Where to start?
I experienced symptoms similar to yours about 4 months ago. Unfortunately, the rough idling for me was due to a faulty #6 fuel injector and a leaking head gasket near the #1 cylinder. Both replaced. Additionally, I had quite a bit of surging at idle. The vehicle would consistently surge between 500-800 rpms. This lead to the diagnosis of the faulty IP.
1. Does the rough idle calm down as the engine temp rises?
2. Is the car "hammering" consistently?
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