Avantime Diesel Jerking Acceleration

Your symptoms do indeed suggest a potential issue with the intake manifold. The jerking, reduced power, rough running, and exhaust smell are all classic signs. It reminds me of when my old Saab 9-5 had a similar problem; turned out the intake manifold gasket had failed. Consider it like a garden hose with a split – you lose pressure and the engine doesn't get what it needs efficiently. Are you noticing any hissing sounds or unusual vibrations?

No hissing sounds that I've noticed, but the vibrations do seem a bit worse than usual. You mentioned your Saab – was it also a diesel, and did the error code point directly to the intake manifold?

My Saab was a petrol engine, actually. The error code wasn't explicitly "intake manifold," but rather indicated a general misfire and lean running condition. Given your diesel engine and the combination of symptoms, a leaking intake manifold due to scorching is a strong possibility. It’s like a cracked pipe in your house; small at first, but it escalates. I strongly recommend getting it checked by a workshop. They can perform a smoke test to confirm any leaks.

I took it to the workshop, and you were right. The intake manifold was defective due to scorching. The repair cost me 1180€.