Don't run naked diesel

[fireaxxe]

3.0 liter Duramax here was not happy with third fill up. Engine developed a terrible fuel knock just off idle during acceleration up to about 1200rpm and if anyone is wondering what this sound is like, I can only describe is as a gas spark knock or valve "clatter" if the lash is out. So I just drove easy trying to allow the ECU to correct any fuel related issues and the problem got worse. I started getting a rattle like knock pulling off from a stop light. Overall the engine was louder at idle and while running. So I refreshed the CEL with my scan tool hoping to reset the short term fuel settings any any other stored data. I also disconnected the battery.

 

I got it back going and noticed the fuel knock was less noticeable and I got a little throttle response back that I did not realize I had lost.  Still not happy I dug a little further and started looking up information on additives starting with the GM diesel conditioner. Way overpriced . I read the manual and noticed GM specifically says not to add any additives to the fuel or oil. However if you get a less quality tank of fuel you can add their additive. They also gave a clue as to which additives would be the worst. Those with emulsifying properties and that have alcohol added are specifically mentioned as DO NOT USE. 

 

I purchased a gallon of Stanadyne Diesel fuel additive and added 7 oz. to the tank, which was still pretty much full. Shook the truck as best I could to mix it in, before I went for a spin. I also reset the CEL again (Never had a CEL but my scan tool only resets the ECU with this function) and started it up. The first ten miles still had fuel knock but no rattle from idle. Drove it about 50 miles and the fuel knock is gone, my fuel milage is back up, and the engine is very quiet like the day I brought it home. 

 

I have had two other diesel trucks and both I always kept an additives in. Those engines were so loud I couldn't really tell if these additives had a real effect  on sound, but would often notice fuel milage increases and changes in the smoothness if the engine. One was a 7.3 liter IDI Ford and the other was a 6.2 liter Chevy. I hated them both. When I got this 3.0 liter I was so impressed and very happy to be back in a diesel that pretty much solved all the problems I could not stand about diesels. And very disappointed that a bad tank of fuel brought must of the negative characteristics back. So if you want to keep your 3.0 liter Duramax happy along with yourself do not run naked diesel. 

[JimCost2014]

Good info, thanks for sharing.

 

Think I would like the title of the post if it were more of a PSA, Don't run naked, Diesel!!!

[Pawg]

I think you just got a shitty tank of fuel.  I am sure you do, but always go to a high volume station gas or diesel.   Yes, I do believe in lubricity and water reducing additives regardless of what the manufacturers say.  THey are just worried about emissions.

[KARNUT]

I had lots of diesels especially during the 90s. It wasn’t surprising to get bad fuel. Water or gas can cause that reaction. Usually water triggers a light. I even got gas from a diesel pump. Luckily that truck had two tanks. Probably just bad fuel.

[Black02Silverado]

I google searched naked diesel and didn't find anything other than post about Vin Diesel naked.

 

So what is it?

[Grumpy Bear]

49 minutes ago, Black02Silverado said:

I google searched naked diesel and didn't find anything other than post about Vin Diesel naked.

 

So what is it?

 

 

Your funny Nick

[fireaxxe]

1 hour ago, Black02Silverado said:

I google searched naked diesel and didn't find anything other than post about Vin Diesel naked.

 

So what is it?

Haha, it’s just my way of sayin diesel without additives or straight from the pump with no treatment 

[fireaxxe]

6 hours ago, Pawg said:

I think you just got a shitty tank of fuel.  I am sure you do, but always go to a high volume station gas or diesel.   Yes, I do believe in lubricity and water reducing additives regardless of what the manufacturers say.  THey are just worried about emissions.

Yes I’m sure! It was a lot better when I reset the ECU but after a few days I have a little valve chatter that’s back. No where near as bad. Like 20% of what it was. I drained the filter and no cloudy diesel or water came out just perfectly clear fuel, so I’m thinking it’s mixed with a little gasoline. Question is what’s the damage? I might drain out this tank send a sample to Blackstone and keep my receipt just in case. Still No CEL which is good for now. 

[Black02Silverado]

10 minutes ago, fireaxxe said:

Haha, it’s just my way of sayin diesel without additives or straight from the pump with no treatment 

OK now I see.  I always put in AMSOIL's Diesel Injector Clean with Cetane Boost when I fill up my 2014 Chevy Cruze diesel.

[Rob Mugs]

I have never once added anything to any diesel.  Shocked you had issues with the 7.3.  While a very noisy engine, it doesn't even truly break-in until 400k miles.  Replaced the injectors once but all I can think about really 

[KARNUT]

33 minutes ago, Rob Mugs said:

I have never once added anything to any diesel.  Shocked you had issues with the 7.3.  While a very noisy engine, it doesn't even truly break-in until 400k miles.  Replaced the injectors once but all I can think about really 

My mother yes, mother drives a one ton 2000 Ford with the 7.3 bought new. Her second vehicle is my late fathers 98 dodge diesel. She wouldn’t drive anything else. She’s 83. She could drive anything doesn’t want to. She drives almost daily. Oh yea, naked diesel fuel too.

[fireaxxe]

1 hour ago, Rob Mugs said:

I have never once added anything to any diesel.  Shocked you had issues with the 7.3.  While a very noisy engine, it doesn't even truly break-in until 400k miles.  Replaced the injectors once but all I can think about really 

Don’t get me wrong it was bullet proof. But hated the noise, 0-60 in 20sec times and the diesel funk.

[Grumpy Bear]

2 hours ago, Rob Mugs said:

I have never once added anything to any diesel.  Shocked you had issues with the 7.3.  While a very noisy engine, it doesn't even truly break-in until 400k miles.  Replaced the injectors once but all I can think about really 

 

Ah! Someone that understands 'break in" and wear! 

[Rob Mugs]

3 hours ago, fireaxxe said:

Don’t get me wrong it was bullet proof. But hated the noise, 0-60 in 20sec times and the diesel funk.

It's a diesel... it could pull a 100 year old redwood out of the ground but 0-60 and quiet... oh and no "funk"?  Not so much; wasn't what it was designed for.  It's a working man's truck, not a caddy

 

That said, you could get a ton of power out of them IF you wanted to spend the money to build the motor AND trans.

 

 

[Fletch379]

On 8/5/2021 at 10:07 AM, fireaxxe said:

3.0 liter Duramax here was not happy with third fill up. Engine developed a terrible fuel knock just off idle during acceleration up to about 1200rpm and if anyone is wondering what this sound is like, I can only describe is as a gas spark knock or valve "clatter" if the lash is out. So I just drove easy trying to allow the ECU to correct any fuel related issues and the problem got worse. I started getting a rattle like knock pulling off from a stop light. Overall the engine was louder at idle and while running. So I refreshed the CEL with my scan tool hoping to reset the short term fuel settings any any other stored data.

I have the same issue with my 3.0L. Fuel knock is horrible, even more so when it's trying to regen. The manual supplement states this engine is designed for Top Tier Diesel which is sold at select retailers, none of which are anywhere close to me. GM only recommends their diesel fuel supplement which is a joke, none of the dealers around me have it in stock and is way over priced. I use Opti-Lube Boost which is Cetane and lubrication only. It helps but does NOT eliminate it. Very Frustrating but not nearly as frustrating as having multiple CEL issues and the dealer not being able to find the root cause. Trucks has been at the dealer for weeks now and will likely be there a few more. I have called GM and this has supposedly be escalated to their senior service team for whatever that's worth. No communications from them either. I do know the codes are emissions related. Supposedly there is a service bulletin but the troubleshooting is fairly extensive. Truck has 6500 miles on it. ANY ideas of how to get GM's attention to help solve my problem would be greatly appreciated... I'm new here so please keep the heckling to a minimum..LOL