View Full Version : Diesel questions
muddstopper
08-31-2005, 08:58 PM
Engine in question, diatshu 3cly vanguard 31 hp turbo diesel.
Problem is. Engine was running fine, only has about 400hrs on it. Mowed lawn, about 15 min total run time, shut engine off for about 5 min and when recranked it knocked. Loaded on trailer and took home. Set on trailer for a few days before trying to unload. When cranking the engine seemed to be low on compression, used small squirt of either and engine fired but didnot knock. White smoke came from exhaust. First thoughts blown head gasket but smoke seemed more unburnt diesel that water. Unloaded tractor and parked in garage. Total run time about 5 min. Shut engine down and it started to puke water. Temp guage said 180. Again thought blown head gasket or cracked head. Tractor sat in garage for a week and cranked to trouble shoot. Engine cranked fine still white smoke but no compression in radiator and smoke was very oily as in diesel fule, not motor oil. Almost as if tractor wasnt fireing and just pumping pure diesel mist out exhaust. Ran tractor for a few min and it never got hot or puked any water. Shut down engine and havent touched since. I am leaning toward blown head gasket or cracked head but this isnt making any since. Pukeing water but not hot and no compression in radiator, Low on power and spewing diesel out the exhaust. Knocks one time and not the next. seems low on compression and wont fire without either one min and then cranks fine the next time. All starts where cold starts after the tractor had sat unused for several days. Any opinons before I tear this engine down.
MBDiagMan
08-31-2005, 09:59 PM
You should start your diagnosis with a compression test. If compression is low do a leakdown test and listen for where the air is escaping. If you hear it coming from exhaust it's an exhaust valve, if through the air filter it's an intake valve, if through crankcase breather it is ring/piston/cylinder.
Best of luck,
Doc
Dirty Water
08-31-2005, 11:56 PM
You probably got water in the fuel. This will RUIN the injector pumps and injectors on a diesal.
You probably have an ruined injector just dumping fuel into the cylinder, causing both the knock (running on 2 cylinders), and the smoke.
The easiest way to tell is to open each fuel line to the injector (carefully), one at at time and if the engine does not run worse when you do this you have found the bad injector.
muddstopper
09-01-2005, 05:52 PM
John, I am hopeing you are right. wont know for sure untill I get home and have some time to check. I plan on looseing the fuel lines to each injector, one at a time, to see which cylinder is messing up. Once that is determined. I am just going to swap the injector out to another cylinder to see if the problem moves with the injector. I will do compression checks as i swap injectors. Big concern is, if the injector is bad, would that make the machine run hot and puke water?? I also plan on doing a coolant chamber pressure test by removing the radiator hoses and pluging the inlet outlets and then pumping air pressure in the chamber and see if it leaks off. In fact i just might do the air test first. If air leaks off, I know for sure blown headgasket or cracked head and a teardown is in the near future. Of course once i get a chance to check the engine out, the problem might be obvious and I wont have to do all that checking, just start wrenching. I think this engine doesnot have steel sleeves in the bores, if not can one bore out the block and install oversize pistons. I am pretty sure it is an aluminum block but not certain about that. I worry about scaring of the block if it has just been pumping fuel and not burning it. Of course it hasnt ran much since it started acting up but it doesnt take a long time to really screw things up.
Dirty Water
09-01-2005, 10:21 PM
If you have a bad injector, go ahead and replace/rebuild all three.
Though it cost me $700 to have all three injectors and the injector pumps rebuilt on my Duetz (Only reasion I know how to diagnose this problem now :p )
muddstopper
09-03-2005, 12:02 AM
Well John, you hit the nail on the head. I didnt do a compression check because I didnt have the right adapter but when I loosened the lines one injector would spew foam instead of fuel. The engine would knock when I tighten the line back up. I swaped the injector with another one and the problem also moved with the bad injector. The injector is sticking intermittly and when it isnt sticking the smoke clears and the engine runs fine. I orderd new injectors today. I think you are also right about the water. My wife filled the machine from a can of fuel that had been setting outside without a cap for several weeks. I had planned on using that fuel for a brushpile. cant say for sure the can of fuel had water in it, but if it didnt it sure missed a good chance to have it. I will be draining the fuel tank before running the tractor anymore.
Dirty Water
09-03-2005, 03:35 AM
Drain your tank and throw a can of HEET in with the next fill up, if theres any water left in there, that stuff will take care of it.
Good luck :)
lawnmaniac883
09-05-2005, 09:47 PM
Ditto the bad injector, was gonna suggest that after hearing the white smoke part.
muddstopper
09-06-2005, 05:40 PM
Should have new injector in a day or two. Dealer said they shipped it today. I must admitt, the durn thing had me puzzled for a littl bit. it was doing wierd things at different times. I still havent figured why it puked water after running only a few minutes. The injector also works fine at times. I mowed my grass with the machine this weekend and it never missed a beat, that is until i shut if off and then recranked it a few mintues later. Then it hammered like a gris mill and smoked like a train. I was mowing with it to see if it would get hot but it never did. Didnt even act up until after I was finished and I shut it down and recranked it.
kenkmowerman
09-09-2005, 04:24 PM
Engine in question, diatshu 3cly vanguard 31 hp turbo diesel.
Problem is. Engine was running fine, only has about 400hrs on it. Mowed lawn, about 15 min total run time, shut engine off for about 5 min and when recranked it knocked. Loaded on trailer and took home. Set on trailer for a few days before trying to unload. When cranking the engine seemed to be low on compression, used small squirt of either and engine fired but didnot knock. White smoke came from exhaust. First thoughts blown head gasket but smoke seemed more unburnt diesel that water. Unloaded tractor and parked in garage. Total run time about 5 min. Shut engine down and it started to puke water. Temp guage said 180. Again thought blown head gasket or cracked head. Tractor sat in garage for a week and cranked to trouble shoot. Engine cranked fine still white smoke but no compression in radiator and smoke was very oily as in diesel fule, not motor oil. Almost as if tractor wasnt fireing and just pumping pure diesel mist out exhaust. Ran tractor for a few min and it never got hot or puked any water. Shut down engine and havent touched since. I am leaning toward blown head gasket or cracked head but this isnt making any since. Pukeing water but not hot and no compression in radiator, Low on power and spewing diesel out the exhaust. Knocks one time and not the next. seems low on compression and wont fire without either one min and then cranks fine the next time. All starts where cold starts after the tractor had sat unused for several days. Any opinons before I tear this engine down.
White smoke is almost always the result of water in the cylinder head although at some times, as in when a exhaust valve is stuck open diesel fuel can spray and appear white. If it is water it can be a very slight and undetectable to the naked eye crack anywhere in the cylinder from the head, valve cavity or block.
Dirty Water
09-25-2005, 03:58 PM
any updates?
muddstopper
09-28-2005, 08:41 PM
The injector fixed the smoke and power problems. The radiator cap was bad letting the water spew out the over flow but didnt seal well enough to pull water back from the little overflow jug. Problems fixed for now.
Thanks for all the helpful suggestions from Jon and everyone else.
grass_cuttin_fool
09-28-2005, 09:17 PM
Another way to find which injector isnt firing correct is to use an infared heat gun. Test the exhaust at each cyclinder at the head and the one that isnt firing is gonna be 20 - 30 degrees colder. Before that we used to run the engines and grab ahold of the manifolds and test by hand, that was on the 855 big cam cummins.
muddstopper
09-29-2005, 05:55 PM
loosening a fuel line is cheaper than buying a infrared heat detector and a lot easier on the hands than grabbing a hot manifold.
grass_cuttin_fool
09-29-2005, 08:20 PM
Actually the heat temp gun is less than a 100 bux. It can be used to check the opening temps of thermostats, and even the temp of wheel bearings, it can be a good little diagnostic tool. Also to check the mainfolds by hand, start feeling them soon as the engine fires and which ever 1 you can hold on too will be the bad one. The proper firing ones will soon get too hot to hold on too but most of the time it is that noticeable that you can still touch all of them . The one that is miss firing just never changes temp from the start
muddstopper
10-02-2005, 12:48 PM
What you said makes sense, if's it not fireing it shouldnt get as hot as the ones that are fireing. Just use common sense before grabbing a hot manifold. I dont know if I have a need for a heat detector, or not enought to warrant the cost. The one thing I do wish I coud find at a reasonable price is a handhelt Tack for checking shaft speeds. If you know where a good one is for $100 bucks let me know. I am always trying to figure how fast I am turning a specific jack shaft, different attachments take different speeds, and always end up guessing about the gearing.
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