Hey guys. I got a rough idle until the car is warmed up and exactly on the 80C mark. It's a 1999 E300 183K miles.

When the car starts in the morning it idles rough, like motor mounts are bad, and is a lot louder than usual. I understand these engines are common for fuel and air leaks. The delivery valve O-rings were replaced about seven or 8 months ago. I don't really know where to look. It does idle rougher in drive, and neutral is slightly better. The engine is still loud, but the vibration is a lot less in the steering wheel and passenger seat than drive.

When I do accelerate, it smoothes out immediately. I'm thinking it's an injector possible? I plan on seafoaming it in the next week to see if it remedies anything. Also, to seafoam it, you would run the seafoam into the prefilter correct? and the output is main filter?

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k