Engine surging and check engine light on after Indy repair

[Hit Redline]

OK, took my car in to have the valve cover gaskets replaced. I found some oil on two spark plugs and determined through the forum here that the gaskets were the cause.

So they did the valve cover gaskets, oil change, replaced fuel filter and do an over all inspection.

When I first start up the car I feel this surging, only when in gear. Goes away when in neutral and don't feel it under acceleration. Just today it seems worse and the check engine light came on.

I thought maybe they didn't put the ground on the coil or a loose coil. So opened it up and everything looks as it should. Grounds connected and coils are in tight.

My guess is that the coils weren't put back into the same cylinders and are causing a misfire. What do you guys think?

I will be going into the indy shop tomorrow but maybe I could get some insight on what this might be.

[Hit Redline]

Just dropped off and waiting to here back.

[Hit Redline]

Turns out it was a bad coil. She runs nice and smooth now.

[Weasel]

I had a coil go out on me about a week ago too...missfires are pretty tell tals as the light usually flashes during an active missfire.

Then to be mean to me again, my alternator went out 2 days ago... expensive assed water cooled son-bitch!

[Max Gunner]

Originally Posted by Weasel

I had a coil go out on me about a week ago too...missfires are pretty tell tals as the light usually flashes during an active missfire.

Then to be mean to me again, my alternator went out 2 days ago... expensive assed water cooled son-bitch!

Does it make sense this would only cause a noticeable problem when in gear? It seems to me it would be noticeable even at idle, but maybe I'm thinking about it wrong.

MG

[Weasel]

The miss will barely be audible in neutral, but will be tons more noticable and felt when under load, especially at idle and just over.

But as I mentioned, the only reason the check engine light ever flashes is when it sees an active missfire.

[killcrap]

Originally Posted by Weasel

The miss will barely be audible in neutral, but will be tons more noticable and felt when under load, especially at idle and just over.

But as I mentioned, the only reason the check engine light ever flashes is when it sees an active missfire.

when the check engine lamp is flashing, that is an indication that the catalyst is being damaged. not active misfire.

[Hit Redline]

My check engine light was just solid, no flashing.

[Weasel]

Originally Posted by killcrap

when the check engine lamp is flashing, that is an indication that the catalyst is being damaged. not active misfire.

Actually a mix of both of our answers... It is technically when a severe level of missfire that would be catalyst damaging is detected, then BMW actually turns off the injector to that cylinder after a while to prevent catalyst damage.

[killcrap]

Originally Posted by Weasel

Actually a mix of both of our answers... It is technically when a severe level of missfire that would be catalyst damaging is detected, then BMW actually turns off the injector to that cylinder after a while to prevent catalyst damage.

Nope just catalyst damaging. It's an obd2 requirement for engine management. Seen plenty of "active misfires" check engine lamp didn't flash.