I've done some research on this subject but came up short on other causes ,other than water thru the intake, for this "hydrolock" to happen to a engine. Specifically I have a Dealer telling me it was diesel in the gas that caused the engine to Hydrolock and basicallly now it needs to be replaced. Now here's the deal...this is my wife's '08 Chrysler Town&Country w/ a 3.8l w/ only 26k miles, I hope someone out there can help me w/ this . We had the State of Fl inspect fuel at the last place she got gas & they found nothing wrong after testing it at the state labs. We think the Dealer is covering up a internal prob w/ their engine & just wants use to claim it on insurance instead of warranting it. Hope someone has some advice on this matter.
Thanks

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Member of Suncoast Fieros of Tampa Bay [URL=http://photobucket.com/albums/y29/sk8rfiero/My%20Fieros/

85 2M4coupe
86 SE 2M6
85 SE 2M6

Hydraulic lock is simply the condition when a volume of incompressible liquid (rather than compressible gas) exceeding the cylinder head volume somehow gets into a cylinder on the compression stroke. That liquid can be coolant (e.g. from a leaking head gasket or intake manifold gasket), oil (although that's virtually unheard of in an engine with the crankshaft below the pistons), or liquid fuel (e.g. from a badly leaking fuel injector). Hydraulic lock is also possible if a large amount of liquid (typically water or a cleaning solvent like SeaFoam) is sucked into the intake in a short period of time. I've never heard the "diesel in the gas" story before, and it doesn't pass the "reasonableness" test. The amount of fuel delivered by the fuel injector per combustion cycle is very small, certainly not enough to cause hydraulic lock in a single piston stroke, and most of any unburned fuel would leave the cylinder during the exhaust stroke anyway.

I think it's time to seek an independent and unbiased second opinion. Step one would be to take a sample of whatever liquid is in the bad cylinder and determine what it is ... coolant, oil, fuel, or pure water.

[This message has been edited by Marvin McInnis (edited 03-23-2010).]

The engine is torn down at the dealership already. I do have a sample of fuel from them in a water bottle, but thats it. I don't know where to take the sample to have any test done though.

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Member of Suncoast Fieros of Tampa Bay [URL=http://photobucket.com/albums/y29/sk8rfiero/My%20Fieros/

85 2M4coupe
86 SE 2M6
85 SE 2M6

I agree with marvin, you need to contact Chrysler direct and tell them the story you are getting from the dealer. sounds to me like a scam if it was diesel the car would not run long enough to hydro lock. i've only seen water in the cylinder cause a hydro lock and that means most of the time a bad headgasket that should be covered under the factory warranty. is there another dealer that you could take the car to to get them to look at it for you?

Hope you get some help on this
Ant

hydraulic lock, eh?
from diesel? thats odd.

anyways - if thats the ONLY problem - disconnect the fuel line, turn fuel pump on, and clear the fuel tank. then remove the spark plugs & vacuum/suck out whavever didnt leak past the rings. change the oil, being what did get past the rings is down there now. put in a few gallons of known good gas.

you now have a car with good gas & clear cyls - and if hydraulic lock, caused by diesel was the problem - it is not now.

This is a complete BS story, I can't believe they would even try to get you to believe something this ridiculous. This vehicle is still under the manufacturers warranty, replacing it should cost you nothing. If they are trying to pass the cost on to you then you are getting jerked around, tell them you want to meet with the corporate warranty claims guy, and that you are contacting the BBB about this. You might even call a law firm and ask them some questions, for a few hundred bucks I'm sure they would write a nasty letter to the dealer and Chrysler, that should get them off this quick. Chrysler is broke, they will try to save money any way they can, it's been this way for years, I dealt with it back in 2001 when our 3 year old Cherokee blew up, it had 60K on it and was out of warranty so they would do nothing for me (3 year, 36K warranty). I went back and forth with their corporate reps, I was astonished that they acted like this was not abnormal to happen. In this case the dealer was trying to help me but there was nothing they could do, I wound up towing it off thier lot to a shop where I had it rebuilt. After tearing it down we found all 6 cylinders were scarred in 2 places 180 degrees across from each other in line with the crank which means missing or incomplete thrust bearing assembly from the factory in my opinion. Anyway, I've ranted enough.

The bigger lesson here is never buy another Chrysler product, like someone told me at the time, there's a reason they've always been #3.

That is just an outright lie. Even if the tank were filled with diesel, it would not hydro lock the engine. it wouldn't run either. the amount of fuel injected even if pure diesel is not anywhere near sufficient to hydro lock a cylinder.
Most typically on a running motor, when shut down, it is the head gasket that leaks and fills a cylinder. or a crack to the water jacket. or pouring a cup of fluid down the intake.
The ONLY possible way you could fuel hydro lock a car would be if an injector completely blew out it's core and the fuel were gushing into one cylinder filling it with a liquid which is not compressible. that could be gas or whatever is in the fuel line.
They are feeding you a line of crap.

For this to happen there would have to be an
enormous amount of unburned fuel. Problem is, it should go out the tail pipes, and even if it didn't, if there was THAT much unburned fuel the car wouldn't run

You say that the engine is currently "torn down" at the dealership. Is one piston top clean ... as in a lot cleaner than the others? That's the classic signature of a coolant leak into a single cylinder; the water in the coolant "steam cleans" the piston top and the corresponding combustion chamber surface of the head. On the other hand, if all the piston tops are clean, and equally clean or nearly so, that implies that liquid water is somehow getting into the intake manifold.

If the Chrysler zone maintenance manager doesn't offer any warranty relief, you need to find find a mechanic you can trust who will go over to the dealership, inspect the engine for you, and provide you with an independent and unbiased evaluation. You will have to pay him/her for this, but it will probably be worth it. You need good information before proceeding further, and I don't think you're getting it from the dealership.

[This message has been edited by Marvin McInnis (edited 03-23-2010).]

Thank you to all that replied. Tomorrows another day and we'll be going to the dealership to see what happens.

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Member of Suncoast Fieros of Tampa Bay [URL=http://photobucket.com/albums/y29/sk8rfiero/My%20Fieros/

85 2M4coupe
86 SE 2M6
85 SE 2M6

I do agree with Marvin. I'm not sure what they are trying to do but the story doesn't make sense.

Ya I agree w everyone else, ask to take pics of the engine internal parts after all its your property they cant say no

Just a thought because it happend to a buddy's SRT4. If you went through any big puddels with an aftermarket intake system such as a ram air or cold air you could have pulled in water through your intake. Also mabey even through the stock intake with the vent being right over the filter.

I got my mower to hydro lock with fuel. I took the plug and and filled the cylinder with gasoline. I couldnt crank it over till I took the plug back out and drained it I was just trying to clean the upper cylinder and rings since it had been setting a long time. So my take is you cant get hydro lock unless you intentionally pour cups of fuel in the cylinder.

Technically it could have hydro locked if the diesel and gas mix entered the combustion chamber, the gas would burn and the diesel partially or not at all burned would leave liquid in the chamber, it wouldn’t take too many revolutions before you had enough liquid to “hydro lock” the engine. Bend a rod break a piston and so on....

Unlikely but very possible.

2 cents

quote Originally posted by Scoobysruvenge: Technically it could have hydro locked if the diesel and gas mix entered the combustion chamber, the gas would burn and the diesel partially or not at all burned would leave liquid in the chamber, it wouldn’t take too many revolutions before you had enough liquid to “hydro lock” the engine. Bend a rod break a piston and so on.... Unlikely but very possible. 2 cents

add to that, the small amount left behind may wet the plug, and prevent any further sparking

Scooby, the liquid can't collect in the cylinders. If fluid could build up cylinders we would have a hydrolocked Fiero every time our ignition control modules went out. If it was even possible to hydrolock a engine with fuel there would have to be something wrong with the fuel delivery system that is making it pour a massive amount of fuel into the engine vary quickly.

quote Originally posted by Scoobysruvenge: Technically it could have hydro locked if the diesel and gas mix entered the combustion chamber, the gas would burn and the diesel partially or not at all burned would leave liquid in the chamber, it wouldn’t take too many revolutions before you had enough liquid to “hydro lock” the engine. Bend a rod break a piston and so on.... Unlikely but very possible. 2 cents

I've always thought that hydro lock would only happen if the fluid came in quickly (or filled slowly while the engine was not running then not start) because if it just came in a squirt at a time it would be blown out the exhaust. It only locks if there is enough liquid in the cylinder on the compression stroke. It doesn't seem to me like it could ever accumulate enough fuel to hydro lock from the injector. Even without spark it would just throw it out the exhaust. Sure the cylinder would get wet but not to the point it would lock.

If this were true water from a blown head gasket would simply be pushed out the exhaust, but that doesn’t happen… What does happens is called hydro lock.

A dish piston would possibility exacerbate this as well.

Penny for my thoughts….

if it were diesel in the fuel, the normal combustion flame would burn it. the car would also smoke like a banshee, as the burn would be incomplete, but it would all be vaporized and driven out on the exhaust cycle. If there was so much diesel that it could not ignite the car would not run, and then it might load up enough, but the normal exhaust stroke would clear most of it, so again I can;t see that happening.
As was pointed out, it is not easy to hydro lock a motor. You need to have quite a bit of liquid in a cylinder to cause it, and that is very hard to do with a running motor. This is not a boat or a modified car, it is a basic minivan with a stock intake system, to suck in that amount of water would require almost submerging the car, and I think someone would have noticed that .
In all honesty I have never even heard of a normal car engine hydrolocking while running. Most times it occurs after the car has sat for a while, and the cylinder fills with coolant from a crack or bad gasket. Even then, it has to be a cylinder on the compression stroke, as with either valve open there is an escape route for the liquid.

One part that the original poster left out is how did this first present the problem? was it running and stopped dead? went to start it and it did a half crank and stopped? wouldn't crank at all? That would be a big help in finding the root cause....

taking the plug out will clear a hydro lock. Trying to start a engine with a locked piston may not hurt it, but if it trys to start before the piston stops it, you can bend/brake stuff. any body that has their **** together would pull all the plugs and clear it out, before going any farther. They are hidding / covering some thing up. But how did you find it was locked up? taking the engine down would be to hide bad head gasket/ head/ block/ intake or piss poor work on the part of the dealership people.
Fix it, get rid of it, trade it in on something, any thing not a mopar. If the wife just has to have a mopar minivan, trade her in too!

If you can print all this out, take it with you!

and no, I don't want the van or the wife, I have 2 wifes and a GF, I have enuff for now, thank you!

Not much to add here at this point, I will agree with most other posts here in that your dealer is feeding you some BS..

I am a licenced mechanic at a chevy dealer here in alberta, and specialize in fuel delivery/ignition controls and computer controls etc.. I have dealt with quite a few vehicles brought in after someone accidentally filled a gasoline vehicle partially with deisel. I have never, read NOT ONCE, encountered a situation where deisel/gasoline mix caused hydrolock, or permanent damage to the engine. As has been stated already, either theres way too much deisel in the fuel and it wont run at all, you will see fouled plugs and often the exhaust contains alot of liquid fuel, but it cant inject enough on one intake stroke to hydro lock the engine, it fails to light, and almost all of it gets pushed out the exhaust valve... In less severe cases, the engine will run, very poorly but will continue to run and smoke, make some strange noises but like I said, nothing permanantly damaged. Drain the fuel tank, flush the fuel lines and fuel rails, possibly clean the injectors, refill with good clean fresh gasoline, and your back to the races.

What I would like to know, is how this all started.. Did you one morning come out and try to start the vehicle and it just would not start and then tow to the dealer? Did it stall while you were driving? How was it running up till the point it did not start or stall?

I will echo the call for a second and unbiased opinion by a professional, at your expence. If you have to hire someone and have them go to the dealership and inspect the engine in their shop then do it.

Other than driving through a big puddle and injesting a bunch of water through the intake while it was running, there is very little that could cause a hydrolock situation that would not be covered by warranty..

Please do keep us up to date on what goes on. Being a mechanic at a dealer I really hate to hear when someone goes through this type of problem, and I very much hope that either the dealer will smarten up and do things right for you.

Best regards,
- Jay

[This message has been edited by edmjay (edited 03-24-2010).]

You can’t have it both ways…

“the normal combustion flame would burn it”

And

“the burn would be incomplete”

I think your second statement is more accurate… Diesel burns much slower than gas and in my purely amature opinion would leave something left over in liquid form…
Water is also more common in diesel fuel…

“and then it might load up”

Loading up would mean there is raw fuel in the combustion chamber (liquid) which is heavier than a vapor that exits from the exhaust.

As for the smoke… that is a given…

As far a hydro lock being real… take a look at the rod that came out of my 3.1 TGP V6…



Blown head gasket

Hydro lock is real…

My guess is that the tank was probably only partially filled with diesel and the rest gas…

Exxon has some green diesel pump handles and Amoco has almost the identical green boot on their premium gas handle.

My wife topped off the tank one day and did this very thing… When she got home she said the car was running rough… Took me two days to figure out what was wrong…

Now you got my 2 bits… all I have left…

Yes hydro lock is very real, but can not be caused by diesel in the fuel.. lets make sure thats clear. The last post could be misunderstood..
Stated blown headgasket caused the bent rod, am I to assume the fueling from the deisel pump was a separate incident or are you saying that since the vehicle was using a diesel/gas mixture, it caused it to hydrolock?

Sorry, but I just want to make sure were clear on that part for everyones benefit..

When I dropped off my truck at the local dealership a few months ago, the Jeep that was on the next lift over was towed in because the woman who owned it pumped diesel into the tank and hydrolocked the engine. The mechanic thought it was pretty funny and said it was slightly common for women who pump gas for basically the first time or so and have no idea what the "green pump" means! So I think it's entirely possible, but I dunno.

I always thought the diesel pump nozzles were larger than standard fuel nozzles, so that wouldnt happen?

I make no claims of being an expert on this subject… but enough of any liquid in the cylinder water, diesel, gas, maple syrup… you name it will cause a hydro lock.

The poster here posed the question is it possible and my answer is still yes… it is possible.

quote Originally posted by Scoobysruvenge: If this were true water from a blown head gasket would simply be pushed out the exhaust, but that doesn’t happen… What does happens is called hydro lock. A dish piston would possibility exacerbate this as well. Penny for my thoughts….

No the water from a blown head gasket enters the cylinder in large amounts quickly (or seeps in while the engine is off. The point is there is a large amount of liquid in the cylinder on the compression stroke when the valves are closed.) then on the compression stroke it locks things up. My point was that if the source was the injector the small amounts of fluid would be pushed out on the strokes that the valves are open and never accumulate enough to lock the piston.

quote Originally posted by Pyrthian: I always thought the diesel pump nozzles were larger than standard fuel nozzles ...

"You can make something fool proof, but you can't make it damn-fool proof!" ~ Larry Maisel

I was avoiding saying this, but if a dealer mechanic said it, it is a lie. they are all useless. certified or not. (ceritfied? by who????you took a test ??) I will stand by that statement, as in the hundreds of dealer mechanics and people who have had them work on their cars, all I can say is they shouldn't even work on a bicycle. if a dealer says it, they are lying to cover their butts.
sorry to offend those here, but a dealer mechanic is someone who could not cut it in a real service business. Sorry, face that truth. if you were that good you could make 3x the money with your own shop. if you quote a certification, you are a bs artist, relying on best quessing on multiple choice tests.
That is why the best advice here was an independent reliable mechanic, he is the guy who fixes it, a dealer mechanic is told what to do by the service manager.
and in all honesty, I am not really sorry for offending any dealer mechanic. I've dealt with them way too much thru all model lines to even have a remote sense of guilt.

I've had Hydro lock and it was just plain gas. I had a gas leak and it hydro'd piston #6. Shot flames all over the fire wall.

It doesn't take diesel to do it, it just requires an engine fault that spits too much fuel, or a combination of fuel and anti-freeze into the cylinder. That engine has a mechanical fault. I wouldn't let them try to duck the warranty on this one.

Arn

quote Originally posted by tjm4fun: I was avoiding saying this, but if a dealer mechanic said it, it is a lie. they are all useless. certified or not. (ceritfied? by who????you took a test ??) I will stand by that statement, as in the hundreds of dealer mechanics and people who have had them work on their cars, all I can say is they shouldn't even work on a bicycle. if a dealer says it, they are lying to cover their butts. sorry to offend those here, but a dealer mechanic is someone who could not cut it in a real service business. Sorry, face that truth. if you were that good you could make 3x the money with your own shop. if you quote a certification, you are a bs artist, relying on best quessing on multiple choice tests. That is why the best advice here was an independent reliable mechanic, he is the guy who fixes it, a dealer mechanic is told what to do by the service manager. and in all honesty, I am not really sorry for offending any dealer mechanic. I've dealt with them way too much thru all model lines to even have a remote sense of guilt.

I am not sure if you are speaking of the dealer whom the original poster dealt with or my previous post on this subject.

As far as certification, things are different here in Canada than in the states. Here we are certified by a provincially regulated apprenticeship board, much higher level of training than down south. 2 year program taught at accredited technical colleges. Yes I took tests, many.. some multiple choice, some with written answers to determine ones understanding of the technology and also many practical hands on evaluations. Certified by the Government of Alberta and licensed as an automotive repair technition.

Perhaps my income would be greater if I owned my own shop, or worked at a private repair facility, however I decided that I would stay in the dealership world so that I could specialize in GM vehicles and their repair, and therefore having a greater understanding of the newest vehicles on the road.

I find your opinion very narrowminded, and likely based on your own personal experience, which hopefully is not what everyone has to go through. There certainly are some bad mechanics out there, and they work at dealers, private shops, there own shops and their own backyards. There are also some very good mechanics out there, and you will also find them all working at any of those types of facilities.

No matter if it was intended or not, I took offence to your post and your generalization of dealership mechanics. I work very hard to serve my dealerships customers to the best of my abilities, day in and day out. I understand some people have bad luck when it comes to their experience with dealers, but rest assured this happens at service centers other then dealers and to just outright say dealership mechanics are 'bs artists', 'useless' does not sit well with me.

- Jay

[This message has been edited by edmjay (edited 03-25-2010).]

quote Originally posted by tjm4fun: I was avoiding saying this, but if a dealer mechanic said it, it is a lie. they are all useless. certified or not. (ceritfied? by who????you took a test ??) I will stand by that statement, as in the hundreds of dealer mechanics and people who have had them work on their cars, all I can say is they shouldn't even work on a bicycle. if a dealer says it, they are lying to cover their butts. sorry to offend those here, but a dealer mechanic is someone who could not cut it in a real service business. Sorry, face that truth. if you were that good you could make 3x the money with your own shop. if you quote a certification, you are a bs artist, relying on best quessing on multiple choice tests. That is why the best advice here was an independent reliable mechanic, he is the guy who fixes it, a dealer mechanic is told what to do by the service manager. and in all honesty, I am not really sorry for offending any dealer mechanic. I've dealt with them way too much thru all model lines to even have a remote sense of guilt.

strongly disagree... i have dealt with some very honest dealer mech's. there are a few good ones out there, not many but some.

If the diesel caused the car the quit running and someone continued to crank the engine over… it would dump raw fuel on top of the piston and with the tight valve to piston tolerances new automobiles run it wouldn’t take muck to hydro lock it.

quote Originally posted by Scoobysruvenge: If the diesel caused the car the quit running and someone continued to crank the engine over… it would dump raw fuel on top of the piston and with the tight valve to piston tolerances new automobiles run it wouldn’t take muck to hydro lock it.

This, and much of what you have posted elsewhere in this thread, tells me that you have no idea what you're talking about. Valve-to-piston clearance has nothing to do with it.

Hydraulic lock will occur any time the volume of incompressible fluid in the cylinder, on a compression stroke, exceeds the volume of the combustion chamber at TDC. For a 2.8 V6, that would mean about 50 cc (~1.5 fluid ounces) of liquid in the cylinder on a single compression stroke. Substantially less liquid than that, and some of it will simply be pushed out of the cylinder on the next exhaust stroke.

Is is still possible? Yes. Is it very likely? No. Analyzing a fuel sample taken from the tank would certainly establish whether diesel fuel contamination is even present or not. A simple blotting paper test, as is regularly used to test aviation gasoline for the presence of jet fuel, would be a sufficient first test.

[This message has been edited by Marvin McInnis (edited 03-26-2010).]

Marvin,

Look back at the thread… This is a 2008 dodge engine… not a 2.8

The tighter piston to valve clearance definitely apply to hydro lock.

The tighter clearances place the piston higher in the combustion chamber… most new engines have valve reliefs cut into the piston in combination with a dished piston.

My 3.5 sets .020 above the deck not in the hole.

This puts the piston further into the combustion chamber leaving less room.

Marvin,

Look back at the thread… This is a 2008 dodge engine… not a 2.8

The tighter piston to valve clearance definitely apply to hydro lock.

The tighter clearances place the piston higher in the combustion chamber… most new engines have valve reliefs cut into the piston in combination with a dished piston.

My 3.5 sets .020 above the deck not in the hole.

This puts the piston further into the combustion chamber leaving less room.

You will not convince me that the all or even most of the liquid is pushed out the exhaust, and especially on a motor that is cranked without the engine starting continually.

The liquid would have to go strait up and besides I have seen raw fuel on the top of a piston too many times.

quote Originally posted by sk8rfiero: I've done some research on this subject but came up short on other causes ,other than water thru the intake, for this "hydrolock" to happen to a engine. Specifically I have a Dealer telling me it was diesel in the gas that caused the engine to Hydrolock and basicallly now it needs to be replaced. Now here's the deal...this is my wife's '08 Chrysler Town&Country w/ a 3.8l w/ only 26k miles, I hope someone out there can help me w/ this . We had the State of Fl inspect fuel at the last place she got gas & they found nothing wrong after testing it at the state labs. We think the Dealer is covering up a internal prob w/ their engine & just wants use to claim it on insurance instead of warranting it. Hope someone has some advice on this matter. Thanks

There's more than enough mileage on it to suggest the driver knows what he/she is doing at the pump and it is highly unlikely that diesel fuel was placed in the tank by accident as evidenced by the test results and the fact that even after picking up the green handle you still have to unwittingly select diesel fuel to pump it.

Have you had any service performed on the vehicle like a 3 stage fuel injection cleaning? A GM 3500 V6 mini van was hydrolocked from that at least I suspected. It was running when it arrived and had to be towed out before the cleaning process was completed. I believe in-attention to the process resulted in an engine stall and then restart attempt after fluid had unknowingly puddled in the intake while it was off as I've observed a direct feed through a vacuum fitting on the intake as part of the proceedure which involves a canister of fluid hanging above the engine like an IV. There are some great mechanics out there, but I tend to see some of the worst. The ones that take a shot-gun approach to repair really bother me. They recommend replacement of every sensor associated with a particular engine code instead of actually diagnosing. Reminds me of the MAF sensor I bought because a GM certified Tech pulled a code (same one I did) and said the MAF was bad. The MAF was fine, the relay was bad, had he done what I paid the dealership to do Diagnose I would have spent ~$50 total instead of over $250 since I couldn't return the used electrical part.

You need to have them prove to you the engine was actually hydrolocked and then explain what caused it. ASE certification means nothing to me, I can coach my mom enough to pass several of those tests. It's more a selling tool than it is a measure of competance in my oppinion.

[This message has been edited by Joseph Upson (edited 03-26-2010).]

Let’s hear from the poster…

Did you have the fuel in the car tested SK8R???

Did it have diesel in it ???

Did the last place your wife got gas sell diesel???

Is a rod bent, or a piston broken???

What is exactly wrong with the engine and how exactly did the dealer determine what was wrong and the cause of it???

Did they disassemble the engine and did they put it back together???

quote Originally posted by Scoobysruvenge: This is a 2008 dodge engine… not a 2.8

OK ... in a Chrysler 3.8 V6 it will take about 70 cc (~2.3 fluid ounces) of liquid in a cylinder on the compression stroke to cause hydraulic lock. Everything else I said remains unchanged.

Here are some other possibilities in which the diesel could have caused the problem…

The diesel could have caused detonation just from the low octane of the fuel, once detonation occurs… head gaskets are usually the first thing to go… water enters quickly and you have hydro lock…

A small amount of fuel builds up in the chamber… not enough to hydro lock the engine, but this small amount of incompressible fuel drives the compression up to let’s say 11:1 (this would require very little liquid to achieve)

Now the engine detonates again for lack of octane at the 11:1 compression… causes detonation, the head gasket blows, water enters quickly and you have hydro lock…