bfreehill2

Hello all,
so I have a 98 A4 2.8 30V 5spd 145k that currently has me stumped.
Out of nowhere it began misfiring in traffic, limped it home and it seemed to get worse.
I pulled a few OBD misfire codes but nothing else.

With VAG-Com I observed misfires at idle on plug one,
above 3000 rpm the misfire jumps around to other plugs.

I replaced the plugs, coilpack, cleaned the throttle body and MAS, new fuel filter, and did a compression check.

Plugs wires are next on my list (they look fine but have not tested them yet)

thanks for any input...

Prospeeder

You didnt do plug wires? Thats your problem. You cant just look at them. thats part of a tune up, replace them. None of the plug wire boots had oil on them when you pulled them out like the valve covers leaking?

A Serious vacuum or air leak, timing being off, belt or chains off, and a bad engine controller are possible random missfire causes.