Engine/Transmission (1998.5 - 2002) 2002 3500 concerns

[Stake Man]

At the prodding of a friend, I just joined TDR. Now I hope I can get some answers the dealer wont/hasn't given me.



The company recieved the truck on the 28th of Dec 2001. It now has 75k miles on it. Ever since new it has had poor fuel milage(13. 5-14. 5 city or highway) The dealer has never been able to find out what was wrong. At around 55k I was on a delivery(pulling a grade) and the engine started to knock bad. All the gauges were reading fine. I stopped at the summit and all went away. Shortly after that I was towing a car to the races and it happened again. Couple days later, the CEL came on. Went to dealer and they replaced the Injection Pump. Couple months ago(mid/high 60k) was towing again and it happened again. I took it back to the dealer and they couldn't find anything wrong. Then tonight I was looking through the TSBs and find this one 09-008-02 about the problem I was complaining about. Will this T-Stat really fix the intermittent problem I am having or is there another underlying problem? Would the T-Stat also fix my poor fuel milage? Why would the Injection Pump go out after this problem? After reading about the lift pump problems, any way that could be related? FWIW, its the origional lift pump(dealer wouldn't replace it when they did the injection pump).

 

[rkressg]

First off, welcome to the TDR. You will find copious amounts of information for you and your truck here. Now down to business.



I can only suggest getting a set of gauges (assuming it is your truck and not a company truck). You should install a mechanical boost and fuel pressure gauge, a pyrometer, and a transmission temp gauge (only necessary in an auto). A poorly performing lift pump can cause damage to the internal pump assembly and rotor inside the VP44 (fuel injection pump) and potentially cause a very large repair bill.



What can cause poor engine economy performance is a failing IAT (intake air temp) sensor and a failing MAP (manifold absolute sensor). Depending upon driving conditions, transmission, rear-end gearing, and driver, 13. 5-14. 5 mpg is not too low. I noticed you are in California, it could just be the CA blend of fuel that is causing poor mileage (I have never run fuel from CA).



With regard to a T-stat causing the problem, I am not sure. There were a batch of poor performing T-stats that came from Cummins. You can tell if you have one because when you tow, the engine temp will move up and down, it should stay at a constant 190degF. I have never seen a T-stat cause a problem with the VP44, the only relation to engine temp is, when the engine (computer reads) that the coolant temp exceeds 240degF, cut back engine performance. I am not saying that it can not cause a problem, I just have never seen it as a problem.



If you have a local Cummins dealer, I would strongly suggest picking up a new lift pump. I will guarantee that the original one is, if not dead, dying. The pump should supply a minimum of 7psi at any throttle position. Your over all problem is probably the lack of proper fuel pressure/volume to the VP44. If this one is knocking already, then it also has a good potential for internal damage also.



Also, check for any codes stored in the computer. This can be done by turning the ignition on, off, on, off, on and do not start. Look at the odometer, it will flash something like P... then Pdone for the PCM then it will do the ECM in the same fashion. If you get a p0216, p1688, or p1689 these codes are indicators of a failing/failed VP44, where replacement is usually the only fix.

-Rich

 

[RJPotts]

I had a p0216 code and the dealership said that the VP44 was fine, and replaced the lift pump, does this sound normal or did they not want to spend the money to fix the injection pump? I was curious, and expecting the VP44 to fail soon. About to go clear the codes and see if it pops up again. No difference in fuel economy but I had the dead/soft pedal.

-R. J.

 

[monkfarm]

I wonder if you have any turbo leaks also around the plumbing. I know some mechanics I have had are pretty sloppy about tightening that up, and I had a hose that was completely disingaged from the system.

 

[rkressg]

RJPotts, a p0216 code indicates a timing circuit malfunction with the VP44. If your truck has this code, it almost always incidates a dead/dying VP44. I am not suprised that they (the dealer) tried to get out of fixing this.

 

[Stake Man]

The truck is a company truck. But I might be able to convince them on a set of gauges. I checked for codes tonight, but nothing came up. I'm glad to see they kept the self diagnosis feature on the trucks(same as on my 80's turbo cars).



I have an EGT gauge that I'm pulling out of my Omni. Its a 600-1600 range. Will that work or do I need a full sweep(0-1600)?



The fuel milage is the same no matter how I drive. Empty and 55 or loaded and 70.



As for the temp gauge, it has gotten to the north side of 190 by a tiny bit and that was just before the knocking started. I'm not real sure what the noise was, but it sounded like someone was pounding on the block with a 5lb sledge hammer. I am almost tempted to load the truck up as full as possible this weekend and go pull a grade and try to get the pump to go out. The extended warranty should cover it(heck, even the 100k warranty). And then yell and scream if they don't replace the lift pump too. Or even convince the boss to spring for these upgrades I see in so many posts, Rasp/FASS.

 

[jtisdale]

Will this T-Stat really fix the intermittent problem I am having or is there another underlying problem? Would the T-Stat also fix my poor fuel milage?

More than likely, yes. Although, I dont know exactly what causes it, (I was told it was possibly dead air pockets trapped in the coolant system), others I have talked to with the same problem have changed the thermostats and by doing so, fixed the problem.

Mine did this a few years ago, and later I hooked up a coolant system pressure tester and applied 15lbs. to the system for about 5 minutes to check for an unrelated problem (I thought I had a blown head gasket). After I released the pressure and removed the tester, the problem never came back. Supposedly its relatively common on the ETH's when pulling a long steep grade loaded.



But, I would be very surprised to hear that by changing your thermostat you will see an increase in mileage.

 

[JBlock]

The truck is a company truck. But I might be able to convince them on a set of gauges. I checked for codes tonight, but nothing came up. I'm glad to see they kept the self diagnosis feature on the trucks(same as on my 80's turbo cars).



I have an EGT gauge that I'm pulling out of my Omni. Its a 600-1600 range. Will that work or do I need a full sweep(0-1600)?



The fuel milage is the same no matter how I drive. Empty and 55 or loaded and 70.



As for the temp gauge, it has gotten to the north side of 190 by a tiny bit and that was just before the knocking started. I'm not real sure what the noise was, but it sounded like someone was pounding on the block with a 5lb sledge hammer. I am almost tempted to load the truck up as full as possible this weekend and go pull a grade and try to get the pump to go out. The extended warranty should cover it(heck, even the 100k warranty). And then yell and scream if they don't replace the lift pump too. Or even convince the boss to spring for these upgrades I see in so many posts, Rasp/FASS.

The temperature guage will help, the price is right, the only drw back is you can, cool down with it, you defenanately want to put it post turbo, use a drill with grease and tap with the same. Is it metric thread??