Jimny Diesel Misfire Points to Intake Manifold Issues

Had the exact same issue with my 2003 Vitara diesel last year. I have some experience working on cars but this one required professional help. The symptoms you describe match my experience perfectly, the engine performance issues, check engine light, and that distinctive diesel smell all point to a manifold sensor problem. In my case, it turned out to be a serious gasket leak in the intake manifold caused by heat damage (scorching). Initially tried checking the air intake system myself but quickly realized it needed workshop expertise. The repair involved replacing the entire intake manifold assembly along with all gaskets and sensors. Total cost was 1180€ including parts and labor. Before offering more specific advice, could you share: Current mileage on your Jimny? How long have you noticed these symptoms? Have you had any recent engine work done? Are there any additional warning lights besides the check engine light? This information would help determine if your issue is similar to what I experienced. The repair resolved all my problems and the engine has been running smoothly since.

Thanks for your thorough reply. My Jimny has 22944 KM and just had its annual service last month. The issues started about 2 weeks ago. The manifold pressure seems inconsistent based on the rough idle. I noticed the check engine light first, then the performance issues developed gradually. No other warning lights are active. The symptoms match what you described with your Vitara. Based on your feedback, I will have a professional check the intake manifold and gaskets. The diesel smell during acceleration is quite strong, which reinforces the likelihood of a vacuum leak somewhere in the system.

Thanks for the additional details. The relatively low mileage on your Jimny actually makes this manifold issue more interesting. After fixing my Vitara, I learned that these manifold problems can occur regardless of mileage, often due to heat cycling and gasket deterioration. The gradual onset of symptoms matches my experience perfectly. My manifold sensor readings were also erratic before the repair, showing inconsistent manifold pressure values. The strong diesel smell during acceleration is a telltale sign, the exhaust gases are likely escaping through failed gasket seals in the intake manifold assembly. With similar symptoms developing over just 2 weeks, getting it checked soon is wise. In my case, delaying the repair led to increased fuel consumption and eventually affected other engine components. The total repair cost might be lower for your Jimny since you caught it earlier, mine had developed additional issues by the time I got it fixed. One tip: when you take it to the workshop, ask them to check the manifold sensor connections too. In some cases, the wiring can be damaged by the excess heat from the leaking exhaust gases. The check engine light often triggers due to faulty sensor readings before the mechanical problems become severe.

You know what, I really appreciate all this detailed feedback about the manifold issues. The suggestion about checking the sensor connections makes a lot of sense, especially since the check engine light was my first warning sign. The gasket leak explanation fits perfectly with what my Jimny is doing. Based on the strong diesel smell and rough running, I suspect my vacuum leak might be pretty significant. The manifold pressure problems are getting more noticeable each day, so I will not delay getting it checked out. I have already called a workshop and booked it in for next week. They mentioned they will do a full diagnostic of the intake manifold system and check all related sensors. Given the relatively low mileage on my Jimny, I am hoping the repair costs might be lower than the 1180€ you paid, since I caught it early. Thanks again for sharing your experience. It helped confirm my suspicions about the manifold being the root cause rather than just chasing other potential issues first.