dealership around my home? I have not noticed any fuel leaks or smelled excessive diesel fuel fumes or excessive exhaust. Truck always ran great and still does when it's running.

2011 thru 2016 GM Duramax fuel systems have a built in problem, the high pressure pumps start grinding themselves up form the first time you start them, eventually you end up replacing the entire fuel system. That system has no pump to supply fuel under pressure to the high pressure pump, during operation the inlet side of that pump runs at a negative pressure and fuel cavitation occurs, which in turns destroys the pump. If you are lucky the fuel filter installation was flawed, if not, trade that son of a ***** off!

 

[Hay Dude]

Or add a larger fuel lift pump.
From what I am hearing, this helps save those pumps.
I just posted a thread about CP3 & CP4 pumps.
most AG tractors running CP4 pumps have a high flow gear pump behind them and have few failures.

IF the lift pump is the problem, why not replace the weak lift pump with a stronger lift pump?
Much cheaper/easier than replacing entire fuel system, right?

Maybe they figure the fuel system is damaged very early during ownership?

 

[mikester]

Trifecta - Bad fuel, fuel filter woes, injector pump failure

Everything is computerized and you need the dealer. I don't miss my Duramax, especially out of warranty issues