1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

Gehl 5640 Engine Lope

Discussion in 'Skid Steers' started by TFaoro, Sep 21, 2017.

  1. TFaoro

    TFaoro New Member

    Joined:
    Sep 20, 2017
    Messages:
    4
    Location:
    Denver
    Hello everyone, I'm new here and have an issue with a Gehl 5640 I recently purchased.
    For some reason, whenever I start it and it's cold, the engine surges / lopes pretty bad. It doesn't miss at all, but the rpms fluctuate quite a bit. If I increase the throttle, it continues to surge / lope up until about 1/2 throttle then becomes smooth.
    After 20 min or so when the oil reaches 140F it smooths out and idles normally.
    I've been around diesels my whole life, but never messed with a Deutz (BF4M2011)
    I have replaced the pre-filter, main fuel filter, and lift pump. I've also check all of the connections and the fuel is flowing from the tank very well.
    I've been told things like governor, fuel supply, it's normal, etc. I appreciate any advice you guys might have!
    Here's a video of the skid steer idling cold
     
  2. 62oliver

    62oliver Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    67
    Location:
    NWO
    Since you got no replies yet, I'm no pro, but it doesn't sounds like anything I'd get too worked up about. I would guess governor related FWIW.
     
    mikebramel likes this.
  3. thepumpguysc

    thepumpguysc Senior Member

    Joined:
    Mar 18, 2010
    Messages:
    5,649
    Occupation:
    Master Inj.Pump rebuilder
    Location:
    Sunny South Carolina
    Googel that engine & add idle adjustment.. I'm pretty sure there is an external idle "surge screw" adjustment..
     
  4. TFaoro

    TFaoro New Member

    Joined:
    Sep 20, 2017
    Messages:
    4
    Location:
    Denver
    I understand what you're saying, but I've never been around a Gehl that has done this.
    I'm probably going to sell this skid loader, and I think I can get a much better price if the engine is running smooth from idle to hot.
    I'll see if I can find something. Thank you for the advice!

    I did speak with a dealer yesterday afternoon and they seemed pretty persistent about air getting in the fuel somewhere, so I will likely replace all of the fuel lines and clamps today too.
     
  5. Georgia Iron

    Georgia Iron Senior Member

    Joined:
    May 7, 2012
    Messages:
    551
    Occupation:
    Concrete building slab and grading contractor
    Location:
    Marietta, Georgia
    It sounds a bit metallic. If it has been ran real hot, it will have lower bearing wear, which can cause it to run weird due to injector clearance being out. It smooths out when the engine expands a little due to heat. Maybe wear in valves or top end to.

    Or it could just be a fuel pump adjustment. Does it burn oil and smoke any at first start up?
     
  6. TFaoro

    TFaoro New Member

    Joined:
    Sep 20, 2017
    Messages:
    4
    Location:
    Denver
    I'm not sure about the engine history. I bought it used not long ago.
    On startup, it has the normal puff of black but no blue smoke that I've noticed.
    It's weird because when it first starts it'll idle normal for 2-3 seconds then starts to run like you hear in the video.

    The metallic sound sounds like valves way out of adjustment to me. It's right around 3k hours and who knows if the valves have ever been adjusted.
    I'm going to try all new fuel lines and adjusting the valves tomorrow and see if that changes anything. I'll report back and let everyone know.
     
  7. check

    check Senior Member

    Joined:
    Apr 1, 2012
    Messages:
    798
    Location:
    in the mail
     
  8. check

    check Senior Member

    Joined:
    Apr 1, 2012
    Messages:
    798
    Location:
    in the mail
    Could you please explain that? Which bearings are you referring to and which clearance? Between piston and injector?
     
  9. mikebramel

    mikebramel Senior Member

    Joined:
    Jul 16, 2012
    Messages:
    1,612
    Location:
    milwaukee
    hopefully not the original belt
     
  10. Georgia Iron

    Georgia Iron Senior Member

    Joined:
    May 7, 2012
    Messages:
    551
    Occupation:
    Concrete building slab and grading contractor
    Location:
    Marietta, Georgia
    Having posting issues..
     
    Last edited: Sep 24, 2017
  11. Georgia Iron

    Georgia Iron Senior Member

    Joined:
    May 7, 2012
    Messages:
    551
    Occupation:
    Concrete building slab and grading contractor
    Location:
    Marietta, Georgia
    Lets try again
     
    Last edited: Sep 24, 2017
  12. Georgia Iron

    Georgia Iron Senior Member

    Joined:
    May 7, 2012
    Messages:
    551
    Occupation:
    Concrete building slab and grading contractor
    Location:
    Marietta, Georgia
    Maybe 4 times is a charm. Keep loosing what I write.

    Sorry that did not come out right. (weird due to injector clearance being out) should say "run weird due to injectors failing and internal clearances being out".

    And to expand upon that The crank shaft can be spinning in worn bearings and moving up and down, worn bearings can cause low oil pressure and increased internal heat, cam lobes can loose metal off the lobes and cause valves to open incorrectly, the piston can gall the cylinder walls and cause the motor to smoke and burn oil. And so on..

    I have friend that is a mechanic and he says he does not want someone elses junk... he wants to know exactly how something has been used and he does not want to work on problems created by others. He calls contractors the worst.

    I buy used equipment and so far I have been lucky and bought great used machines. I normally check the function and load test the machine to make sure power from engine and hydraulics seems right so that has helped me avoid getting something that is completely shot.

    A question I have that I could use more understanding on from you guys is the gray area between runs good and complete failure due to an overheat. Say a extreme overheat has happened, metal in filter, engine misses a little till warm or all the time, more than normal noise in the engine. I was told during an overheat the water turns to steam and cooks an engine from the top down. Is that a true statement? What is causing the noise - is it valves burnt or opening an closing incorrectly, are the rockers going out, does cooked oil ruin everything it touches etc? What will happen if you change the oil, pour lucas in and keep using it. Assuming it still has some oil pressure, can the engine live on and still make money or is it still likely to have a major part failure once an extreme overheat has occured? Does the heat ruin the mechanical injectors? I am not talking about then most modern diesel engines but the slightly older diesels from the late 80s / 90s and early 2000s
     
    Last edited: Sep 24, 2017
    check likes this.
  13. Delmer

    Delmer Senior Member

    Joined:
    Jan 4, 2013
    Messages:
    6,512
    Location:
    WI
    The steam doesn't hurt anything. In the old days it was found that engines could allowed to steam away as a cooling method with better results than average for the day, engines were heavier and lower output in those days. A high output engine with steam pockets will have localized hot spots, that's what does the damage, cracking, expanding and loosening gaskets. If there's metal then the pistons siezed most likely, lucas is not going to restore worn rings, galled pistons and cylinders. Connecting rods are next, especially the top end. So the "cooking from the top down" is the most accurate part of that statement. I don't think there's anything wrong with the cooked oil in most cases, worn out and needs to be changed, but the oil didn't cause the problems, the lack of normal temp oil might have.
     
    Georgia Iron likes this.
  14. TFaoro

    TFaoro New Member

    Joined:
    Sep 20, 2017
    Messages:
    4
    Location:
    Denver
    I tore it apart this weekend and found a pretty new looking belt - With the hours it has that's a very good sign!

    Again, I'm not sure if the engine has been overheated or anything.
    I'll be long winded here for a minute. So I bought this thing out of the south west side of Arizona. I'm from Colorado. (830 miles / 12hours) I had long conversations with the owner about the machine and he reassured me about the condition of the machine (Bought it from a dealer)
    8 hours into the trip I blew an injection line on the truck and continued to drive for the next 4 hours until I got there.
    After seeing every bushing on the machine worn out and the engine loping, I didn't want to buy the machine. I was livid, but he had a truck I could use the injection line off of. I literally bought this skid steer so I could make it back home.
    I've replaced every bushing in it, and am now trying to get it to run right so I can sell it as a solid machine.

    So this weekend I set the valve lash and pulled the timing belt cover off. After the valve lash, the engine definitely sounded much quieter, but it didn't help the lope. There is a pretty new looking belt under the cover, so that's a big plus.
    There is an external screw near the governor that the book calls "Speed governor with minus adjustment" - turning that either did nothing
    There is also a screw under the timing cover called the "Idling Capsule" - turning this in raised the idle, and screwing it out lowered the idle.
    I did get around to replacing all of the fuel lines as well - That didn't do anything.

    Any advice on where to go from here??
     
  15. Georgia Iron

    Georgia Iron Senior Member

    Joined:
    May 7, 2012
    Messages:
    551
    Occupation:
    Concrete building slab and grading contractor
    Location:
    Marietta, Georgia
    I can't say for sure. You could check your compression. Assuming the engine is good, it's either air or fuel. So air fliters then look towards the fuel pressure. You could break the lines loose near each cylinder to check and see if it changes. Could be a dirty inline screen or filter. I had a tractor that did something similar once and it turned out the small fuel pump that pressures the main pump had wear and the screens were dirty inside of the primer pump.

    Good luck and let us know what you find.
     
  16. mikebramel

    mikebramel Senior Member

    Joined:
    Jul 16, 2012
    Messages:
    1,612
    Location:
    milwaukee
    If the belt is new, try retiming it, recent problems > recent work LOL
     
    Delmer likes this.
  17. Swannny

    Swannny Senior Member

    Joined:
    Jan 10, 2012
    Messages:
    259
    Location:
    USA
    The idle hunting in the gehls with the deutz seems to be in machines that have sat for a good period of time. Maybe the fuel has gone a bit too stale...maybe algae growth?

    I've had it in 5635 and 40's that have had low hrs., but prob not as bad as yours is loping. Just pour a bunch of seafoam in it and run the heck out of it...most likely will go away. All the ones I did it to corrected themselves. Something sticking in the IP is my hunch.