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2007 JK Engine Destroyed by Diesel

13K views 71 replies 26 participants last post by  MoabCarl 
#1 · (Edited)
[Sorry for the long tale but it's a good read]

My 2007 JK has about 120,000 miles on it. Just before Christmas I ran out of gas at night (my daughters, both home from college, had been joyriding it around town getting LOTS of attention earlier in the day) and AAA came with my two free gallons of gas. Unfortunately, the moron did not realize that the two gallons he put into my tank were diesel, not regular unleaded. Neither did I.

Now the story gets interesting.

The vehicle started, but 1/4 mile away it died. The same AAA contractor towed me to my mechanic. The next day I heard that my fuel pump had failed. The following day I heard that the pump had been replaced, and that the fuel system was basically pure diesel, which had caused the fuel pump to fail. My mechanic had tried to start and drive the vehicle a number of times after replacing the fuel pump, and it didn't start, and that's when he decided to check the fuel itself and detected the diesel. Meaning, diesel ran through the new fuel pump as well. Then he flushed the fuel system, put in regular unleaded, and the car seemed to work OK.

Fine. I paid the mechanic and filed a claim with AAA for about $1,000.

I took the jeep on a run for about 120 miles with no performance issues a couple days later.

A couple days after that, I left on another day trip but my engine began making a very metallic knocking going up a grade. I called AAA again and got towed 75 miles to my special jeep mechanic because I wondered if this was still an aftershock from the diesel thing. A couple days later this second mechanic told me three of my rods were destroyed and that he smelled diesel fuel in the oil that he drained into the pan. How did diesel get in the lubrication system, I asked. He said that diesel won't burn in the carburetor but runs down the walls and seeps through some seal into the lube system.

Why did it take a week and over 200 miles of driving to finally damage my engine, I asked him. He said diesel has no lubrication properties, so it takes a little time (e.g., a few days and 200 miles) for the degradation in the engine to finally take hold. That's why the engine didn't fail immediately after I picked it up from the first mechanic.

But then, this specialized mechanic says that it is possible that my engine was ready to fail already, and the diesel just put it over the edge. I want to update my claim to AAA for both the fuel pump and a rebuilt engine (now a total of $8500), but the mechanic is unwilling to openly state that "diesel caused the engine failure."

So here are my questions:

1) Do 2007 JK engines (V-8, 6 cylinder) fail as early as 120,000 miles or can they be counted on to last a lot longer?

2) Was my first mechanic responsible for the engine failure, because he ran diesel through the new fuel pump and did not know about that other situation, where diesel can seep into the lube system?

3) The second mechanic said that diesel seeps into the lube system from the carburetor. Is this a high probability occurrence? How could this have happened if the fuel system had been cleaned of diesel by the first mechanic? Does it take a lot of diesel to ruin lube in the engine, or just a little?

4) How long does it take for an engine to fail after it gets some contaminant (like diesel) into the lube system? A day and a few miles? Or a week and 200 miles?

5) I do not believe in coincidences. So if the engine failed a couple hundred miles after flushing the fuel system, and the oil smelled like diesel, then the damn engine failed because of the diesel, and not because it was already on the point of failure. Is that the right conclusion?

6) Has anyone on WF lived through this experience? How did it come out?

Thanks for any and all replies.
 
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#2 ·
I think plenty of 3.8’s have failed before 120,000 miles. I doubt enough diesel was able to get into the system to cause the issue. Rods are usually destroyed because of hydro locking type situation.
 
#5 ·
Explain hydro locking in more detail, please. Can poor maintenance cause this, or is it just a matter of engine age and sheer probability?
 
#3 ·
I think that you would have a valid claim against AAA but there’s no way you’ll get $8,500 from them. At most, you can likely collect the initial $1k in repair costs and then the cost for a comparable engine with the same mileage. A new engine would be considered unjust enrichment.

The main reason I say this is because I listen to a very reputable talk show every day that deals with issues like this all the time. He takes calls from people on many topics and high mileage vehicles are very common.

I hope they can help you get back to where your Jeep was prior to this.
 
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#4 ·
I think that you would have a valid claim against AAA but there’s no way you’ll get $8,500 from them. At most, you can likely collect the initial $1k in repair costs and then the cost for a comparable engine with the same mileage. A new engine would be considered unjust enrichment.

The main reason I say this is because I listen to a very reputable talk show every day that deals with issues like this all the time. He takes calls from people on many topics and high mileage vehicles are very common.

I hope they can help you get back to where your Jeep was prior to this.

Thanks. My $7400 quote was for a rebuilt engine ($5500) plus labor. What do you think the depreciated value would be for a relatively low mileage engine if not $5500?
 
#12 · (Edited)
I have known of people who accidentally ran diesel in a gas engine. None of them ever destroyed the engine. I ain't saying it isn't possible, but it would seem to need more to the story, like excessive cranking and somehow getting fairly large amounts (respectively) of diesel fuel in the combustion chamber. As mentioned, liquids like diesel fuel (and water) don't like to compress. So it could bend rods if too much fuel that won't burn made its way into the combustion chamber. But that begs the question, how did all that diesel fuel get into the combustion chamber. The only way I could see it happening is someone using starting fluid to try to get it running with the diesel still in the fuel system. That could possibly cause enough diesel fuel to be injected into the cylinder while at the same time providing enough force to bend the rods when the diesel fuel won't compress. But I am just guessing.
Good luck with your saga.
Now is a good time to look into a small block chevy upgrade.
 
#22 ·
I ain't saying it isn't possible, but it would seem to need more to the story, like excessive cranking and somehow getting fairly large amounts (respectively) of diesel fuel in the combustion chamber.


Now is a good time to look into a small block chevy upgrade.

Well, on the first night I probably tried to crank the engine about 10 times without success. Then, after mechanic #1 installed the new fuel pump, he tried to crank it a bunch of times, let's say another 10 times. So is 20 times enough?


Also, tell me more about the small block chevy upgrade. Is this a chevy engine in my wrangler?
 
#19 ·
Over the Years I have seen and been told of a number of engines both Cars and Trucks that ran with gas in a diesel engine or diesel in a gas engine . A friends wife put gas in a new jeep (diesel) and It died after 8 miles (going home) it was fine after cleaning it and the filters out . I also seen a new diesel pickup truck go 35 miles on gas before it was found not to be diesel fuel . The dealers lube guy filled it with gas before the new owner picked it up it is still going fine years later . I do not know what happen to your wrangler but if you drove 200 miles after the diesel fuel was cleaned out you may have a problem .
 
#20 ·
It would have taken a lot of diesel in a cylinder to even begin to hydrolock. Water in the cylinders causes hydrolock when there is a lot of water in the cylinder. Water in the fuel won't do it. Generally hydrolock is caused by excessive intake of water through the air intake system as the result of submersion of the front of the vehicle in water not the fuel system.

Diesel is a fuel, just a very low ignition fuel that ignites as a result of the high compression ratio in the cylinder (generally around 22:1) while our gas engines require a spark plug and a high volatility fuel (gasoline) because of the relative low compression ratio of the engine (about 8.5 to 1 I believe).

When the diesel was added to the tank, the fuel system would not have seen pure diesel, for the tank is not really empty when the engine dies from fuel starvation.

When the diesel is sprayed into the cylinder it will mix with the air that has been sucked in, it will just not combust. On the exhaust stroke the diesel/air mixture would be expelled into the exhaust system. Now it is possible that the engine was cranked long enough to expel enough diesel/air mix into the cats to plug them. That back pressure would be enough to cause the engine to run poorly after pure gas was put in, but would it be enough to bend/break a connecting rod? I don't know.

There have been enough issues around diesel accidentally pumped into a gas tank that the opening in the fuel filler and fuel nozzle are different sizes. This difference initially came into play because of the leaded/unleaded fuel where a vehicle designed for unleaded fuel had the smaller opening as did the fuel nozzle. As leaded gas disappeared from the retail distribution system the opening and nozzle smaller size was retained while auto diesel used the larger size. Those who have operated diesel PUs and filled them up at pumps for over the highway trucks at truck stops know their nozzles are even larger (they also have tanks many times larger than the fuel tank on a car/piclup/Jeep.
 
#21 ·
It would have taken a lot of diesel in a cylinder to even begin to hydrolock. Water in the cylinders causes hydrolock when there is a lot of water in the cylinder. Water in the fuel won't do it. Generally hydrolock is caused by excessive intake of water through the air intake system as the result of submersion of the front of the vehicle in water not the fuel system.

Diesel is a fuel, just a very low ignition fuel that ignites as a result of the high compression ratio in the cylinder (generally around 22:1) while our gas engines require a spark plug and a high volatility fuel (gasoline) because of the relative low compression ratio of the engine (about 8.5 to 1 I believe).

When the diesel was added to the tank, the fuel system would not have seen pure diesel, for the tank is not really empty when the engine dies from fuel starvation.

When the diesel is sprayed into the cylinder it will mix with the air that has been sucked in, it will just not combust. On the exhaust stroke the diesel/air mixture would be expelled into the exhaust system. Now it is possible that the engine was cranked long enough to expel enough diesel/air mix into the cats to plug them. That back pressure would be enough to cause the engine to run poorly after pure gas was put in, but would it be enough to bend/break a connecting rod? I don't know.

There have been enough issues around diesel accidentally pumped into a gas tank that the opening in the fuel filler and fuel nozzle are different sizes. This difference initially came into play because of the leaded/unleaded fuel where a vehicle designed for unleaded fuel had the smaller opening as did the fuel nozzle. As leaded gas disappeared from the retail distribution system the opening and nozzle smaller size was retained while auto diesel used the larger size. Those who have operated diesel PUs and filled them up at pumps for over the highway trucks at truck stops know their nozzles are even larger (they also have tanks many times larger than the fuel tank on a car/piclup/Jeep.

OK, you appear to know the mechanism how this might work. Could you write up here a scenario, even if it's low probability, how the diesel would have ruined both (1) the fuel pump and (2) three rods, also accounting for the lapsed time of a few days and 200 miles? Also comment on whether the first mechanic is responsible for the engine failure, because he did not flush the lubrication system or something.


I've found sources that say losing the engine is low probability but my situation appears to have been that 5% probability situation.
 
#24 ·
The diesel fuel would not ruin the fuel pump.
If the engine cranked over freely, it was not hydro-locked.
In all probability, the diesel did not cause engine failure.

We have had it happen both ways.
Employee pumped a duramax full of gas, it ran about 6 miles and quit. We drained the tanks(had2), and filter. Filled filter with fuel, filled tank with fuel, and after several fuel filter fillings, started up and ran like a top.

Employee, filler 2500 Chevy service truck with fuel
Died about 3 miles from shop.
Drained tank, filled with gas, got it running, no issues what so ever.

Both instances happened 3 years ago, and vehicles are still running fine.
Also, diesel fuel will not clog your injectors.
 
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#27 ·
This can’t have anything to do with Hydrolock. According to the OP, the engine ran for hundreds of miles on multiple trips after the diesel was removed. Rule that out.

All the conversation about destroyed rods assumes they were bent or actually broken. I’ll offer there is no chance a motor actually physically destroyed 3 rods and continued running with what was described as just a metallic knocking.

Something doesn’t add up. Check with the mechanic who said “rods were destroyed”. He will likely correct you and state it is rod (bearings) either piston, crank or both that were damaged.

Enough diesel fuel in the oil could cause bearing failure over many miles. It would most definitely make a metallic knocking as the bearing surface is wiped and essentially running metal to metal. If you clarify this point, you can likely go a long way in placing the blame on the introduction of diesel into your gasoline engine.

Diesel is likely the culprit, not coincidence.
 
#33 ·
You are right! My mechanic #2 said that the rod bearings were broken. I told him that some WF gurus said that the elapsed time and mileage before the engine failed only made sense if it was the bearings.



So .... now we have a theory that makes sense.
 
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#29 ·
My thoughts too :). I was wondering what they were doing to get "lots of attention"?
 
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#34 ·
Just Google “Diesel Fuel Dilution”. It’s really a misnomer because it’s really (oil dilution by diesel fuel).

This is very common in diesel engines and is part of ongoing ownership and maintenance. Importantly, they have the added cushion of heavy engine oils to make this manageable.

The point is, you possibly had a significant amount of diesel fuel introduced into thin 5-30 weight oil. An otherwise fine, but aging, engine doesn’t stand a chance without adequate lubrication.
 
#38 ·
It is not common in diesels.
If you have a diesel putting fuel in the crankcase, you have issues.
 
#35 ·
hopefully the mechanic saved the oil to submit to a place like blackstone labs. They could tell you exactly how the oil was affected.
 
#40 ·
Explain a little more please. 07 crankcase holds 5 quarts. You're saying that for a new engine a little bit of diesel slipping into the lube system would have no impact, but for an aged engine it would? How much diesel are we talking about?
 
#42 ·
You need to file a claim with insurance and let them handle it (assuming you have decent insurance). If they wont, maybe talk to a lawyer. The diesel caused this one way or another. Maybe on a new engine it wouldn't, maybe the 1st mechanic made it worse, maybe you made it worse by driving up a mountain. Regardless it all started because AAA made a mistake. You might be surprised what getting Insurance involved will do.
 
#43 ·
A little bit of fuel, even gasoline, is not an issue in the oil. If gas, once the engine is up to running temp, the gasoline will evaporate out. When the military was using reciprocating engine aircraft to fly to the North and South poles, they would as policy put a certain amount of gasoline in the oil sump so that the oil would move the next morning when they started the engine. After the engine was thoroughly warmed up, the gasoline would have evaporated.

In the case of diesel, it is in fact oil. Just a thinner oil. It would take a great deal of diesel in the crankcase to thin out the engine oil enough to cause damage.
 
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#44 ·
Question to those who say diesel in the motor oil simply cannot contribute to the destruction of a gasoline engine. Ask yourself, if your otherwise well running Jeep had diesel dumped in the gas tank and your Jeep suffered catastrophic engine failure 100 miles later; would you really chalk it up to incredible coincidence? No you would not.

Engines don’t simply die of old age by destroying 3 rod bearings (at the same time) without other serious contributing factors involved.

From the original post:

- “The fuel pump was replaced”. (presumably destroyed after pumping significant amounts of diesel fuel, much of which ended up in the oil pan).

- “The second mechanic smelled diesel fuel in the oil”. If the mechanic still noted the smell (after the Jeep had been driven for more than 100 miles) then you can conclude there was more than “just a little” fuel in the oil if it was still there after multiple significant drive cycles.

Fuel dilution is a fact and is precisely what you’re obviously referring to in the aircraft example. But volatile gasoline is very different than diesel fuel. Under normal circumstances dilution causes no significant issues given reasonable conditions and service intervals. It’s accounted for by auto manufacturers. But, what happens when you dilute the oil significantly, and all at once, by pumping raw diesel into the cylinders? Enough diesel to burn out a fuel pump... replace that first pump and continue pumping even more raw diesel with a second fuel pump.... Seems a little possible after all.

If you dilute 5-30 with enough diesel to effectively make it, say, 0-10 or thinner, (and this with oil that’s been in the crankcase for some time and presumably already somewhat compromised by heat and use) you no longer have an oil capable of protecting rod bearings under significant load while traveling at speed up a hill. Heat and load are, in fact, concentrated on rod bearings.

A lack of sufficient lubrication will destroy bearings. This lack of lubrication can stem from compromised oil, blocked oil passages from sludge released by the cleaning effect of diesel in the engine oil, etc., etc. The actual mode(s) of failure, including those totally unrelated to the introduction of diesel fuel are impossible to determine with the limited information... but the introduction of significant amounts of diesel (and therefore diluted oil) can certainly contribute to engine failure in an already worn engine.

And for those that need to hear it from a source that knows more about this than most of us...

Quoting Bell Performance: (but there are plenty of sources on this topic)

“If enough diesel fuel gets in the cylinder, you can hydro-lock the cylinders, resulting in a blown head gasket, cracked cylinder head or other serious problems that can lead your vehicle down the road to a quick and final death. This diesel fuel in the cylinder can also seep past the piston rings into the oil crankcase, diluting the lubricating oil. This can damage all internal engine lubricated parts resulting in major engine failure from rapid wear”.

I do not know for a fact what occurred here and will freely admit this. But maybe best to consider all the contributing factors before stating something simply cannot happen.
 
#46 ·
If you dilute 5-30 with enough diesel to effectively make it, say, 0-10 or thinner, (and this with oil that’s been in the crankcase for some time and presumably already somewhat compromised by heat and use) you no longer have an oil capable of protecting rod bearings under significant load while traveling at speed up a hill. Heat and load are, in fact, concentrated on rod bearings.
It would be impossible for the diesel to dilute the crankcase that much for several reasons - the first is that the other name for diesel is #1 Fuel Oil. Yes it is thin, but not that thin. In fact, in extreme cold weather, a diesel can be hard to start because the fuel is so thick it is hard to move.

The reason diesel is cheaper in the summer is that it has no competition in the oil market. In the winter, a lot of homes are heated with #1 Fuel Oil, so there is a lot more demand. The difference between diesel and #1 Fuel Oil? There are additives to #1 Fuel Oil to make it saleable as diesel, the same as there are additives to gasoline for sale at the pump. You can burn diesel in your furnace (if you have an oil fired furnace) it would just be more expensive but would probably burn cleaner.

Secondly, if you have 4 quarts of crankcase oil and pump as much as 1 quart of diesel into it, you have only diluted the oil by 20% to maybe #$4. Secondly, there is the fact that he drove the Jeep some 200 miles after the incident.

Thirdly, if the mechanic "smelled diesel in the oil" did no one think of changing the oil?

A lack of sufficient lubrication will destroy bearings. This lack of lubrication can stem from compromised oil, blocked oil passages from sludge released by the cleaning effect of diesel in the engine oil, etc., etc. The actual mode(s) of failure, including those totally unrelated to the introduction of diesel fuel are impossible to determine with the limited information... but the introduction of significant amounts of diesel (and therefore diluted oil) can certainly contribute to engine failure in an already worn engine.

And for those that need to hear it from a source that knows more about this than most of us...

Quoting Bell Performance: (but there are plenty of sources on this topic)

“If enough diesel fuel gets in the cylinder, you can hydro-lock the cylinders, resulting in a blown head gasket, cracked cylinder head or other serious problems that can lead your vehicle down the road to a quick and final death. This diesel fuel in the cylinder can also seep past the piston rings into the oil crankcase, diluting the lubricating oil. This can damage all internal engine lubricated parts resulting in major engine failure from rapid wear”.

I do not know for a fact what occurred here and will freely admit this. But maybe best to consider all the contributing factors before stating something simply cannot happen.
Well, we know that hydrolocking of the cylinders did not occur - if it had it would have stopped the engine right then, not bend and break the rods 200 miles later. It would have occurred as they were using the starter when trying to start the engine.

If you had enough diesel to hydrolock the engine it would not start at all. Since it started and ran for 200 miles what diesel was in the cylinders would have obviously burned off.

As to cleaning out the accumulated grit and grime in the oil pan, that is feasible, but the same can be said of replacing the regular oil after an awful lot of miles with high detergent oil. That would have required an awful lot more than 200 miles.

Do I think AAA has some responsibility in this - yes. Do I think the OP has a case against them - tenuous at best. The key fact is the 200 miles the Jeep was driven after the incident. That will be hard to get around.
 
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#45 ·
A possibility, some of this already mentioned:
In your gas engine, when gas is in it, the gas burns. The diesel won’t, so it wets down the cylinder walls, pistons, n rings. With 120k on engine, piston/ring to cylinder clearance is larger than new engine (from normal wear), which allows for some “blow by”, normally harmless combustion gases, vented thru crankcase ventilation, although it dirties oil as well. Since diesel didn’t burn, it saturates possibly pools, and leaks past the pistons/rings into the oil, thereby diluting the oil, losing the oils lubriciity,which “washes out” the bearings, cylinder walls, any other oil lubricated parts. This causes rapid premature wear, and can cause catastrophic failure, as in your engine with rod bearings out. I imagine there is more premature wear in other engine areas as well. So, hopefully the oil was saved and can be tested for diesel contamination, although some diesel level may dissipate over time. The question is, was there enough diesel fuel in the oil, to thin the oil out enough to ruin engine in 200 miles.
Definitely possible, and a direct result from the diesel being added in fuel tank.
Is it probable? Depends on diesel/oil ratio.
However, I’ve seen stranger things happen. It does remain possible.
Could it have been from something else? Yes, of course. However, if the diesel was not the main or direct cause, it may have been a contributing factor- to what extent, or percentage of fault? Probably have to be determined by a qualified engine rebuilder, that can examine, in detail, and determine cause.
May have to contact AAA, and find out WHO they want to look at the engine/vehicle in your area.
Document all dates, times, mileage, etc while it’s fresh in your mind.
Hope this helps, best of luck, let us know how it goes, keep posting on this.
What a dilemma.
 
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