Loss of power and runs rough

[dmax_lineman]

I bought a 04.5 Dmax about 5 months ago, sense then I've had very few problems with it. The problems consist of pulling to the right due to the idler and pitman arms and upper ball joint dismembering itself from control arm. Until recently, about a month ago i noticed that it doesn't pick up the way it when I first got it. I have replaced the fuel filter, that did no justice. So I assumed it had to be an injector problem but the truck is new to me, so I called the closest dealership and had them run the vin# to make sure all recalls had been taken care of on this particular truck: and the had. So the injectors were replaced due to the recall about 10 months prior to my purchasing it. Now I'm stumped, this is my first diesel so this is all new to me. I'm pretty mechanically inclined so doing the work myself isn't a problem, knowing where to go from here is.


I'm running 4in Banks exhaust
Banks cold air and intercooler
Banks sixgun programmer
32in Mckey Thompson MTZ tires

My buddy put his basic code reader up to it and dispite the check engine light not being on it did through a few codes out. One was for coolant temp, one was a misfire in cylendar six, one just said comp.( which I just figured was due to the programmer ), and the last on just said EGR with no other discription.

Does anyone have any suggestions? After all the other stuff Ive done to it I have just about depleted my savings, so cheapest but most efficient way possible.

[Mark Rinker]

Welcome aboard. I am pretty sure that you'll find this to be the best truck you've ever owned.

Unless you are experiencing knocking and/or white smoke visible in your exhaust (either at idle or under acceleration), or black smoke under acceleration (overfuel condition, lacking enough boost to burn fuel present) I'd say you are looking at a simple fuel or air supply problem. Since you've replaced the fuel filter, how about the air filter? Any chance of restriction or temporary collapsing of an air inlet tube during high demand/acceleration?

The codes could be misleading since they may be from BEFORE the injectors were replaced. I'd take note of them, then clear them all and start again.

If you are NOT seeing white or black exhaust smoke under any of the above conditions, no fuel rattle, and no oil dilution/making oil at the dipstick...

Q1: Is it possible that there is a problem with the power adder, and you're not getting the additional fuel rate that you had grown used to?
Q2: Could you have a leak at one of your aftermarket intercooler connections, and be leaking charge (boost) air?


Keep checking in as you troubleshoot. I think you'll find the root cause of this one to be a simple one.

[dmax_lineman]

Thank you for your prompt response.

I check the connection at the intercooler and found them to be secure and leak free. There is no sign of any color smoke coming from the exhaust, and when the problem first occurred I was in the middle of passing about five diesel trucks and the sixgun programmer was turned up to 6. The check engine light did appear as well as the loss of power. I pull over, turned the truck off and reset the programmer by unplugging it for about 30 sec. and plugged it back in, and the truck seemed to be back to normal, for a couple weeks anyways. Then began the gradual depletion of everything. Although the check engine light went off I still borrowed the OBDll code reader and those codes popped up so I cleared them and waited a few days to read it again. The codes came back and have been there ever sense. Any and all suggestion or ideas are appreciated and welcome. Thank you for your time.

[DmaxMaverick]

If the EGR isn't blocked and disabled, it's probably fouled. The excess soot can also foul the vane position servo. Running the Six Gun on level 6 is not a good idea, especially at highway speeds or with a load. If your tranny is stock, you'll be shopping for new very soon. Level 6 also expedites EGR and servo fouling, moreso than lower levels.

[dmax_lineman]

Thanks for the info about the six gun. I'm not really too fond of not knowing or being able to monitor or even see the parameters. It didn't come with gauges or a digital screen, just the component and a dial. I never really turned it up past 4 except at night while passing due to the difficulty judging how far away the car in the other lane is.

Now, that being said, my next hypothesis is the head gasket could possibly be blown or maybe leaking by. My reason for this conclusion is: while going over the inlet and outlet to the intercooler I noticed that the coolant hoes on the driver side was slightly collapsed and the coolant level was a little low(less than 2qrts.) So it made me wounder where it went. Upon checking the oil level (which was full), it seemed like it didn't want to stay on the dipstick, and the oil pressure seems to be a little high.

Any thoughts? And what is normal operating oil pressure? Isn't there supposed to be discolored exhaust if the head gasket is blown?

[DmaxMaverick]

That's a risky proposition, a power programmer and no gages.

Head gasket? Difficult to say. Any one of the symptoms you list don't indicate that, in themselves. A collapsed coolant hose is more likely a failed recovery tank cap. "Slightly" collapsed may be normal. Coolant loss can also be caused by a bad cap. All of it depends on how much loss, and under what conditions. If it's very slight, you may not notice foggy exhaust (steam), or the associated odor. Start the engine after cooling overnight, and check the upper coolant hose after a couple minutes idling (as soon as the temp gage begins to move, but not hot). If it gets very hard, you have a bad gasket. If it seems normal (neutral pressure), then it's less likely.

Oil pressure depends on other factors. Cold idle pressure should be 60-80 PSI. Hot idle should be 20-40. It can be higher/lower, depending on the oil brand, grade, and other conditions. If you have coolant in the oil, it will usually have no trouble sticking to the dipstick, and will be cloudy or milky. To confirm, drain some oil after the engine cools overnight. Most of the water, or water saturated oil, will settle to the drain.