On my 05, 3500 Dually, I replaced the injectors based on a somewhat reputable, local shop's recommendation.
He said there return flow was 3x the maximum allowed.
I replaced the injectors, with no noticeable improvement in performance.
Truck has 140 +- on the clock.
It's always started no problem, and has decent hight end power, but sure can't pull out in to a tight gap in traffic.
It literally makes not one pound of boost until it hits 1250 RPMs, upon which it gets up and goes pretty well.
It runs a bit hot, and the heat then transfers into the transmission (fully high end rebuilt), which can't keep itself cool when the going gets tough, like on any unlocked hill climb, heaven forbid the stop and go traffic so common on Eisenhower pass.
I took it to another reputable (I think) local shop who has now said it needs a turbo (waste gate issues) as well as a head gasket AND new injectors.
I think he is using the same return flow test, along with the concept that individually shutting off each cylinder should have caused a larger drop in RPMs, he said they were all close in what each one dropped, and took this as a signal that they were all bad. Seems to me this could just as easily mean they are all good?
A third party claims there is no way to diagnose bad injectors on the truck, short of it having troubles starting, when it gets pretty obvious. Apparently the return flow needs very special equipment to be of any validity; simply measuring return flow is not adequate.
I really don't want to replace my brand new injectors based on the same potentially flawed test that may have condemned the original injectors prematurely.
What issues, turbo or other, could prevent the motor from making any boost below 1250 RPMs?
If the wastegate was to blame, it seems it wouldn't suddenly start making boost at 1250 rpm. It makes up to 32 psi @ WOT. Removing the wire to the waste gate actuator changed nothing.
If the turbo is unhealthy, is it worth considering a rebuild? I know a local shop in Denver that rebuilt both my injection pump and my turbo, on a Perkins diesel that runs well 15 years later.
Rail pressures seem to be in parameters.
Lastly how can I know if I really need a head gasket? There's no evidence of cross contamination. The tech said coolant was pressurized. It seems like the radiator cap would blow or there'd by coolant on the overflow; neither are evident. What pressure should the coolant be under? Is this worth buying a test cap for?
It blew an intercooler this spring. Could this be a clue to there being downstream restrictions between it and the motor?
Thanks for reading, and taking the time to help me make sense of this.
Dave
He said there return flow was 3x the maximum allowed.
I replaced the injectors, with no noticeable improvement in performance.
Truck has 140 +- on the clock.
It's always started no problem, and has decent hight end power, but sure can't pull out in to a tight gap in traffic.
It literally makes not one pound of boost until it hits 1250 RPMs, upon which it gets up and goes pretty well.
It runs a bit hot, and the heat then transfers into the transmission (fully high end rebuilt), which can't keep itself cool when the going gets tough, like on any unlocked hill climb, heaven forbid the stop and go traffic so common on Eisenhower pass.
I took it to another reputable (I think) local shop who has now said it needs a turbo (waste gate issues) as well as a head gasket AND new injectors.
I think he is using the same return flow test, along with the concept that individually shutting off each cylinder should have caused a larger drop in RPMs, he said they were all close in what each one dropped, and took this as a signal that they were all bad. Seems to me this could just as easily mean they are all good?
A third party claims there is no way to diagnose bad injectors on the truck, short of it having troubles starting, when it gets pretty obvious. Apparently the return flow needs very special equipment to be of any validity; simply measuring return flow is not adequate.
I really don't want to replace my brand new injectors based on the same potentially flawed test that may have condemned the original injectors prematurely.
What issues, turbo or other, could prevent the motor from making any boost below 1250 RPMs?
If the wastegate was to blame, it seems it wouldn't suddenly start making boost at 1250 rpm. It makes up to 32 psi @ WOT. Removing the wire to the waste gate actuator changed nothing.
If the turbo is unhealthy, is it worth considering a rebuild? I know a local shop in Denver that rebuilt both my injection pump and my turbo, on a Perkins diesel that runs well 15 years later.
Rail pressures seem to be in parameters.
Lastly how can I know if I really need a head gasket? There's no evidence of cross contamination. The tech said coolant was pressurized. It seems like the radiator cap would blow or there'd by coolant on the overflow; neither are evident. What pressure should the coolant be under? Is this worth buying a test cap for?
It blew an intercooler this spring. Could this be a clue to there being downstream restrictions between it and the motor?
Thanks for reading, and taking the time to help me make sense of this.
Dave