Dodge Ram pickup truck Cummins
24 valve ISB diesel engine trouble
Dodge Ram 24 Valve Diesel Problems
Troubleshooting and Reported
Tachometer/voltmeter/cruise control problems, check engine
light, engine miss
- Voltmeter reads low, Check Gauges Light and chime on.
Stalls when auto is shifted into drive
- TSB 18-015-00 Rev A - reflash PCM
Rough idle, Missing or stalling
- Idle Speed appears to fluctuate because Tachometer jumps around at
idle - A fluctuation of +/- 50 rpm is normal because the computer periodically
samples the engine speed and then updates the tach.
Stumble or miss at operating speed - The ECT and
IAT sensors must be accurate or the injection timing will be wrong.
- If the engine temp gauge is not reading correctly, the ECT sensor should
- The IAT sensor may be dirty or inaccurate. See the IAT
sensor page for cleaning instructions and typical resistance values.
18-11-99 has been issued to slightly increase the engine power
- If the PCM detects overboost or underboost (usually due to a wastegate
problem), the fuel rate will be reduced resulting in low power. Check
the boost under load - it should peak near 20 psi.
- A fuel vent cap may have been
left on the tank after assembly, and should be removed to prevent
vacuum buildup in the tank. The fuel pump is unable to draw enough
fuel against the vacuum and low power results.
- Turbocharger diagnostic tips -
from the Star Center News
- TSB 18-21-99
provides acceleration charts to check for low power
- Bad or weak lift pump - these
have a nasty reputation for high failure rates. Minimum pump pressure
should be 8 psi under all conditions.
- Bad or dirty IAT (Intake Air Temp) sensor. Dirty is a common problem,
remove and clean the sensor.
- Bad MAP sensor.
- Low boost due to leak or wastegate problem.
- Weak or dead lift pump
Erratic shifting or incorrect shift points
Intermittent high engine idle condition
- Recall 799
- malfunction of the vehicle speed sensor causes sudden acceleration.
Cruise Control speed changes or allows speed
No throttle response on the ISB
- Bad or weak lift pump - these have a
nasty reputation for high failure rates.
- Timing gear 1 tooth off of its setting.
(no PCM error messages generated)
- Bad throttle position sensor
- binding throttle linkage prevents full return to idle position
- sets fault and disables control
Hard to start or No Start
Engine hard to start when hot - Replace bad fuel lift
pump and/or TSB
- Engine hard to start when cold - check Intake
Manifold Heater System
- 00-01 Hard start and/or a no start condition - Service
Action #00-11 replace fuel pump
- 00-01 Ram failure to crank - see service
action #00-01 for fuse revision
- Intake manifold heater relay stuck - replace fried relay and/or heater
- 98-00 Crankshaft position sensor bad - check this especially if the
tach does not always work correctly
Excessive engine noise
foam inserts on the inside of the front fender have
fallen down. If you open the hood and look down into the opening(from
above) at the top back of the fender, there is a large vertical oval
hole(12"X 2") that opens into the door frame. On each side on the truck,
a thick piece of foam should be plugged into the hole. Sometimes they
fall down into the fender compartment. It is difficult to reach, so
enlist help from someone with small arms.
- a few reports of broken valve stems
Buzz from the accelerator pedal when cruise control
Whistling or moaning from heater
core/heater box area - caused by a coolant
supply hose connector
Also described as a growling whirring
sound and if I held the rpm of the engine at 1550...it would stay right
there...sounding like it was coming from somewhere in the front of the
Also described as a howling/warbling
type sound most noticeable with a very light throttle and was most obnoxious
around 2000 rpm..
Headlights alternately brighten and dim after truck is
- Voltmeter jumps up and down - Caused by intake manifold heaters cycling
when engine temp is below 60 degrees.
- Heavy oil or crude oil smell - fumes are blown into cab from crankcase
vent on front of engine
Oil Leak at front of engine
Low oil pressure - pressure gauge drops to 0 and/or warning
Caused by PCM software failing to update the dash
display in a timely manner. TSB
Leaking fuel - line from the filter to the injector pump
788 replace the line from the filter to the injector pump with
Dodge p/n 05013876AA
Leaking fuel, low power, engine miss
Leaking fuel at fuel filter - 98-99 check the fuel
heater connection on top of the filter housing, there have been leaks
reported where the wiring enters the housing.
Power steering pump failure in
More common than it should be
-. If you regularly drive in sub zero (F) weather, you should allow
the PS fluid to warm a bit before driving or install synthetic PS
- Overheating while towing: reports appearing of bad thermostat batch
- replace thermostat : Cummins P/N 3943200
- see Dodge dealer for warranty replacement - no TSB yet
- Oil leak from vacuum pump drive coupling
Last update to this page: March 7, 2008