Gearheadjarrod

Hey guys I'm having a problem with my a8 the check engine light is on evap leak but I have a misefire at idle and a flashing check engine light while driving but only flashes when getting on it.
I installed new plugs but have no idea what's up

2001 S8

Could be a multitude of things. Since you did the plugs, my next step would be ignition coils.

Good luck

jfrahm

Yeah I have heard you can get an inductive timing light to flash by holding the pickup near a COP coil. If so then a bad coil (or bad coil wiring) might be detected this way. I have not tried it. I have 2 spare coils so naturally I never have any coil problems :-)

Y888

I have 8 good coils off my car(oem hitachi) in case you you need them and they fit,i am open to offers.

icrashcars

Pull the codes. If it's a misfire it will tell which cylinder(s).

Then swap the coilpacks around. (label them)
Reset codes.
See if the misfire codes follow the coilpacks.
If they do, then you will know which coilpacks to replace.

If they don't it could be your plugs, or wiring.

Ok22

Have you read the code to see where the misfire is? Replacing parts is fine if you are due anyway, but throwing parts at a problem is not the best way to go. Flashing check engine light means that your engine is currently misfiring. If its only when you are "getting on it", that's under load or high RPM.
If you can isolate it to a particular cylinder, then you can look at that one. Air-fuel-spark... Swap a coil and see if the problem moves.
If it's random across all cylinders I'd look for a vacuum leak first, then check for good fuel flow.
One side of the engine? probably related to timing - belt or cam adjusters. Could still be lots of other things.

spitanddirt

How many miles does your car have? I can't say for certainty when my coils started to drop out, but they are good for about 180-200k miles. Don't buy aftermarket China coils! They work in a pinch but they start failing after about 30k miles. Ask me how I know this......


+1 for icrashcars instructions for how to isolate a bad coil pack.

Gearheadjarrod

Only one code is present that's the evap leak small
no codes for misfire.
Plugs are new Ngk old plugs were auto light.
can coils go bad with out a code?

Gearheadjarrod

My A8 has 150000 miles.

Y888

I went from oem bosch to ngk platinum laser something and my mpg went from 16 to 13.
I am going to go back to bosch soon when i do tbelt.