6.5L Diesel, PMD, Thermostat, Power Loss, Injectors, Injector Pump

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

I love my ’96 dually, but have been having problems: My fuel mileage is down to only 13 on the highway and the throttle has become very goosy or jumpy. Often times, while waiting at a stoplight, the engine will surge and blow out a big puff of smoke. One time, it revved way up and I had to turn off the key to stop it. Then it started again and ran fine. It seems to have a mind of its own and I just don’t trust it anymore. Can you help?

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

We really like our 97 K2500 GMC. It looks like new and is great to drive. It has been worked pretty hard pulling our RV, but it has had all the maintenance. Now, at only 167,000 miles the engine seems to have failed. It has a loud clanking sound and it is blowing fumes and oil out of the oil dipstick tube.

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

A mechanic told me that all 6.5’s run hot when towing a heavy load, but I am not so sure he knows what he is talking about. When we are going uphill with the camper and boat, the gauge goes over to about the three-quarters mark, but it didn’t used to go that far. I think something is wearing out or getting weak. Any ideas?

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

My 1994 three-quarter-ton 4x4 truck seems to run fine – until I leave the city and try to run at higher speeds. I don’t even try to pass anyone – it will fall on its nose if I stay in the power. Sometimes it dies when I go around a corner in town and step on the throttle. Do you know what might be wrong?

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

My 1995 K2500 GMC has had six injection pumps put on it since new. Each time the shop replaces the injection pump, the truck runs like new again – for a year or two. The last time we had this done, our mechanic installed a different fuel delivery box. He said that the one mounted on the injection pump was the problem all along, so he installed this new one that is fastened to a finned cooling grid that bolts along side the intake manifold. He said that this would solve the problem we had been having. Well, it has not worked out that way. After 13 months and 23,000 miles, we are right back where we always seem to wind up – with a stalling engine. A friend gave me your magazine and I am thrilled to find information about my truck. I hope you can offer some suggestion that might help us fix this for a longer period of time – we need reliability!

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

Our 1999 Suburban has been a great family car and it has always run well, except for the PMD problem (now fixed). It has 175K miles on it. The problem we are having now is that it does not start well the first time each day. It starts quickly but then shakes, misses and smokes for about 10-15 seconds. Then suddenly, it will straighten up, run smooth and the smoking stops. The local dealer shop told us it needed a new fuel injection pump, but I am not convinced. What should we do?

Volume 1 Issue 2 - 6.2/6.5 Issues and Answers

I bought my 1996 half-ton 6.5 pickup used and do not know its history. I do know that I am freezing now that winter has set in – the heater is lousy and I cannot keep the windshield free of ice. The temperature gauge stays at about 160ºF most of the time and that looks hot enough to me, so I don’t understand what is happening here. A local shop told me that the radiator and heater core were plugged and they estimated $1,085 to fix these. Can you give me some help – something better than $1,085?