6.5 L Diesel Strange Occurance....

This is a 6.5 L turbo Diesel 2500 4X4. Runs well between fixes, recent diagnosies have said it was running strong, nothing going on, just two weeks ago. A problem in last summer's heat was this fuel sensor that over heated. Hope your familair, diesel shop said it was very common problem. It was moved to a cooler spot, a finned cooler added, yet still for some reason went through 3 or 4 of this $50 part. It happened so soon after the first one, warrenty carried me the whole way, I only paid for the first one. Then it seemed as the cold wheather set in things went fine. When this part went, it would stall when hot, it would sometimes start afterwards, but would stall again when put into gear. Before stalling it used to choke a few times, eventually ending in a stall and weak restarts.

Today, another hot day something unusual happened. Miles down the road and well warmed up, after turning onto the highway, I felt a reasonally big surge. A smooth, seemling controlled rapid increase in speed for about 3 or 4 seconds. This was followed by an engine light, the little orange engine illuminated. I pulled over, truck running normally and turned the engine off. I then restarted as usual, the engine light remained off and I continued on my way.

I called my husband, (working out of town) he warned me that some years ago someone told him that they had this same engine in a truck. In town, apparently this truck accellerated on it's own nearly running over people on the street. His breaks bearly helded him back, and he would never own one again. So I've come here today to see if this is something that was common for these engines? Has anyone heard of this? Perhaps it is this sensor again, since it does control fuel feed but reacting differently this time. Have to drive it out of town this weekend, no time until at least monday to get it to my favorite diesel shop (TABER DIESEL Taber Alberta) where they say they because a light came on they can tell what happened for it leaves some kind of code messege. Either way we will see what happens, hope it's not fuel injectors, for the cost I wonder if that would be worth fixing or not. They were replaced ages ago free of caharge for they were on warrenty or were recalled, I cant remember. Like I said it was ages ago.

You need to get it to the shop and get it checked out.
Good luck

Your experience is all to common with these 6.5's. The PMD module that controls the fuel orginally came on the vehicle attached to the injection pump for cooling. This was not the best situation due to the amount of heat generated by these modules. An external cooler as you described is the best solution, however if the PMD module was not replaced with the OEM design (stanadyne) they are suceptable to premature failure. Have the codes checked, many times the coolant sensor on these go bad as well. If all else fails, make sure you get the OEM module. Have the transfer pump tested as well, these have a tendency of failure as well. Once again OEM design gives the best results and longevity.

all i can say is Pump Mounted Driver, pmd design flaw by GM they get to hot and shut down