Yanivic

Hello All,

My car (03 A6 with 3.0) is having Idling problems for about couple of weeks. It had a code P0300 and P0305- Intermittent misfire in Cyl-5; I replaced the plug and Coil and it still has the same code.

The Error Light came on after 100 miles or so and the only thing it exhibits is, it hunts to find the right Idle by about 100 RPMs, when I give a little gas (in neutral) and has slight vibration when I start it (cold engine) for a few seconds...

The car has 40k miles but out of warranty, wondering if it's a bad Injector or anything else. I do not have VAG, but found a Generic cable and used Shareware to pull the Code.

anyone else have had similar problem; if so, what was the diagnosis?

Thanks in advance!!!

Aarononymous

might want to see if coolant if coolant is getting in there.....

WOWDee

Did you replace the plugs? What did old ones look like?

Yanivic

The car had 40k service @ 37k or so. only the plug in cyl-5 looks like it had a little deposits around the electrode, but it doesn't look like a fouled plug; its sort of white to tan colored deposit (just a little coat).

the other plugs practically looked clean with out any deposits. I am not sure why its just the cyl-5 even after replacing plug and coil.

I did add seafoam to a tankful of gas. I had the code after that tank of Gas, it's possibly a coincidence. The Idle wavers by around 100 RPMs and it does for longer duration when I switch the A/C on or off.

Thank you both...

WOWDee

before i spent alot of $ on anything else. Clear the code and see is you get it back.

Yanivic

... but I am curious on to why only cylinder #5 has this problem and not others.

I tried to read the blocks using shareware and the MAF reads fine and it even peaked at 179gm/sec which I think would a average number for a 3.0 engine.
The injector run time is weird though, it actually is decreasing in time interval when ever the idle wavers.

I shall try to replace the plugs and also the remaining coil packs.

Thanks.

Yanivic

no code yet, but the idle wavers when I give it a little gas or switch on the A/C. it does that for close to a min, jumping out and down by around 100 or so rpms.