05 Jeep Liberty Diesel-Under Powered

Approximately three weeks ago, my liberty diesel with 163,000 began to run as though it was down a cylinder. After checking a readout from my scan gauge, It said cyl 3 had a misfire so it was assumed that injector 3 was bad and replaced. To no avail, the jeep was brought to a local dealer who flashed the computer and attempted to calibrate new injector. Since the jeep did not run any better, it was towed from dealer to my home.

My question is could a bad crankshaft sensor make it act as though it was down a cylinder, supposedly had air leaks in fuel system and a bad map sensor. It does not appear that any rocker arms are broken. Or did it jump time? The dealer’s printout showed all codes that ever came up while driving the jeep over the past 7 years.

Are there any auto parts stores that rent code scanners/flashers that will work on Liberty Diesel in Connecticut? Any suggestions would be appreciated. Thanks.

Have the valves been adjusted? Has the compression been tested? Has the fuel filter been replaced?

If the injector was replaced but showed no improvement on cylinder three, then a compression test is in order. Afterall, diesel engines require just fuel and air in each cylinder.


Other than agreeing about compression, I wonder why the dealer didn’t consider a cylinder being down; or maybe others on the way down too.

Isn’t this model turbocharged? If it’s dropping a cylinder, or plural, due to miles and wear then maybe the turbocharger is suffering also.

I would think a real compression test with a gauge, done on all the cylinders, would be the FIRST diagnostic test…If compression checks out, then it’s off to the diesel lab with the injection pump…