Jeep Cherokee Power Loss Points to Cylinder Issues

Had similar issues with a 2004 Jeep Grand Cherokee CRD. Initial symptoms matched yours, poor fuel economy, power loss, and engine warning light. The root cause turned out to be a failing fuel injector, which was creating uneven cylinder pressure. The faulty injector had caused carbon buildup in the intake manifold and damaged the turbocharger seals. The real problem emerged when the failing injector started leaking fuel into the cylinder, washing away oil from cylinder walls. This required a complete fuel system inspection and cleaning. The repair involved replacing all fuel injectors as a set since mixing old and new injectors can cause pressure imbalances. This was definitely a serious repair that needed immediate attention to prevent engine damage. The symptoms you describe align closely with fuel delivery problems rather than piston rings or head gasket issues. A compression test would rule out mechanical problems, but recommend having the fuel system diagnosed first, particularly the injectors and high-pressure fuel pump. Would suggest getting diagnostic readings for fuel rail pressure and injector timing. These measurements will quickly show if the fuel system is the culprit before exploring more invasive mechanical checks.

Thanks for sharing your experience. Your situation sounds very similar to what I encountered with my Cherokee last year. The fuel injector diagnosis makes a lot of sense, especially considering I also had that distinct engine knocking sound when accelerating. After getting it fixed, the engine performance improved significantly. I am curious about the cost of your repair, particularly the full injector set replacement. Did any other issues surface in the months following the repair? The crankshaft in my case needed additional work a few months later, though that might have been unrelated.

After taking it to the mechanic for a proper diagnosis, they confirmed the cylinder pressure fluctuation was caused by the failing injector system, just as suspected. The repairs were completely covered under warranty since it was traced back to a previous repair job that wasnt done properly. The timing belt had been incorrectly tensioned, which led to the engine knocking and eventual injector problems. The good news is that since the complete injector set replacement six months ago, the engine has been running perfectly with no issues. The intake manifold was thoroughly cleaned during the service, and they also checked the camshaft while the system was apart. Having this done at no cost was fortunate, as a full injector set replacement typically runs quite expensive. Unlike your situation, we didnt experience any crankshaft complications afterward. The head gasket was also inspected during the repair and showed no signs of wear, which was a relief. The fuel economy is now back to normal, and the engine runs smoothly without any of the previous symptoms.

The mechanic visit turned out better than expected. A thorough diagnostic test revealed worn piston rings were not the culprit, it was actually a clogged fuel injector causing the power loss. The turbocharger was also showing early signs of wear due to the fuel system issues. The repair took about 3 days total. They cleaned the entire fuel system, replaced two injectors, and performed a full inspection of the crankshaft and related components. Cost came to 1200 Euro for parts and labor, which included a comprehensive engine diagnostic. Since the repair, fuel economy has improved by about 25% and the engine knocking completely disappeared. The check engine light hasnt returned, and the power delivery feels much smoother, especially during acceleration. It was worth getting a second opinion and finding a mechanic who took the time to properly diagnose the real issue.