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DISCUSSION => Engine management => Topic started by: Zugunruhe on September 16, 2007, 02:03:09 PM

Title: Faulty O2 sensor?
Post by: Zugunruhe on September 16, 2007, 02:03:09 PM
Hey all,

I've been slowly refurbishing a neglected 4 door 318i, purchased in May.  Most recently, yesterday, put in a new timing chain tensioner which, at first, stalled the car.  Then, slight ticking disappeared and engine sounded great.  

Next, I disconnected the battery, removed old, very nasty looking o2 sensor.  I replaced this with a brand new Bosch unit.   Then reconnected battery.  Car choked and died on start up.  Tried to drive off, but coming to a stop a few blocks from my house, disengaging the clutch (with accompanying drop in RPMs), caused engine to stall and Check Engine Light (CEN) to come on.  Car not happy.  At all.

Today, idled car to get up to operating temperature (car has new thermostat), put in 91 Chevron, and drove 30 minutes on highway, at high RPMs, thinking I could get the system happy.  No luck.  I've checked the connections and everything looks fine.  

Do I have a faulty, brand new o2 sensor?  Can a new o2 sensor throw something else out of whack???

- Andrew

Oh, if anyone in the Bay Area wants a '86 325es that runs great, but was tagged last year, let me know.  DMV took my money for registration and then told me I need to pay for salvage title and lights testing.  Mechanically, very, very sound.  Another 100k on the driveline would be my guess.  If you want to pick it up, let me know.
Title: Faulty O2 sensor?
Post by: silverblades181 on September 16, 2007, 06:17:40 PM
Well I don't know if you touched the intake rubber boot while working but check the small hose that's under the big intake boot. This sounds an aweful lot like when I had disconnected it by mistake while changing the air filter.
Title: Lower air intake boot was the problem - thanks
Post by: Zugunruhe on September 16, 2007, 07:06:32 PM
Quote from: silverblades181;33818
Well I don't know if you touched the intake rubber boot while working but check the small hose that's under the big intake boot. This sounds an aweful lot like when I had disconnected it by mistake while changing the air filter.


Silver:

Well, you are a deserved advanced member.  This was the problem, precisely.  The boot is very worn and I checked the filter yesterday, so it must have jostled loose.  Thanks for keeping me from falling down a rabbit hole and making my wife  (landscape gardener) drive the M3 to work tomorrow...

- Andrew
Title: Faulty O2 sensor?
Post by: gearheadE30 on September 16, 2007, 08:12:17 PM
keep it 3 years, and I'll take that eta off your hands... ;)
Title: Don't dis the ETA
Post by: Zugunruhe on September 16, 2007, 09:47:20 PM
Quote from: gearheadE30;33824
keep it 3 years, and I'll take that eta off your hands... ;)


Gearhead:

The ES has treated me very, very well.  While nothing like my '89 M3, or even the 318 in terms of chirpy, high-end fun, Bessie was good out of the gate and very, very quiet at 90.  Averaged 36 highway mpg to boot, so it is a sad goodbye.

- Andrew
Title: Faulty O2 sensor?
Post by: silverblades181 on September 17, 2007, 06:16:10 PM
Glad I could help. I had to drive 1h30 in traffic with that problem...going to work before I took a look and figured out what it was...very annoying lol. I tought I had more serious problems aswell.

BTW, got pics of the M3? :D