Posted 9/23/2017 08:11 (#6264975) Subject: 6-71 Detroit diesel oil
Just bought a grain truck with a 6-71 engine, Can I use the same oil in it as I use in all of my other equipment John Deere 15-40 diesel motor oil? Thanks
Posted 9/23/2017 08:41 (#6265034 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
mercer county, il
If you use multigrade oil they like to eat it. Has been a while but oi think it was straight 30wt that we kept around for them. Someone smarter than me will chime in.
Posted 9/23/2017 08:43 (#6265039 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
east central ND
I have a 4-71 two cycle with a blower in an old trac hoe. Local Detroit service manager (older gent who actually new old motors) was very opininated about keeping straight 40 wt in it.
Posted 9/23/2017 09:33 (#6265125 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
SE Nebraska
They would like you to run low ash oil in them but that is hard to find. I have a 4-71 and a 6-71. I use 15w40 in both and have seen no issues after many thousands of hours use
Posted 9/23/2017 09:35 (#6265127 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
Dalhart, Texas
We have a freightliner that will use/leak a gallon a day during harvest if we use JT8 15w-40. Talked to a guy who used to run a fleet of buses that had these engines and he said switch to single viscosity oil and it will stop consumption. I was skeptical, but did it and I have barely added any since. Will have to look to see what oil it was, but I remember having to special order it as nobody here in town had it. I do remember it being very common years ago--the oil that is. Also, there is some specification as to the ash content.
Posted 9/23/2017 09:47 (#6265143 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
Central ND
The guys that run multigrade in a 2-stroke are running on borrowed time, IMHO. With today's oils, nothing but 40 wt. should be used. It is a P.I.T.A, but screamers run such hot oil temps. We had an old truck that had an engine oil temp gauge. Gauge said if oil got over 300° to stop vehicle and run engine for 10 minutes with no load.
Posted 9/23/2017 10:02 (#6265170 - in reply to #6265143) Subject: RE: 6-71 Detroit diesel oil
Davenport Washington
Most of the straight weight oils are no detergent so you don't want to switch to a detergent style or you will have a real mess and probably plugged oil filter. 30 for winter and 40 for summer.
Posted 9/23/2017 18:21 (#6265805 - in reply to #6265143) Subject: RE: 6-71 Detroit diesel oil
Hagen Brothers farms,Goodrich ND
I ran a pile of those Detroit's up until a few years ago. If the engine is at all tired, it will drink 15-40 in big gulps. My least oil consumption on the less than new ones was using Mobil Delvac 30 or 40 wt.
Posted 9/23/2017 11:48 (#6265295 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
Sac & Story county IA
When I got the first one of those, I asked a guy that used those and got very long life out of them. He told me 2 things. Always use 40 oil and never let it idle.
Posted 9/23/2017 12:18 (#6265330 - in reply to #6265295) Subject: RE: 6-71 Detroit diesel oil
Liberty, MO
I drove a 8V71 for a friend a little and he told me than when I stopped for more than 2 minutes to shut it off. If I was parking it at the end of the day the wheels should be the last thing turning, motor was shut off before the wheels quit turning.
Posted 9/23/2017 18:11 (#6265784 - in reply to #6265326) Subject: RE: 6-71 Detroit diesel oil
Central ND
JohnW - 9/23/2017 12:14
There used to be a special API oil classification of CF-2 for 2 stoke diesels but now this classification is listed as being obsolete.
I think any oil rated for use in diesel engines would be OK.
No, any diesel oil is not acceptable. Two-strokes are a completely different animal from any other diesel. Main difference is the sleeves have transfer ports in them. Multigrade oil tends to gum up the rings, which is why there are many stories from guys switching to the proper oil and consumption goes down. Any reputable oil supplier can get SAE 40 diesel oil, so the comments saying it is obsolete are not correct.
Posted 9/23/2017 19:45 (#6265933 - in reply to #6264975) Subject: RE: 6-71 Detroit diesel oil
Fruita CO
Multi-grade or any lighter oil will be more apt to wipe off the rings into the ports & the air box, & aggravate the reputation of slobbering oil...or, if the airbox drain is plugged, accumulate enough oil to cause a runaway. 40 is the stuff...
6-71 Detroit diesel oil
