VW Jetta Diesel Performance Issues & Rough Running Fix

Had similar issues with my 2009 VW Passat TDI. The symptoms match what I experienced, engine misfire, rough running, and power loss. After thorough diagnostics, it turned out to be a significant intake manifold gasket leak combined with compromised manifold pressure. The scorching around the gasket area indicated the leak had been present for some time, affecting engine performance substantially. The repair involved replacing the entire intake manifold assembly and gaskets, as the original manifold showed warping from heat exposure. Without proper repair, these symptoms typically worsen and can lead to more severe engine damage. The job required specialized diagnostic equipment to confirm manifold pressure readings and identify leak points. For your Jetta, considering the mileage and symptoms, its worth getting a proper pressure test done. The manifold issues on these engines are known to develop around this mileage range. This was definitely a serious repair that needed immediate attention, as continued operation with a leaking manifold risks further engine complications. Would recommend having it checked by a shop specializing in VW diesel engines, as proper diagnosis is crucial for these specific engine configurations.

Thanks for your detailed reply about the manifold issues. My situation sounds identical, the vacuum leak symptoms and check engine warnings really match up. These VW diesels seem prone to intake problems around this mileage. Just curious, what did the total repair cost you and have you had any similar engine performance problems since getting it fixed? I want to budget properly and make sure I fix it right the first time.

Just wanted to follow up, after seeing the mechanic, they confirmed it was indeed a defective intake manifold like I suspected. The repair ran 1180€ to fix the leaking manifold that showed serious scorching damage. The good news is my Passat has been running perfectly since the repair two months ago. The air intake system now maintains proper manifold pressure, and all those engine misfire symptoms completely disappeared. No more rough running, stalling, or check engine warnings. The repair was definitely worth every euro since these vacuum leaks can cause major engine damage if left unchecked. Looking back, catching the failing gasket leak early probably prevented more expensive issues down the road. If your symptoms match what I experienced, getting it fixed properly now will save you from bigger headaches later.

I finally got my Jetta fixed last week and wanted to update everyone. The mechanic found heavy damage to the intake manifold, exactly matching what was described. The repair came to 1250€ including new gaskets and pressure testing. The air intake system needed a complete overhaul, as the vacuum leak had caused some related issues. The check engine light disappeared right after the repair. The engine now runs smooth with no jerking or stalling. Full power is back and that nasty exhaust smell is gone. The shop showed me the old manifold, the gasket leak had created visible scorching around the edges. Catching this before it caused major engine damage was definitely the right call. Thanks for helping point me in the right direction with the diagnosis.