new member

Hi folks. New member of bimmerfest. Got a '97 328i. 133000 mi. with a nagging misfire that mechanics haven't been able to find.

I've even wrote to Goss's Garage. If you ever watch MotorWeek of public TV, he does a segment on there each week. Anyway, Pat writes that I need exhaust tests for CO and HC as the first step in finding the misfire. Sounds resonable to me, but what do I know? I drive BMWs - not fix 'em. But when I take it to a bmw dealer, their techs don't agree with that, or either they don't have the proper diagnostic tools, or they prefer to replace parts until I run out of money! They wanted to put new plugs and coils, and some other stuff..... ($1.500.00) for starters. So I take it back to my local mechanic, who don't have anything but a faults tester and he is currently trying to find the problem. He's bumfundled, but seems determined not to let this little misfire whip him.

Just wonder if any one has had misfire problems and would like to offer advise. I'd appreciate any help you send my way.

O2drive in Georgia

if its misfring REALLY bad....


Reset your car?

Dissconnect the battery for at least 30 mins... then hook it back up.


my old car vanessa was backfiring into the intake and i did this and it ran fine afterwards.. some times these cars just get really confused by themselves

Check the connector, is the one that goes between the coil and the spark plug, they crack from heat and start to "leak" the spark, most people replace all the coil thinking they are bad but coils almost never fail you can buy the connector separately or from junk yard, the symptoms are misfiring or somethimes its feels like the maf failing at idle.

Heres a pick of the coil and connector.

from experience 9 out of 10 times ive dealt with a harsh misfire, not just running a little rough or lack of power it has been an ignition issue I agree with this guy ^ it would be a good idea to verify that all your coils are firing properly, alot of mechanics have tools that will check the spark but they just verify that it has spark, not everyone knows about tools used to measure the actual amount of spark. its a little gadget that allows the spark to jump across a gap which is adjustable and has a scale showing how many volts your plugs are firing with because 10,000 volts and 30,000 volts will both light up your average tester but will make a difference in how the car runs. A couple of other things to look into would be the actual plugs themselves, coils, you might have oil leaking into the plug tubes contaminating the the connection between coil and plug. As far as your mechanic situation I can tell you from experience being in both big dealers and smaller repair shops ALOT of people have a common misconception that all the technicians at the dealer know what their doing more so than an independent shop mechanic, typically what ive seen is that dealership technicians have actually less diagnostic skills that your independent shops, maybe its because they have a huge parts room available to them to try swapping out parts until they get it right or maybe they are just to pampered by working on one type of car only, but most independent shops will do what you said, take the time to find the problem not just throw parts at the thing until its fixed. Not knocking anyone, there are good dealer techs too but thats just my opinion. Good luck!

oh by the way those exhaust test are intended to find traces of excessive unburned fuel aka hydrocarbons or possible water getting burnt in the cylinder. They provide some insight into what's happening in your combustion chamber but nothing I would really use to diagnose such a problem. This is usually done to test for emissions issues and catalytic converter performance.