My 8 was in storage while I was deployed, come back, and it is WAY down on power and not running like normal, it's making some kind of sputtering/chugging noise at idle and spitting white smoke like it's been seafoam'd. So I sucked in some actual seafoam then changed the plugs and there's no effect. It's throwing constant P0300 and P0301 codes (random misfire and front rotor misfire) with occasional P0113 and P0171 codes. When I drove it around the block 6th gear could even hold it at speed. After the drive it would start again... it sounded like one rotor was firing and running then the other would drag it to a stop... Then this acrid white smoke started wafting from under the hood! I'm a little freaked out and at a loss for what to do. Please help!

 

Have you verified your intake tract is clear? Any chance of rodents? Why did you seafoam it? Old gas?

 

I seafoam'd it because I thought carbon buildup might be a culprit... I had a similar power loss symptom before (minus smoke) and the dealer told me it was "partial flooding," which I'm not sure is a real thing, but I thought seafoam might help with. It didn't.

 

What about rodents and gas?

 

It probably has old gas, but do you really think that could have such a dramatic effect? Nothing was in the intake tract, I had to pull the air box as part of setting up seafoam.

 

Heck yes bad gas can gum up and cause major issues. How long were you deployed?

 

It was a 6-month stretch. I don't think that's it, though, the gas had Sta-Bil in it and that doesn't explain the smoke.

 

Nah, if it was only 6 months and you had stabil in it then that is probably not it. If you changed the plugs then my only other advice would be too clean the MAF. I don't see coils going bad just sitting but how many miles were on them when you parked it?

 

How is your coolant level?
Was the storage temp controlled. Did it freeze while you where gone?