Diesel in gas

[Doug Sage]

This is kind of a long story but here goes. I was in the Salt Lake City area on June 24th and put 44 gallons of unleaded gas in my 75 gallon gas tank. I have a Workhorse chassis with the 8.1 liter gas engine. I then headed east up the Wasach mountains and noticed that my power was down a lot. I was also getting some kind of knocking such as backfiring or engine knock. I barely made it to the top of the pass but then it seemed to be slightly better so I made it to Vernal Utah. It was hot, in the 90s, so I thought that might be a factor too. We spent several days in Vernal and then we filled up the gas tank again and headed out. It was only about 70 out and the road was fairly flat so I had hopes that the engine would run better. Unfortunately, within 10 miles I knew we still had a major problem. I called CoachNet and they recommended that I have it towed to a Workhorse service center. I did that and was towed 110 miles to Grand Junction Colorado. The service center could not find any codes in the computer and checked a lot of other things. They finally decided to change the fuel filter which had never been changed in 40,000 miles. That seemed to help. I continued to tour Colorado for two months and continued to put more gas in the tank and the motorhome ran like it should run. We then headed back toward Portland and stopped in the Salt Lake City area again. It is now two months later so I figure it is okay to stop at the same Flying J as before because they would have gone through several tanks of gas by then. Because of the layout of the station and the size of my motorhome, there is only one pump that I can get into and it is on the end of the row. This is the same pump that I used two months ago. Anyway, I put another 42 gallons of unleaded in the tank and have the receipt to prove it. Away we go toward Idaho and about 80 miles later the very same knocking starts up. I can feather the throttle and keep it around 2200 rpms and be okay but if I need to give it more power or rev above 2500 rpm then it knocks badly. I made it to Mountain Home Idaho and took it to a mechanic and had them replace the fuel filter again since that seemed to work the first time. They said the filter was clean and unrestricted but when they tried to blow through it they noticed a strange odor. They asked if I had put diesel in the gas tank. I had not and had the receipt to prove it. They suggested that I put some Techron fuel additive in the tank and maybe even put in some Supreme grade gas. Their theory was that I got unleaded fuel that had some diesel in it. They don't think I got 42 gallons of diesel because the engine would not have run on that strong of a mixture. I put the Techronn in and about 15 gallons of Supreme and continued to head for Portland. Now I am in the Portland area and have traveled almost 800 miles since filling up in SLC. I have also put 120 gallons of gasoline in since then. After the last fillup here in Portland, I drove for about 3 miles to empty out the gas lines and get the new gas to the engine. I am still getting the knocking! I have talked to several repair shops and no one knows what to do for sure. These are the possible solutions. 1. Keep putting in Techron and Supreme gas until it works out. 2. Maybe the injectors are contaminated and need to be either cleaned or replaced. 3. Maybe the catalytic converters are plugged. Test the pressure and possibly replace. So I am finally to my question. Has anyone ever experienced this and can anyone tell me what to do to fix it so I can again drive my motorhome without it knocking? I sure hope I haven't burned the exhaust valves or knocked a hole in a piston.

[Maddawgs]

Originally Posted by Doug Sage

This is kind of a long story but here goes. I was in the Salt Lake City area on June 24th and put 44 gallons of unleaded gas in my 75 gallon gas tank. I have a Workhorse chassis with the 8.1 liter gas engine. I then headed east up the Wasach mountains and noticed that my power was down a lot. I was also getting some kind of knocking such as backfiring or engine knock. I barely made it to the top of the pass but then it seemed to be slightly better so I made it to Vernal Utah. It was hot, in the 90s, so I thought that might be a factor too. We spent several days in Vernal and then we filled up the gas tank again and headed out. It was only about 70 out and the road was fairly flat so I had hopes that the engine would run better. Unfortunately, within 10 miles I knew we still had a major problem. I called CoachNet and they recommended that I have it towed to a Workhorse service center. I did that and was towed 110 miles to Grand Junction Colorado. The service center could not find any codes in the computer and checked a lot of other things. They finally decided to change the fuel filter which had never been changed in 40,000 miles. That seemed to help. I continued to tour Colorado for two months and continued to put more gas in the tank and the motorhome ran like it should run. We then headed back toward Portland and stopped in the Salt Lake City area again. It is now two months later so I figure it is okay to stop at the same Flying J as before because they would have gone through several tanks of gas by then. Because of the layout of the station and the size of my motorhome, there is only one pump that I can get into and it is on the end of the row. This is the same pump that I used two months ago. Anyway, I put another 42 gallons of unleaded in the tank and have the receipt to prove it. Away we go toward Idaho and about 80 miles later the very same knocking starts up. I can feather the throttle and keep it around 2200 rpms and be okay but if I need to give it more power or rev above 2500 rpm then it knocks badly. I made it to Mountain Home Idaho and took it to a mechanic and had them replace the fuel filter again since that seemed to work the first time. They said the filter was clean and unrestricted but when they tried to blow through it they noticed a strange odor. They asked if I had put diesel in the gas tank. I had not and had the receipt to prove it. They suggested that I put some Techron fuel additive in the tank and maybe even put in some Supreme grade gas. Their theory was that I got unleaded fuel that had some diesel in it. They don't think I got 42 gallons of diesel because the engine would not have run on that strong of a mixture. I put the Techronn in and about 15 gallons of Supreme and continued to head for Portland. Now I am in the Portland area and have traveled almost 800 miles since filling up in SLC. I have also put 120 gallons of gasoline in since then. After the last fillup here in Portland, I drove for about 3 miles to empty out the gas lines and get the new gas to the engine. I am still getting the knocking! I have talked to several repair shops and no one knows what to do for sure. These are the possible solutions. 1. Keep putting in Techron and Supreme gas until it works out. 2. Maybe the injectors are contaminated and need to be either cleaned or replaced. 3. Maybe the catalytic converters are plugged. Test the pressure and possibly replace. So I am finally to my question. Has anyone ever experienced this and can anyone tell me what to do to fix it so I can again drive my motorhome without it knocking? I sure hope I haven't burned the exhaust valves or knocked a hole in a piston.

I think (and I could be wrong) that you got a batch of bad gas or the tank you pumped from is fouled with to much sediment or water moisture (could also mistakenly caught a few gallons of diesel-but I doubt it). Most of this would have got caught in the filter that you had changed. the rest washed thru your system as you went thru a few tanks. You could have clogged injectors so I would suggest some Gumout fuel injector in your next fill up. Another cause for the knocking could be the premium or supreme high octane gas. This will cause knocking in engines not designed for it. Hope this helps you out.
Todd
Todd

[windydaboo]

I'm not sure what yr. your coach is and going by your description of events leads me to believe you picked up some bad fuel. Have you contacted the station to see if others may have had the same issue as you?
With a clogged cat you would see a loss of power and I doubt it would clear up and come back. You may have a bad O2 sensor that has yet to spring a code to the ECM. Some vehicles (not sure if your does) have 2 O2 sensors, one before and another after the cat. I have had a bad O2 that didn't throw a code before. A bad injector could also be the issue or even a spark plug and/or wire. By going by your description though, it sounds fuel related. Unfortunatly, some of these possibilities require throwing parts at it to see if they work. A good diagnostic shop or the dreaded dealer may be in the cards for you.
Good luck and let us know what you find out... Jason

[Doug Sage]

My signature shows that I have a 2007 Itasca Suncruiser. I have talked to the gas station manager and a claim has been started but they are currently not making any admissions.

[LVJ58]

Have you checked your #5 & 7 plug wires, I've read some posts where folks have had those plug wires burned from inadequate air flow around the engine. Just a thought, also symptoms you describe may be engine timing related due to a faulty crank sensor and/or a faulty PCM, but not sure...anyway a place to start checking.

Good luck ferreting out your problem and do keep us posted on the fix..

[Shadowcatche]

We had two instances of bad gas on our 3,000 trip this summer towing our teardrop. Our 3L Subaru prefers premium and in a couple of instance the smell of alcohol and the really bad gas mileage was indicative.

[Fred and Bonnie]

Originally Posted by Shadowcatche

We had two instances of bad gas on our 3,000 trip this summer towing our teardrop. Our 3L Subaru prefers premium and in a couple of instance the smell of alcohol and the really bad gas mileage was indicative.

Thank You Uncle Sam and the Ethanol program.
Possibly E85 gas designed for Flex-Fuel vehicles.

fred

[Doug Sage]

Originally Posted by LVJ58

Have you checked your #5 & 7 plug wires, I've read some posts where folks have had those plug wires burned from inadequate air flow around the engine. Just a thought, also symptoms you describe may be engine timing related due to a faulty crank sensor and/or a faulty PCM, but not sure...anyway a place to start checking.

Good luck ferreting out your problem and do keep us posted on the fix..

I have had the plug wires replaced and the cold air vents added previously. It doesn't feel like that problem.

I am wondering if I do have an engine timing issue but I think it might be because of very low octane due to the diesel contamination of the gasoline.

[autofish]

Sage .........years ago I had kid fill my car with diesel without me knowing, Only had to drive about .3 mile and the car started to knock real bad so went back to gas station and they relized they made a mistake. So they drained my tank and filled it up with gas and sent me on may way, the car took 3 or 4 more tanks of refills befor it stared to run good again, In the end no harm done----------

[Arch Hoagland]

Had a friend who filled his Chevy work truck with diesel that had been put in the gas storage tank. He made it 80 miles to his next account and when he shut off the engine it never started again.
The gas station paid for repairing his and all the other vehicles that filled up there that day. So it can happen.
That was several years ago and he is still driving the truck so it can be cured.

[EngineerMike]

Diesel in the gas is easier than gas in the diesel, so I'm told. A buddy just did that w/his toad. They pumped out the tank, refilled, it ran poorly but recovered.
IIWM@ this stage, I'd add octane booster & Techron additives.
But I'd be worried about the cataclysmic converter as its not built for that. Seems like it'd throw an O2 sensor code.

[RoadHogg]

Originally Posted by EngineerMike

Diesel in the gas is easier than gas in the diesel, so I'm told. A buddy just did that w/his toad. They pumped out the tank, refilled, it ran poorly but recovered.
IIWM@ this stage, I'd add octane booster & Techron additives.
But I'd be worried about the cataclysmic converter as its not built for that. Seems like it'd throw an O2 sensor code.

Correct. Diesel fuel won't hurt your gas engine the way gas will damage a diesel engine. Cat converters may get gunked up from the diesel though.