After driving my M1009 for about a week and half I think its a great truck.
And then I see people cutting down the 6.2 diesel. For what it lacks in power it seems to make up for in fuel consumption, reliability, cheap parts, and ease of maintenance.
25 years of service seems to be pretty good to me.
Note that I am NOT a 6.2 diesel basher. I own over twenty 6.2 powered vehicles and have been working on them, and driving them since they were invented.
That being said, the 6.2 is a light-duty, low-torque diesel engine . It uses a rotary distributor-type injection pump that is the WORST thing to have in areas of high heat and using thin fuel (like military JP
. I suspect the 6.2 was a terrible choice for military duty, and the ARMY et . al has written aobut their regrets, many times.
There is no way a 6.2 engine ever gave "25 years of service" in the military. Not many in private use have lasted that long either.
No personal dig intended, but owning one for a week is not exactly a fair test for longevity and reliablitly.
In regard to fuel mileage - getting 18 MPG with diesel that was 50 cents a gallong cheaper then gas - when gas trucks got 12 MPG - certainly made the diesel cheaper to run. Now?? Here in NY, diesel fuel is 30-40 cents more then gasoline, per gallon. A diesel Blazer can get a best around 20 MPG, and so can a newer gas powered equivlent SUV that runs on a now cheaper fuel.
GM made many goofs with early 6.2 and many fixes had to be done along the way. So no, it was not very reliable. It started out with many problems in 1982, and by 1992 had many worked out (but not all). The Army claims that the 6.2s they used overseas rarely lasted more then 2000 miles.
I wll say that the miltary K5 Blazer is a better rig then the civilian version -mainly due to using the TH400 trans instead of the 700R4.
I agree that parts are plentiful and cheap IF you know how to scrounge around. I do NOT agree they are simple to work on. Simple for a well trained, "old-school" diesel tech - yes. Many mechanics that get by working on gas engines are clueless with diesels. How many independent mechanics do you know that fix their own injection pumps, fix and/or test their own nozzles, own a diesel timing light, etc.? I bet not many.
Here is one of many articles written about the 6.2 and problems in military use:
July 2004 issue of National Defense magazine, "Army Ponders New Diesel Engine for Humvee Trucks," notes that maintenance nightmares have been experienced in Iraq because engines regularly break down and often must be replaced after only 1,000 to 2,000 miles of operation. Much of the blame for this is placed on the bolted-on armor protection that adds weight to the vehicles. However, the inability of the rotary-distribution, fuel-injection pumps to operate satisfactorily for sustained periods of heavy-duty operation is probably a contributing factor, especially when low-viscosity fuel is used in a hot environment. Interestingly, the fuel-injection pumps in many, if not all, of the HMMWVs operating in Southwest Asia have been retrofitted with Stanadyne's Arctic Fuel Conversion Retrofit Kit. This kit apparently has done little to offset the significant increases in maintenance that have been experienced recently.
Rethinking the SFC
Combat operations that occur in higher temperature environments certainly will intensify the operational and maintenance problems of diesel-powered vehicles and equipment with fuel-lubricated fuel-injection pumps. Since almost half of the Army's diesel vehicles and equipment have rotary-distribution, fuel-injection pumps, a solution is urgently needed."