HELP !-Wife put diesel in my gas engine! - PeachParts Mercedes-Benz Forum

mbdad · #1 12-27-2002, 06:38 PM

I posted this question under the Tech forum, but perhaps someone more familiar with diesel fuel can help.
My wife took my car to work today. She stopped to put gas in it. She says that she put in about a dollars worth of deisel before she realized it. In a panic, she put in only $4 dollars worth of gas and drove home.
What should I do?

#2 12-27-2002, 06:41 PM

a dollar worth of diesel? I just might go and fill it up with premium and keep driving it. I don't think it's enough to worry about.

#3 12-27-2002, 06:49 PM

Less than a gallon of diesel will not hurt the engine. It MIGHT, do something to the O2 sensor, and possibly to the fuel filter. Although I do not think so.
If after the fuel is all used up, you notice the car don't idle well, start with changing the fuel filter, then go to the O2 sensor.

lrg · #4 12-27-2002, 07:44 PM

A gallon in a 18-20 gallon tank shouldn't hurt. It may foul your plugs a little but they should clean up by themselves over time. If you haven't already filled the tank with gas do it right away, you want to dilute the diesel as much as possible. Premium is unnecessary as the diesel won't lower the octane rating(it may actually raise it). The filters should be fine and unless you're getting black smoke coming out of your tail pipe (I doubt you will) the O2 sensor should be fine too. There is no lead in diesel so the Cat shouldn't be affected either. The diesel may make the car a bit harder to start when cold but otherwise, given the small amount, will likely just burn up with the car feeling like you got a load of bad gas (which in essense you did).

leathermang · #5 12-27-2002, 08:05 PM

Fill it up with actual gas and forget it ... My father put a tankful into his 95 Crown Vic... LOL.. it would not run on it.. I took five five gallon cans and syphoned it out.,,,put five gallons gas in ... and after a few cranks it started and acted like nothing had happened.... Drove it five years after that and sold it still going strong.....

Gilly · #6 12-27-2002, 08:19 PM

How did she get the Diesel nozzle to go in through the restrictor for the unleaded fuel? Cars in the US (gasoline engine) have had these restrictors since the mid-70's, there should be no way you can put anything in that tank other than no-lead gas. If they have a Diesel pump with an unleaded pump handle on it, you better tell them to change the nozzle or report them to whever handles that type of thing, consumer protection or something.

Gilly

#7 12-27-2002, 08:29 PM

My dad put 31 gallons of diesel into the Blazer once, and it ran fine once the fuel was drained out and replaced with gasoline.

mbdad · #8 12-27-2002, 08:31 PM

Thank you all for your replies. I will fill the tank first thing in the morning.
I did ask my wife how she got the diesel nozzel into the gas filler. She said that it would not go in so she had to hold it so the hole of the nozzle was over the gas filler. That's how she realized something was wrong.

#9 12-27-2002, 08:35 PM

I hate to say it but that ford 4.6 V8 is almost as durable and reliable as the MB 617. Great engine.

Gilly · #10 12-27-2002, 08:53 PM

I bet she smelled like fuel oil the rest of the day! Phew! :x(

Gilly

Mike123 · #11 12-27-2002, 09:33 PM

A business associate's wife filled their Cadillac with diesel. She had never filled the car before and probably never will again. The place she usually went had full service, but was not open that evening. She then ran the car until it died. He said it cost him $2500.00! I suspect the dealer repair shop may have piled on a bit. She, too, had difficulty filling the tank, but due to her inexperience, did not know that the fuel nozzle should fit fully into the tank filler.

84300DT · #12 12-27-2002, 09:49 PM

mbdad,
around here $1 buys about 1/2 gal of diesel - just fill with gas and drive.

P.E.Haiges · #13 12-27-2002, 11:43 PM

Contrary to what IRG says, the Diesel fuel will reduce the octane rating of the gasoline. But the small amount will not hurt anything. Filling the tank with gasoline will dilute the Diesel and there will be little change in the octane rating of the mix.

There is no reason that the Diesel fuel will have any effect on the fuel filter.

P E H

lrg · #14 12-28-2002, 02:27 AM

P E H,
Please elaborate. In the simple explaination (I don't want to get into a big discussion about octane ratings) octane rates the tendancy of gasoline to resist ignition (and therefore pre-ignition). Since diesel is less volatile than gasoline I'd reason that a (very) small amount of diesel added to gasoline would make it slightly less volatile/prone to pre-ignition and therefore effectively higher octane. What am I missing?

Gilly · #15 12-28-2002, 09:05 AM

...Or give her a funnel as a late Christmas present so it's easier for her to misfuel the Benz. The guy in the Kenworth waiting behind her in line (laughing) wasn't clue enough?
(Just kidding, no coffee yet and feeling mean)
I tend to agree that this would tend to somehow raise the octane, not lower it, but wouldn't recommend trying it on purpose.

Gilly