Did Gasoline in Tank for 25 Miles Do Damage? - PeachParts Mercedes-Benz Forum

shertex · #1 12-14-2009, 11:15 AM

I've been reading various threads about people who mistakenly put gas in the tank....am curious to know the likelihood that any real damage was done in my situation.

Daughter stopped to refuel with just under 1/4 tank left. Unknowingly filled up with gas. Drove 25 miles before things sputtered and died. This is the 1992 300D.

What's at risk in a situation like this?

What's the likelihood of damage?

If there has been damage, will this be readily apparent to a tech who knows what he's doing, or could the damage be non-symtomatic for some period of time?

Thanks.

junqueyardjim · #2 12-14-2009, 11:32 AM

Twenty five miles on that much gas certainly is no good. First thing I would do is get the gas/diesel out of it and put in straight diesel, also replace the fuel filters and typically if you do that with the rear end elevated you can run the fuel out of the fuel lines also. Then start it up and see what it sounds and smokes like. Before starting I would just check the engine oil. Probably no dilution, but it is easy to check. Did the driver give much information on how the car ran those 25 miles? Did it overheat? Did it stop running when it overheated? If it didn't overheat you might have escaped terminal damage. I think it will be apparent to anyone interested in an auto engines very soon if major damage was done.

kerry · #3 12-14-2009, 11:55 AM

Having read many threads on this topic over the years, if it were me, I'd drain the tank, fill with diesel and continue on with my life. If it runs ok, there's no further damage that will be done. Obviously, if it won't run or won't run well you may have to make some decisions but my guess is that it will run fine.

Of course, the first thing I would do is to have 'Are you sure it is diesel?' tattooed on the back of my daughter's right hand.

oldsinner111 · #4 12-14-2009, 01:06 PM

More than likely,the gas cleaned years of diesel slime off tank,and float.Screen and or filters clogged stopping vehicle.Drain,add fresh diesel, in fuel filter too.

barry123400 · #5 12-14-2009, 07:11 PM

There are no absolutes in this area. I have seen people run the full tank through their engine at your approximate mix ratio with no real observable damage. Plus a tractor develop serious mechanical issues in a block or so on gas.

If the engine runs well again after cleaning the system out I would expect no residual hidden damages of any consequence. More might depend on why the engine stopped. Our offspring just seem to test us from time to time.

cessna5354 · #6 12-14-2009, 07:31 PM

I am in uncharted waters, but at what speed was the 25 miles driven? and what damage has/could have been incurred with the injection pump. Gasoline provides no lubrication to the pump, What damage could have been done.

Having said this, I do hopefully that this is of no consequence and your engine has many trouble free miles in its future...

Gary

Codifex Maximus · #7 12-14-2009, 07:45 PM

Quote:

Originally Posted by oldsinner111

More than likely,the gas cleaned years of diesel slime off tank,and float.Screen and or filters clogged stopping vehicle.Drain,add fresh diesel, in fuel filter too.

I'm inclined to agree with oldsinner on this one. Also, what fuel did manage to get thru the filters was not thick enough to be pressurized by the injection pump.

Possibly vaporlock at the lift pump as well?

layback40 · #8 12-15-2009, 09:28 AM

All you can really do is flush the petrol out, change the filters & hope for the best. Once its had a run on proper diesel you will soon know if the IP is ok.
I once put diesel in a petrol car, it was hot & started, when I got home & turned it off, it continued running, had to stall it.

JimSmith · #9 12-15-2009, 10:48 AM

There is no cause for alarm. First, the fuel in the filter, and line from the tank is what got your daughter most of the 25 miles. That stuff was essentially uncontaminated for a good bit of the miles, and then the fuel in the filter got progressively more diluted with gasoline. Mercedes Benz allows up to 50% gasoline dilution of the Diesel fuel for operating temperatures below -20C and implies below -22C you are on your own. At that point the engine output drops, according to MB, in proportion the percent of gasoline in the mixture.

So, your daughter exceeded the maximum allowable mixture at the point where the car stopped running. My father-in-law did the same thing once. Drain the tank and refill with Diesel. Like others have said, change the main and prefilters. When changing the main filter I usually fill it with RedLine or some other mostly Diesel fuel containing additive as I do not have a handy tank of fresh Diesel around for this task. This helps minimize the priming effort, which is tough on your hands if you have the original priming pump.

I would not worry. My father-in-law's car is still running fine about 80,000 miles later.

Jim

I reread the German owner's manual I have after reading a few other posts on the dilution rates and the recommendations are a bit contradictory. At temperatures down to minus 22 degrees C, the allowable gasoline levels should not be allowed to exceed 30% due to concerns with pre-ignition as the flash temperature of the gasoline is much lower than the Diesel fuel, which can lead to excessive compression and damage to the working parts of the engine (higher than design loads for rods, bearings, pistons, head, head bolts, head gasket). There is a specific "exception" at the end of the page that says once temperatures get below minus 22 degrees C, there can never be more than a 50% dilution of the Diesel fuel with other fuels (kerosene, gasoline or anything else). By the way, the pre-ignition concerns sound like the addition of gasoline can help get a Diesel started as it lowers the temperature needed in the cylinder to light off the fuel, which sounds like a beneficial effect for older, aging engines that otherwise don't want to start in colder weather.

A conservative reading of the manual would agree with what others have read in the English version (which I do not have), which is to limit the gasoline content to 30% for continuous cold winter driving (50% for kerosene). In the case of the inadvertent situation described by the originator of the post, the engine won't run long enough at the higher dilution numbers to cause a real problem as it will never be 100% gasoline and once the gasoline concentration gets high enough, the engine output drops to the point where it cannot produce any net power, not even enough to idle.

leathermang · #10 12-15-2009, 11:59 AM

I am sure glad JimSmith already answered because I hate to be the only one saying that kind of thing when the crowd is in the mood for hand wringing.... While gasoline is LESS oily than diesel.. it is by no means like alcohol would be ... which has no oil in it...
Now a real problem is the other way around... my father filled up his 95 Lincoln with diesel once..( it did not have a diesel engine....).

Kurt Smith · #11 12-15-2009, 12:23 PM

To help put your mind at ease and like Jim Smith said drain tank and change the filters and you will be fine. Ran a 617 for 80 plus miles until it died. Changed both fuel filters after draining the tank and that car went another 150k with no problem.

shertex · #12 12-15-2009, 12:29 PM

Thanks for the replies. The hand holding helps to reduce the hand wringing while I wait to hear from the tech.

JimSmith · #13 12-15-2009, 01:18 PM

Quote:

Originally Posted by leathermang

I am sure glad JimSmith already answered because I hate to be the only one saying that kind of thing when the crowd is in the mood for hand wringing.... While gasoline is LESS oily than diesel.. it is by no means like alcohol would be ... which has no oil in it...
Now a real problem is the other way around... my father filled up his 95 Lincoln with diesel once..( it did not have a diesel engine....).

A good friend of mine who is a Peugeot fan had this happen in the late 1960's in France to his Peugeot. An environmentally ugly situation ensued, but he was on his way in under an hour.

Jim

leathermang · #14 12-15-2009, 01:56 PM

Jim, I want you to know my solution was not just 'not ugly' but was frugal (LOL)... when he called me and said what he had cone.... I went and bought five plastic five gallon gas cans and went and siphoned out the diesel...took it home and used it in the 5600 ford Tractor.... and just filled up the Lincoln with GAS... it started and did just fine even without any other help...like changing out the fuel filter... this was away from home 30 miles so I was glad that minimum corrective actions were sufficient to get it home..

rcounts · #15 12-15-2009, 08:40 PM

I hope it works out better for you than it did for me. I was below empty and put 5 gallons in the tank from the diesel pump. The receipt even said it was diesel. The rod bearings were hammered by the time I drove 20 miles home - and there was no sign of any problem for the first 10 miles or so. Then the second 10 miles it ran progressively worse, got hot, and started knocking. Got it home, pulled the filter and it reeked of gas. I don't know what percentage of the fuel was gas, because the station never fessed up to having the wrong fuel dumped into their underground tank. But it wasted my original engine at about 202k miles.

Like I said, I hope it works out better for you than it did for me...