P0343, woe is me
#1
Instructor
Thread Starter
P0343, woe is me
2003 996, 2wd, man trans
here's the run-down, symptoms:
here's the run-down, symptoms:
- when fully warmed-up, driving at 2800-ish RPM at light throttle, there is an intermittent surge or jerk, best described as a 'hiccup' felt
- very intermittent hard starting (crank, no start) after a short hot soak, starts on 2nd or 3rd try. Has stalled two or three times at idle, soon after coming off of a long freeway run (but not immediately after)
- has thrown P0343 code a couple of times, after experiencing the 'hiccup' for an extended period (long freeway drive, smooth road), freeze frame data always shows it at 2840RPM
- one time also recorded misfire codes on the opposite bank at the same time as the P0343
- check engine light does not stay on
Last edited by VFRMike; 04-28-2019 at 05:42 PM. Reason: Cleanup
#3
Rennlist Member
There is a bracket that holds on the sensor that is a known failure point. it can crack and vibrate. Sounds like it with the intermittent failure.
Might want to get cam deviation checked to be sure nothing more going on.
Do you have service history?
Might want to get cam deviation checked to be sure nothing more going on.
Do you have service history?
#5
Instructor
Thread Starter
So is the sensor located at the "front" of the engine (rear of the vehicle)?
When I try to look it up, I find varying descriptions.
If I'm getting a cam position sensor fault, will my deviation readings be accurate?
When I try to look it up, I find varying descriptions.
If I'm getting a cam position sensor fault, will my deviation readings be accurate?
#6
Yes, it's the black connector to the right of the green cam plug. I think the DME is smart enough to detect a short and ignore the bad readings. Do you have odd cam deviation readings?
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#10
I suspect your bank 1 cam sensor is acting up or there's an intermittent short in the wiring. The cam sensor wires go from that connector in the pic to the X59 connector, then to the DME. Not sure why it always happen at the same rpm though.
#11
Instructor
Thread Starter
I'm hoping for it to be the sensor only. Considering how it only acts up when really warmed-up, and driving on a smooth surface...
You'd think if there was a broken wire or connector then rough roads would be a factor.
You'd think if there was a broken wire or connector then rough roads would be a factor.
#12
Instructor
Thread Starter
I was finally able to spend a little time poking around. With the airbox out, I could see the sensor and connector on the driver's side cylinder head. I was able to unplug the connector, and it was "wet" inside. With what, I cannot tell. Next I want to remove the sensor, but haven't figured out how to get a wrench to the allen head bolt holding it in. It seems as if I'll need to support the engine and remove the carrier plate to gain access.
#13
Instructor
Thread Starter
OK, with the help of a stubby 5mm 1/4" drive, I was able to extract the old sensor. It appears to be full of oil. I have a new Bosch sensor going in, we'll see what happens...
#14
Rennlist Member
I'd say Sensor has deteriorated and is wicking oil back to wiring connector head, I had similar on my MB, II went ahead and replaced , Later Crankshaft Sensor went, giving same symptoms, intermittent firing after warmed up. replaced. Runs like new.