Issue, need input

[runner1]

Cold start car fires right up a bit rich and idles great. After letting it warm a few minutes it gets put in reverse. At that point it’s starts a shake in the seat and starts sounding rough. Backing up she shoulds deep in tone with knocking sound (not fuel pump). I can audibly hear the valve train amd a knock. Into drive I can feel a vibration in the car. This continues for about 3-4 minutes of driving then she’s back to normal. I’ve got fresh fuel and still an issue. Could a bad plug or coil cause all this nonsense? Can a bad plug/coil clear up as the car gets hot?

 

[nhcowboy28]

Have you modded in any way?

 

[runner1]

JB4 with denso about 3-4K ago. It was really bad a couple days ago but seems better, but not right.. The knock is concerning but it goes away so to me it’s no bearing/rod.

 

[nhcowboy28]

Data logged it yet and had terry look?

 

[runner1]

Looks fine once warmed up log looks fine through Wills bot. Only when first few Minutes driving when cold

 

[nhcowboy28]

U know the next steps.

pull the JB4 off, go to stock plugs and see if it keeps happening.

 

[runner1]

Yup. On it tonight. I’ll check back after.

 

[runner1]

Passenger side plug by firewall not overly tight. I put in a new set of plugs, everything seems to be as it should be