Combines N5 engine overhaul

Usually N5_6 engines invite many replies, but maybe many guys are in the field. Based on what has been said before, you were due for rod bolts some time back. I would sample oil before doing anything else, but in your situation you can't wait much longer to do that. Page down and read earlier discussions. Tom in MN

Tom, unless I missed something along the way, the N6 has the problem engine because it turns 200rpms faster than the N5 and produces 30 more hp. My N6 turns at 2600 high idle and the N5 turns 2400 high idle, that is the reason for the underhaul(rod bolts and bearing)on the N6 being critical every 1500 hrs or so. The N5 and N6 use different engines 670I and 670HI. The 670HI are the same engines the were in the 7080 and 7580 and prone to failure. The 670I is the 7060, 8050, 8070 engine and very reliable engine.

John Thanks for the clarification. I was merely passing along what I remembered from previous discussions, as I have never owned an N5 or N6. What would you suggest that he should doIJ Tom in MN

As I stated in my other post, the N6 is the engine that is prone to failure and needs attention every 1500 hrs or so because they turn 2600rpm high idle. The N5 on the other hand were not as well known for engine problems because they were not turning as fast and not producing that extra 30 hp. If you have gotten 3300 hrs out of that engine with out failure... an N6 would of probably blown up by now, but any time you now feel the need for the overhaul would be good. From what I have heard here in the states the overhaul is 1_2 the cost of a Cummins conversion. And I have run both engines and think they are great engines. My N6 had its second underhaul last August at 3100 hrs. To me, it is cheap insurance on an N6. Also told me that I was going to get 5 to 6000 hrs on the engine before overhaul too.

You say you are new to this site so you may have missed post on 670T engines back on 11-27-00. You would have the 670I but you may get something out of that post. You do want to watch your hi idle to see it isn't creaping up on you for I have seen low and hi reving engines get up to 3000 plus RPM. These engines have a cool scream to them at that but I wouldn't want to stand to close to them. Be sure to use the long oil filters and warm engine well (140F) before reving and or putting to work. I've seen guys ruin a high reving 7080, 7580, or N6 motor in less than a 1000 hours and than again many are still going strong with well over 5000 hours. The lower reving lower output motors didn't give as much trouble but could fail in exactly the same way. It boils down to how was that engine treated and what was it asked to do each and ever day it was put into service.