turbo charger the mechanic said

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Re: turbo charger the mechanic said

Reply #25 – May 23, 2011, 09:08:41 pm

To the list of bad diesel engines, I would add the Volkswagen six cylinder engine that Volvo used circa 1980. The engine might have been OK, but not the way Volvo put it in their sedan. It was underpowered, smoky and had a terrible air intake arrangement.

One day many years ago we had a significant, but not unusual rainstorm in Houston. Daughter drove the Volvo, Bride drove the MB 300D. Each went through curb deep water. The Volvo sucked water from the low air intake and bent rods. The MB sustained no damage. The Volvo engine was used up at 140K miles even though it had a rebuild after the water incident. The MB was still doing fine at 230K when we disposed of the car.

OEM components for Foretravel have generally been high quality. Folk seem to be having good experience with 20 year old vehicles if the maintenance has been reasonable.

This forum includes participants with knowledge and good experience with all the diesel engines Foretravel has installed. From what I have read in this discussion, it sounds like Tommy may get some good benefit from that knowledge. We hope the problem is as simple as a loose wire on the fuel switch solenoid.

Re: turbo charger the mechanic said

Reply #26 – May 24, 2011, 07:26:16 am

Thanks folks for posting where the fuel cutoff solenoid is on a Cummins. Filed for reference.

I remember reading about runaway DDs. One brave veteran mechanic stuffed his jacket into the air intake - it worked that time. Another time he just ran for cover and the engine grenaded. Seems the most common cause was leaking blower seals.

I noted the air intake on my 91 U225 - it appears that covering the grill would suffocate the engine (?). Going to fabricate something and test it, just in case.

Steve

Re: turbo charger the mechanic said

Reply #27 – May 24, 2011, 11:00:43 am

JD,

You must have had a 240. I remember that engine well. It was made at VW's engine factory up north in Germany and trucked into Sweden. Used in VW vans about the size of a Ford Econoline. Non-turbo and anemic. Had a big VW as part of the engine casting. A Volvo dealer told me that they (Volvo) made so many of the engines for VW vans that they cast VW in the block at the Swedish factory. One more reason to count your fingers after shaking hands at a dealership. Volvo did not have the cash to make new engines so they outsourced. They also went to France for the Renault V6 of DeLoren fame. It was 1000x worse than the VW diesel. Beautiful to look at from the outside, sort of like a Formula 1 engine but cams went quickly, bad head gaskets and even worse, you had to partially remove the engine to get the heads off. No clearance on the body.

These runaway engines are ultra high mileage, several times what a Foretravel would accumulate in it's life. Nice to read about things that have gone wrong and to file away in the back of our minds just in case. Some of us have tinkered with mechanics since we were kids but others have gone different directions with different skills, skills that are just as important in life. Sort of like flying in an airliner. Interesting to read about incidents but the possibility of it happening to us is very remote. Hate to ruin a RV (or flying) experience with the notion that something major is just around the corner. What some of us can laugh off, fill others with dread. The forum is great for solving the little things that crop up, the dip stick tube than breaks off, how to repair that roof crack, etc. and preps us for that one in a million situation that could pop up. Better to worry about our home town bank failing.

Pierce & Gaylie
'93 U300/36

Re: turbo charger the mechanic said

Reply #28 – May 25, 2011, 12:36:49 am

Got back home monday evening after good sam's towed me to tifton to a shop called ten speed truck shop, a pilot truck stop. My wife's uncle has an auto electric shop in that town and when she called him he said oh no, you better watch them, but they worked me in, even tho my motorhome arrived late, about 1:00 oclock pm. They tried to start it after I showed them where the fuel shutoff was which they already new, but it would only click. they pulled starter out and it was ground up by the flywheel, thank goodness the flywheel is much harder and did not get damaged. I told them I would take starter and went and got one from wife's uncle for 180 dollars. They put starter on and it would not start, just click, so they kept checking and found a loose ground. Since they were working on it in between lots of trucks I thought they did a good job. I learned a lot that night. You can't choke that diesel down by cutting air supply when it's getting fuel and fire, you have to take engine battery loose or pull the plug on injector pump, and I learned that thanks to the people on this forum. Oh the guy who came and quoted me all the bad news he thought was wrong with turbo was wrong, but he was a nice guy and he came out because his friend the sheriff called him and I respect him even tho he was wrong.

Thanks tommy t.

Re: turbo charger the mechanic said

Reply #29 – May 25, 2011, 12:40:17 am

There's some good old boys down there in Tifton...

Re: turbo charger the mechanic said

Reply #30 – May 25, 2011, 07:54:00 am

Tommy,

I don't understand the comment that cutting off the air supply would not stop a diesel (or any internal combustion engine for that matter)-- it will. Combustion requires fuel AND AIR (oxygen). Either without the other will not run.

And I would be very concerned about the effect on the alternator with disconnecting the battery with the engine running. A running alternator charging an open circuit generally blows the alternator diodes.

Brett

Re: turbo charger the mechanic said

Reply #31 – May 25, 2011, 08:32:20 am

Tommy, Glad you got things figured out.
I am curious though, what relationship did your bad starter have to the engine no stop condition? Did the starter somehow engage while engine was running ?
And I side with Brett, any engine can be stopped by starving it for air, maybe not easy to do but it will shut down.

Gary B

Re: turbo charger the mechanic said

Reply #32 – May 25, 2011, 09:26:33 am

Why would a diesel engine care if the battery were disconnected?

Re: turbo charger the mechanic said

Reply #33 – May 25, 2011, 09:53:32 am

Would it not be a rather simple matter to determine if a turbocharger has a blown oil seal, by removing a piece of the induction system between the turbo and the engine and check for a coating of oil? Maybe I am missing something or is this too simple? Some of the statements in this thread do not seem to be correct. We went from an engine that would not shut down to a ground up starter??? Not doubting that either did not occur. The small starter gear has a few teeth vs a great many teeth on the flywheel. The larger gear usually wins when wear and tear are involved, not that it is harder metal, IMHO.

Re: turbo charger the mechanic said

Reply #34 – May 25, 2011, 11:24:42 am

Quote from: amos.harrison – May 25, 2011, 09:26:33 am

Why would a diesel engine care if the battery were disconnected?

It would cut power to the fuel pump solenoid. Disconnecting 12 VDC from the solenoid either by turning off the key or disconnecting the battery cuts fuel supply to the engine and is how it engine IS stopped.

Were the cutoff mechanical, you are correct, disconnecting the battery would have no effect. The diesel in our boat is set up this way. When we got into a severe electrical storm offshore 3 years ago, I started the engine, knowing that a lightening strike would likely disable enough of the electrical system that starting the diesel would not be possible. And once started, it really would not care about electrical power to it. Luckily, we only had a heck of a light show for 5 hours but did not get struck.

the other Brett

Brett

Re: turbo charger the mechanic said

Reply #35 – May 25, 2011, 01:46:56 pm

Battery, alternator disconnect/failure may or may not stop a diesel depending on the fuel cutoff method. To run, many diesels have a fuel solenoid that requires 12V to STAY OPEN and supply the fuel to the injection pump. A couple examples are VW, Ford 6.9/7.3 diesel engines. If you loose 12V, the engine stops. Still others like Mercedes have a vacuum actuator on the pump to SHUT OFF the flow of diesel fuel and stop the engine. With the latter, the engine will keep running without any electrical system in the vehicle. In fact, you can start a MBZ without a battery by pulling the automatic back into first, coasting down a hill and off you go. This kind of setup always has a manual shutoff on the injection pump should the key switch fail (has a vacuum connection). Boats (like Brett has) and other mechanical (non-computer) diesels don't usually require 12V to keep running. Boats, Lucas electrical systems and a salt water environment never mix and failure happens frequently. Because of this, some may even have a hand crank option. Probably a good thing to know which system you have in your rig in case you can't shut it down or it won't start.

No engine, diesel or gasoline will run if you shut off the air. Mechanical Detroits had a spring loaded plate to block the air in case of shutdown failure. Used it several times because of corrosion of the electrical connections on the old bus.

Pierce & Gaylie
'93 U300/36

Re: turbo charger the mechanic said

Reply #36 – May 25, 2011, 09:09:52 pm

As I have learned from my race car, disconnecting the battery if the alternator is charging WILL NOT shut down anything as the alternator (if the diodes are not blown) will continue to provide 12 volts. The kill switch on all alternator powered race cars has to be checked with engine running to make sure that power is shut off to the ignition system or the electric fuel pump.

Re: turbo charger the mechanic said

Reply #37 – May 26, 2011, 01:20:16 am

Yes Brett, I am sorry, I should have said I was unsuccessful stopping that diesel of mine, I certainly don't know anything other than my experience, Also in order not to be too lengthy on my last post I ommitted part of the story, I had already disconnected the alternator wire at the isolater, and I assume from what the mechanic said the starter engaged and did not disengage and that's what kept it running. So when we finally pulled the engine batteries loose, it stopped. When I got to shop and they pulled starter off because it would not turn over, then I was just as surprised as anyone about how we went from my subject (turbo charger the mechanic said) to (ground up starter). I hate to admit what I did as for as trying to cut off air to engine but I might as well. I took filter out with it running and stuffed 2 big towels in the housing. I will not do that again. tommy t.

Re: turbo charger the mechanic said

Reply #38 – May 26, 2011, 05:06:52 am

One trick we learned in the fire service, on the old Detroit engines that were "running away" was to discharge a CARBON DIOXIDE fire extinguisher into the air intake of the engine, this displaces the Oxygen and shuts down the compression cycle. Make sure it is CO2 gas extinguisher, not Dry Chemical (Powder)....

Re: turbo charger the mechanic said

Reply #39 – May 26, 2011, 05:33:59 am

Jeez, this subject has taken on a life of wonderment's.
How would the starter become engaged ? Since it is not an automatic start system,it would appear the key was turned (Starter button pushed) to the start position and held, resulting in the ground up pinion teeth, Oh yes be glad the ring gear is tuffer than the starter gear.

In our business, we have had four cases of Delco MT-38 (I think) when engaged, the starter got hung in, this always ended up with fried starter, battery cables and batteries. Happened to both 12 and 24 volt models. Replacement with new starter is preferred to a rebuilt and better price. About $375.00 for new MT-37 for Cummins C Series, Only happens to the C Series so far, Maybe someone has the answer to that mystrey.

Have been meaning to look at the model on the coach, but just never got around to it yet.
Must be getting too old and lazy.
Cheers

Re: turbo charger the mechanic said

Reply #40 – May 26, 2011, 07:07:01 am

Tommy, We have all made errors of one kind or another. By telling us the whole story you have probably caused someone to retain information that will help out in the future. I don't think I will live long enough to make every mistake there is but I am trying.

Re: turbo charger the mechanic said

Reply #41 – May 26, 2011, 08:01:47 am

Quote from: tommy thompson – May 26, 2011, 01:20:16 am

Yes Brett, I am sorry, I should have said I was unsuccessful stopping that diesel of mine, I certainly don't know anything other than my experience, Also in order not to be too lengthy on my last post I ommitted part of the story, I had already disconnected the alternator wire at the isolater, and I assume from what the mechanic said the starter engaged and did not disengage and that's what kept it running. So when we finally pulled the engine batteries loose, it stopped. When I got to shop and they pulled starter off because it would not turn over, then I was just as surprised as anyone about how we went from my subject (turbo charger the mechanic said) to (ground up starter). I hate to admit what I did as for as trying to cut off air to engine but I might as well. I took filter out with it running and stuffed 2 big towels in the housing. I will not do that again. tommy t.

Tommy, don't feel bad about mistakes, we all make them and can help others by describing them here.

It may be because it is early in the morning but I still am not clear about what caused the problem and now I'm not even sure I know what the problem was. Did the engine keep idling for hours or was the starter engaged for hours? If the starter was running constantly, I am very surprised that the batteries didn't die or the starter burn up and lock up.

Re: turbo charger the mechanic said

Reply #42 – May 29, 2011, 01:15:16 am

Dave, I will continue and try and clear any left over questions and maybe help someone. In my first post I said I was sitting with engine running, I had started engine while in the motorhome park paradise lake 9 miles east of tifton, to reajust leveling jacks and from the seat it sounded like starter solenoid did not retract but when I ran back to engine it was just noise like an engine going bad. I went to the front and turned key off and it kept running. Kent, the ones who took off starter and handed it to me, made me think that the starter kept turning and the engine kept idiling, I could however press excelerator and it would respond, but with more noise. The only thing that was done, starter replaced and faulty chassis ground repaired. I also thought some confusion might have been created when the mechanic I was first talking about was one that was on the phone with the sheriff and kept trying to make us believe it was turbo charger going bad, but we're over that now. We had a good trip home and it ran and performed better that ever. :)tommy t.

Re: turbo charger the mechanic said

Reply #43 – May 29, 2011, 07:01:03 am

Tommy, I sure am glad it is behind you now and can appreciate the frustration you went through.
As for the starter hanging engaged, not turning the engine, just removing the teeth, that is not unheard of, it has happened to some of my customers generators who happen to use the Cummins C , John Deere engine and one Detroit Diesel so far.
It appears to be associated with poor battery cable connections or weak battery. Causing the starter solenoid contacts to burn/stick, you were lucky for being there and disconnect the battery cables.
On our generator sets, they are automatic and no one around to disconnect or even know it happened.
I am NOT saying it ONLY happens to the Cummins C series or the Delco MT37 starter, have seen the MT37 and a Denzo starter have this issue seen SO FAR, I am sure it can happen to other starters, it is just the MT37 is a very popular starter used on many different engines.
Good batteries, cables and connections are REAL important.
Hope it is all behind you now.
Cheers

Re: turbo charger the mechanic said

Reply #44 – May 29, 2011, 09:11:03 am

Tommy, I think you educated us all. I would have never thought that the situation could occur. Thanks for the update.

Dave, thanks for sharing your experience as well.

Re: turbo charger the mechanic said

Reply #45 – May 30, 2011, 12:44:55 pm

Tommy,
I have a short story of a friend's Foretravel that had a similar failure but had a different cause that you might want to consider checking into. He has a '95 U320 Cumminis M-11. He took off one day and drove a good distance until he lost power and pulled off to the side of the road. When he walked to the rear of the coach he smell something burning(electrical like) and saw his starter smoking - it was very very hot -paint on it was charred and discolored. What he discovered was that the primary solenoid (mounted next to battery isolator behind rear drivers side wheel - looks just like a boost solenoid - it's Foretravel installed) had locked in the ON position and was engaging the starter the whole time he was driving. The teeth on the starter were gone but the teeth on flywheel were OK. He not sure why the engine stopped (no shut down light). He thinks it might be vapor lock in the fuel line that runs close to the starter. So the point is his starter didn't fail, the $20 solenoid did.

On another note, it sounds like no one knows why your engine kept running eventhought it was the starter that was bad... here's a possible explanation: There might be wiring circuitry that forces power to the fuel solenoid when the starter is cranking.

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