Chev HD 3500 Diesel ???

[Ryan03]

The 6.5 td is not neccesarily a bad engine, it is just that when compared to the offerings at the time from Ford and Dodge, the 6.5 was much less powerful and had a life expectency similar to what could be found in many gas engines of the same vintage. By far what most commonly plagues these engines is the DB4 drive by wire injection pump found on the 1994 to 2000 model year engines. The F.M.U. [fuel management unit ] would often take a dump as early as 40k miles and most often by 90k., resulting in a ride on a hook to the nearest service garage for an injection pump replacement, $$$$$$. If you do buy this truck, and end up replacing the injection pump, I would strongly recomend doing what I have done with several of my fleet customers and swap on a earlier 1992 to 1993 6.5 td mechanical injection pump, stanadyne model number DB2, you will also have to obtain the gas pedal and all throttle linkages and brackets from either a salvage yard, or your local G.M dealer, but it is a direct bolt on swap, all fuel lines as well as the injectors and mounting arrangement, timing mark, etc are identical to the electronic pump. The mechanical pump is usualy good for 100 to 125k without problems, hope this helps

 

[Builder]

So basically a 6.5 with 117000 miles, how many more miles is it good for before having problems. What will go first, injector pump? Are they prone to failure. Or will I be replacing head gaskets soon? Will it heat up when pulling my trailer? Will it have enough power on hills to keep up with traffic reasonably well? 117000 miles is nothing for a 7.3. One of my tow trucks with the 7.3 had over 250000 with not much more that a glow plug, oil, filters, and I think I had to flush the block out and add some addative that they recomended on the first 7.3 as they had some corresions problems.

You're asking questions that are literally impossible to answer. When a diesel engine will begin to give the owner problems is a wild guess. How much it will heat up or how fast it will tow depends on how steep the slopes are and how heavy the trailer is plus about a dozen other minor factors. Injection pumps are super expensive on the 6.5TD. I've seen them run 250K with good maintenance, but they're no 7.3L or 5.9L.

The additive you speak of for your 7.3 is an anti cavitation additive that needs to be checked every oil change by sampling your anti-freeze. FW-16 is the Motorcraft part #.

 

[Renze]

The mechanical pump is usualy good for 100 to 125k without problems, hope this helps

hmm... I've never had to even touch a fuel pump, on 250.000 km+ cars or 10.000+ hrs tractors... Nor did my brother, on his 1983 Mercedes 300D which ran over 835.000 km...

 

[Ryan03]

hmm... I've never had to even touch a fuel pump, on 250.000 km+ cars or 10.000+ hrs tractors... Nor did my brother, on his 1983 Mercedes 300D which ran over 835.000 km...

That must be the reason that I have never changed a Mercedes diesel inj. pump, LOL.

 

[KICK]

mostly been my experience that no injection pump has a failure, of its own accord

if water manages to get past the fuel filter, its another story, but that story is one of lack of maintnence or RCI.

 

[workinallthetime]

im going to go out on a limb here and say i have probably been inside more 6.5 engines and 6.6 d-max engines than anyone on tbn. As a GM tech for the past 12 or so years, 6 of that was spent in a medium duty shop. the 6.5 is a good engine, maybe not as neer as powerful as todays truck's but the engine is pretty solid. 9 out of 10 engines i replaced were due to loss of oil either by blown oil cooler lines or some one not ever changing the air filter thus causing the cdr valve to drain the crankcase. the electronic pumps fail mostly due to metal contamination cause by the lift pump seperating, most pumps can be had had for about 500 from your local rebuild shop or about 1500 from gm. stanadyne performance formula should be run in every tank with the 6.5. clean fuel and change the fuel filter every 6 months and it should last another 100k. down here you can by just about any form of 6.5 truck for 3-5k flat bed 1 tons to 3/4 tons. I woked on some bread trucks that had over 300k on the original motor.
as for the d-max, yes it was an isuzu design but the design was used in a 4 and 6 cylinder unit not a v-8, the v-8 was built and desined for gm and now gm is going to have a smaller 5.9 liter for 1/2 tons soon and maybe even cars since the demensions are the same as a 5.3 gas burner.

i would advise you d-max owners to use either the gm or racor fuel filters if you want to extend the life of your fuel system, i quit counting at 30 after market filters to 1 gm filter while doing injector jobs on the lb7 engines.

 

[artfull dodger]

The injector pump on the 6.5 is no worse than the cost to rebuilt the cummins pumps. None are cheap if you have to pay to have it done. A replacement DS4 electronic pump is around $600 from ssdieselsupply ect. Its the labor to R&R it on the motor, then retime the engine. The optimizer is a drop in replacement all the 6.2l and 6.5l applications. You can get a reman unit from Kennedy diesel for just under 5k right now. They use the optimizer block and heads in the reman process. Thats the route I plan to take when the 6.5td in my suburban bites the dust. She is at 199k and running strong. She got new injectors and a IP at 170k, has very little blow by. I plan to upgrade to a fluid damper on the crankshaft, I already relocated the IP electronics to a heat sink on the intake with the ssdieselsupply.com kit. That solves most of the electronic pump issues. If the truck is an auto, going to a manual pump requires a stand alone computer to control the transmission shifting, and those are not cheap. I would rather have a cummins, but I dont care for the dodge truck around it. The Ford 6.9/7.3 is a great engine, but more expensive to replace when it does go boom. It all goes back to how its been treated in its prior life. At the min you will be looking at a injector pump and injectors soon if they havent been done yet.