Oh Goodie, Another misfire thread.....

[bmrboi2]

I am going nuts.

It all started with a longer than usual start 2 months ago. Great, I need to order some ignition coils....do I? No. I've pumped about a gallon of Seafoam and Lucas cleaner through this thing in conjunction with my daily fill ups.

I have been getting a 29F4 and 29F5 for the Catalyst Conversion 1 & 2 for almost 2 years.....Very seldom and random.

The Truck performed just fine until a week ago.
It had a rough start that evening leaving work and a noticeable skip in the idle.
Cylinder 4 misfire 29D0. I bought a coil from O'reilly @ 68 bucks (ouch) I get home, pull it apart and the cylinder for the plug has about an inch of oil in it. (Great valve cover gasket. its getting done next week) I remove the spark plug and clean the piss out of the plug and coil. I install the plug and go to install the new coil (Just in case) It wouldn't slide and seat properly. What the heck. I push the old one on and She fires right up and is running like a raped ape. I shoot down the street and return the coil as it didnt fit.

Next morning, Rough Start Spitting and sputtering and the idle smooths out. Slight hesitation off the line. No real issues otherwise. Drive home, hesitation and a slight idle hiccup at random.

Monday, I decide to make sure that all of the plugs aren't swimming in oil. What should have taken 30 minutes took 4 hours as the rubber grommet from my plug socket was still on the sparkplug. Button it back up, all is well, truck is fine.

Tuesday spit and sputter start. GRRRRR. 29CE and 29D0 Cylinders 2 & 4 and a Vanos intake code. The Catalytic Codes are back. Driving home was awful as the reduced performance was further enhanced buy having the AC on. Idle hiccups as well.

I am basically convinced its this damn #4 coil. I order 6 new Bosch Coils and they arrived yesterday.

Last night I installed them all, this morning same rough start. HOWEVER the idle is smooth. Slight hesitation off the line and slight hesitation until I get on the expressway. I get off the expressway and everything is seemingly FINE. YAY She's back...I resume my normal driving style on the road to my office as it has some twisties....sport button and in D/S. It was perfect...

I come to the stoplight and sure enough there is that damn engine miss at idle again...

I am going to clean the Vanos cylinders before I replace them.

I'm not great with things like this guys, I can hunt down issues with the suspension and otherwise replace parts based off what the vehicle needs. When I search, Im getting 10000 issues for what it could be. I don't know what else it could be. HEEEEEEELLLLLLPPPPP! Right now we are down to two vehicles! (The F-150 hasnt even been built yet)

[ard]

1. Your "truck" was just fine until a week ago? Yet it has been throwing codes for TWO YEARS?!? It has not been fine. You have had a subcritical issue for years, likely running the 'truck' on the edge of a fault condition, but occasionally beyond hence the codes.

2. I'd suspect an air leak or a vanos solenoid issue. Just a WAG. These are things that can persist for years, cause the DME to run up against the limits- trip occasional cat codes.

3. You also need to fix the oil leaks.

Have you looked at the long and short term fuel trims? Try to understand where the engine is operating??

[bmrboi2]

1.yeah it's been fine. No signs of any sort of failure. I take very good care of my vehicles and address issues when they arise. The first cat codes would come in 6-8 month intervals. Mind you I have put almost 60k on the TRUCK in 2 years. It was so random that it didn't warrant my going nuts searching down some random blip.
2. Thank you....I'll start smoke testing after I get back from the coast.

3. Yeah they get addressed in a timely fashion when I notice them.

Thanks ard.

[ard]

Look into ST/LT fuel trims... How to run a vanos test. They are a step beyond pulling OBD codes, but worth looking into.

Sluggish vanos can run to very rich running, which will cause fuel shear in the oil, increased wear, but otherwise no 'issues'. Owners think there car is 'running great'. They wash it every week, life is good. Maybe once in a while they get a cat code when the cats cant keep up witjh the hydrocarbon load. It looks to you like an odd, occasional "blip'...but it might MIGHT be a underlying continuing condition.

It isnt a sign of 'bad owner' if you dont see this. I went two years chasing an odd rich condition on my S62. Just bringing it up as an POSSIBILITY.

[bmrboi2]

It was the Vanos. I cleaned them as a quick test. 1000% Difference. Ordered 2 Today.

[ard]

Huh. What did you order??? The "VANOS" is a pretty complex and expensive assembly...just the solenoids? Sensors?

Part numbers may help future travelers....

[bmrboi2]

Part Number: W0133-1821156 New Vanos Solenoids From Parts Geek

$149 each. Genuine BMW Used a free shipping and 15% coupon.

[ard]

I believe PartsGeek sells a brand named "Genuine".

So when they say 'genuine' it doesn't mean "OE BMW' nor 'genuine BMW part'.

FWIW.

[bmrboi2]

SMDH