The Combine Forum banner

21 - 37 of 37 Posts

·
Registered
Joined
·
216 Posts
The oil samples typically show wear metal however if there is a catastrophic failure large chunks of metal will accumulate at the bottom of the pan and in the filter apparently the filter looked good? Are you sure the breather tube going from the PCV to the intake is clear? If the engine can be run enough for a cut out test you may be able to narrow down a cylinder to look at. We had a combine delivered last year and it was 20 below out they let the machine sit on the trailer in the shop overnight and started it the next day. They ran it outside and were hooking up the trailer to move it out and during that time the PCV valve froze up. They went to move the combine back in, throttled it up, and the entire valve cover blew up due to the pressure in the crank case, it made a huge mess. I don't know how much oil would get flung out of the back of the engine with all the gears rotating and the cover blown off but I would have to think it would be a pretty good amount. I guess I would hook up the manometer with a new PCV cover and filter and start the machine, monitor the pressure, and if it is way high at idle something is seriously wrong. Then I would raise the RPM and monitor until your at high idle. If it's still under spec run it under load and watch it then record what you get. At the end of this remove the PCV filter and see if it's saturated in oil it should not be after running this little. If the PCV system is not blocked and the crankcase pressure is within spec like the shop said it is you will not blow another cover. If the crankcase pressure is high and the breather system is clear and functional it's time to start looking into it maybe the rings are shot or the cylinders are glazed and allowing combustion pressure into the crankcase. How many hours on the machine?
 

·
Registered
Joined
·
11 Posts
Discussion Starter #22
The oil samples typically show wear metal however if there is a catastrophic failure large chunks of metal will accumulate at the bottom of the pan and in the filter apparently the filter looked good? Are you sure the breather tube going from the PCV to the intake is clear? If the engine can be run enough for a cut out test you may be able to narrow down a cylinder to look at. We had a combine delivered last year and it was 20 below out they let the machine sit on the trailer in the shop overnight and started it the next day. They ran it outside and were hooking up the trailer to move it out and during that time the PCV valve froze up. They went to move the combine back in, throttled it up, and the entire valve cover blew up due to the pressure in the crank case, it made a huge mess. I don't know how much oil would get flung out of the back of the engine with all the gears rotating and the cover blown off but I would have to think it would be a pretty good amount. I guess I would hook up the manometer with a new PCV cover and filter and start the machine, monitor the pressure, and if it is way high at idle something is seriously wrong. Then I would raise the RPM and monitor until your at high idle. If it's still under spec run it under load and watch it then record what you get. At the end of this remove the PCV filter and see if it's saturated in oil it should not be after running this little. If the PCV system is not blocked and the crankcase pressure is within spec like the shop said it is you will not blow another cover. If the crankcase pressure is high and the breather system is clear and functional it's time to start looking into it maybe the rings are shot or the cylinders are glazed and allowing combustion pressure into the crankcase. How many hours on the machine?
I'll give all that stuff a go next week, this other dealer is kind enough to let me work alongside their mechanic in their shop to save on labor. Machine has 1400 separater hours on it, we don't have a long season like some areas.

I have thought about blocking the line that goes back to intake and running a hose off filter housing to atmosphere. If the cross hatch was gone off cylinders would that show up in the oil test? Its something I've thought about. As I said before my experience as a mechanic is very limited, but I would think if I had a hole in a piston or some other catastrophic failure things would sound bad at high idle. I believe the shop tested cc pressure at high idle and found nothing suspicious, but the motor was cold. When the motor is cold I can run at full throttle, but once things get warmed up and under a load that's when the problem occurs. Would having that filter in backwards for 20 minutes cause severe damage like were talking about?
 

·
Registered
Joined
·
632 Posts
one cylinder gone would pulse in crankcase. I ran mine to atmosphere instead of to the compressor side of turbo
pull hose and check whats coming from it. Check if the compressor side of turbo and lines to the air to air are wet with oil
 

·
Registered
Joined
·
5,499 Posts
Since your oil analysis is fine but it requires both heat and heavy loading to pressurize the crankcase you may be experiencing a head gasket failure. It’s rare to have a gasket fire-ring leaklng into an oil passage port in a gasket, but it sounds logical here. As does a cracked head, but I think it’s less likely. If it’s just the headgasket, you’ve dodged a bullet.
 

·
Registered
Joined
·
1,158 Posts
Be sure to check and see if oil has entered the exhaust. If it has chances are DOC and SCR chamber are fubared. Not cheap to replace either.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #28
one cylinder gone would pulse in crankcase. I ran mine to atmosphere instead of to the compressor side of turbo
pull hose and check whats coming from it. Check if the compressor side of turbo and lines to the air to air are wet with oil
Was your issue as extreme as what I've described where it blows all the oil out of that housing?
 

·
Registered
Joined
·
632 Posts
no it kept spraying an oily mist into turbo and then it would congeal in the air to air.It lost all power, but it started at that filter ,I found out on the tractors there is a reto kit for that ccv system
 

·
Registered
Joined
·
11 Posts
Discussion Starter #30
Update: finally got the time to pull the motor apart. 2 cylinders have heavy damage to cross hatch and the remaining 4 have some level of damage. Extreme carbon build up on top of pistons. No broken rings. Turbo seal went out and was blowing oil on top of pistons. Carbon build up on top of pistons and between piston and sleeve caused the cylinders to wear out and resulted in the extreme blowby. Unsure what caused turbo seal to go out at 1800 engine hours.
 

·
Registered
Joined
·
1,315 Posts
I was wondering how you were making out with that thing.
Geeze talk about bad luck.
I wouldn't have guessed a turbo seal would cause that kind of wear to the liners.
That seal possibly been leaking for many hours?
I guess its going to be a new sleeves and pistons job and turbo then.
 

·
Registered
Joined
·
5,499 Posts
The turbo seals are going to be subject to any of the aforementioned mayhem discussed about crankcase pressure, the oil galley in the turbo returns to the crankcase. I’m glad my old tractor has an inch and a half diameter crankcase ventilator and has been purring along for 39 years with 15 gallons of oil keeping its twin turbos healthy.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #33
Yeah sleeves, pistons, main and rods at least. Bearings have carbon speckling on them. Then obviously a new turbo. Mother case quotes 77k for a remanned motor. So I'm thinking a rebuild is a no brainer. Crank, cam, and head were all fine.
161063
161065
161066
 

·
Registered
Joined
·
1,315 Posts
I would be interested to see once that piston is pulled out of the sleeve in picture #1.
Only one area of the sleeve is showing hard scuffing, a possible broken ring problem?
Picture #3 looks wore right out?
I see no evidence of any honing marks.
Sure looks gummy at the top of the sleeve like it has been pumping lots of oil.
Only thing I can think of is the extra oil coming from the turbo increased the cylinder pressure enough that this caused seriously accelerated wear to the rings???
This engine has an air to air intercooler?
Might want to get that thing cleaned out of any sticky oily mess inside it.
 

·
Registered
Joined
·
1,315 Posts
Just thinking this situation through and going back to that thread on red power.
That very last post in that thread says there are improved thermostat housings??
This engine didn't have any thermostat issues???
Running cold and possibly rich could lead to cylinder washing.
I'd definitely get the injectors checked while you are this deep into things.
I would be really tempted to vent the breather to atmosphere and leave it that way.
 

·
Registered
Joined
·
632 Posts
do you run this yourself or hired help
have seen this a few times with cold start and put to load
aluminium piston expands faster than cast sleeve and scores liner
 

·
Registered
Joined
·
11 Posts
Discussion Starter #37
I run this myself, and I wouldn't suspect improper warm up is a culprit as its usually 90-100 F during my harvest season. I had a bad thermostat two years ago, but replaced it as soon as I noticed it was reading low. It was giving a low reading on the thermostat so I believe it was under cooling not over cooling. Im going to have all the injectors tested and replace any that are suspect.
 
21 - 37 of 37 Posts
Top