Misfire codes after 3SI Manifold Swap

Kerbouchard · 03-31-2019, 01:50 PM

Hi All,

Just completed the 3SI manifold swap on my N52 128i. Everything seemed really straight forward on the job, I labeled all connectors, everything "clicked" nicely upon re-install.

I also replaced the eccentric shaft sensor seal and the intake resonator while I was in there.

Note that I have not yet tuned the car (Bimmer Performance Center, etc.), so the ECM doesn't "know" there's a new manifold there yet. I know the tune is required to pick up the big HP bump, but I was under the understanding that the car would drive fine without a tune.

Upon 1st startup, everything ran clean with no issues, no codes. drove slowly around the block, no problems. Took off from a light at 3/4 throttle and got "service engine soon" and a lopey idle. Nursed it back home, turned it off.

When I turned it back on, the "service engine soon" light had gone off, but code reader showed P0301, P0302 and P0300 codes in "pending".

Is there a common connector that I should check first to diagnose this, or do I just need to get the tune installed before driving it again?

I'm hesitant to start taking the cowling and engine cover back off to double check connections in case it's just a software issue.

Thoughts?

Thank you!

6ixSpd · 03-31-2019, 02:24 PM

Those misfire codes are unrelated to the missing 3SI software.

Kerbouchard · 03-31-2019, 02:58 PM

Thanks for the quick reply! Based on another thread, I cleaned the oil off the eccentric shaft sensor connector using alcohol and a q-tip. Seems to have solved it? Go figure.

nsjames · 03-31-2019, 08:22 PM

if you've got oil in the connector, chances are the ESS needs replaced.
that's your early warning that it's failed.
eventually the oil will sop it reading properly and you will have starting and running issues.

at the very least check it again soon and see if there's more oil. It's been known to work it's way all the way up the wiring jacket and then bone the DME as well.

bluewater328 · 04-02-2019, 01:28 PM

Yeah, I did a re-read of his first post. While he replaced the ESS seal, he didn't replace the actual ESS.

Hopefully the cleaning helps, and I suppose you could continue to do that till it actually dies, but that's going to be a problem as it's pulling oil into the sensor. Unfortunately, if it keeps coming back, that's going to mean removing the valve cover again to replace.

nsjames · 04-02-2019, 05:54 PM

when mine was failing the car simply didn't start below 40F

no idea why it was so buggered about colder weather, but that's what tipped me off.

popped the connector, oil in it.
cleaned it, was better, but then started to get worse on the starting front.
Obviously once oil gets in there, it's a crap shoot on how well the sensor is going to work.

Kerbouchard · 04-06-2019, 10:01 AM

Looks like bimmermilvs has a exhaust camshaft coming soon? Maybe I can hold off on the ESS long enough to do cam, milvs, ESS and valve cover gasket all at once.

Really annoyed too as I had a 30 day warranty from CarMax when I bought the vehicle. Had a local indy do a deep PPI for like $300 and they said car "needed nothing". whole top of valve cover was covered with grimey/oil mix when I removed the plastic engine cover. I guess unscrewing four hex screws isn't included in their "full inspection".

Local dealership also gave the car a "perfect"/"needs nothing" feedback when I took it in for PCV recall.

thanks guys! ;-)

03-31-2019, 01:50 PM	#1
Kerbouchard First Lieutenant 67 Rep 321 Posts Drives: 2019 330i ZTR Join Date: Jan 2019 Location: Texas iTrader: (1)	Misfire codes after 3SI Manifold Swap Hi All, Just completed the 3SI manifold swap on my N52 128i. Everything seemed really straight forward on the job, I labeled all connectors, everything "clicked" nicely upon re-install. I also replaced the eccentric shaft sensor seal and the intake resonator while I was in there. Note that I have not yet tuned the car (Bimmer Performance Center, etc.), so the ECM doesn't "know" there's a new manifold there yet. I know the tune is required to pick up the big HP bump, but I was under the understanding that the car would drive fine without a tune. Upon 1st startup, everything ran clean with no issues, no codes. drove slowly around the block, no problems. Took off from a light at 3/4 throttle and got "service engine soon" and a lopey idle. Nursed it back home, turned it off. When I turned it back on, the "service engine soon" light had gone off, but code reader showed P0301, P0302 and P0300 codes in "pending". Is there a common connector that I should check first to diagnose this, or do I just need to get the tune installed before driving it again? I'm hesitant to start taking the cowling and engine cover back off to double check connections in case it's just a software issue. Thoughts? Thank you!
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03-31-2019, 02:24 PM	#2
6ixSpd Save the manuals! 6082 Rep 6,774 Posts Drives: '16 M3, '23 718 Spyder Join Date: Feb 2016 Location: 416 iTrader: (4)	Those misfire codes are unrelated to the missing 3SI software. __________________ '16 M3 \| '23 718 Spyder Past: E92 M3, F87 M2, E39 M5, etc
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03-31-2019, 02:58 PM	#3
Kerbouchard First Lieutenant 67 Rep 321 Posts Drives: 2019 330i ZTR Join Date: Jan 2019 Location: Texas iTrader: (1)	Thanks for the quick reply! Based on another thread, I cleaned the oil off the eccentric shaft sensor connector using alcohol and a q-tip. Seems to have solved it? Go figure.
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03-31-2019, 08:22 PM	#4
nsjames Brigadier General 2469 Rep 4,328 Posts Drives: 08 328xi Touring Join Date: May 2017 Location: ohio iTrader: (0)	if you've got oil in the connector, chances are the ESS needs replaced. that's your early warning that it's failed. eventually the oil will sop it reading properly and you will have starting and running issues. at the very least check it again soon and see if there's more oil. It's been known to work it's way all the way up the wiring jacket and then bone the DME as well.
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04-02-2019, 01:28 PM	#5
bluewater328 Colonel 645 Rep 2,098 Posts Drives: 2011 bluewater 328i LCI sedan Join Date: Aug 2010 Location: Hawaii iTrader: (0)	Yeah, I did a re-read of his first post. While he replaced the ESS seal, he didn't replace the actual ESS. Hopefully the cleaning helps, and I suppose you could continue to do that till it actually dies, but that's going to be a problem as it's pulling oil into the sensor. Unfortunately, if it keeps coming back, that's going to mean removing the valve cover again to replace.
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04-02-2019, 05:54 PM	#6
nsjames Brigadier General 2469 Rep 4,328 Posts Drives: 08 328xi Touring Join Date: May 2017 Location: ohio iTrader: (0)	when mine was failing the car simply didn't start below 40F no idea why it was so buggered about colder weather, but that's what tipped me off. popped the connector, oil in it. cleaned it, was better, but then started to get worse on the starting front. Obviously once oil gets in there, it's a crap shoot on how well the sensor is going to work.
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04-06-2019, 10:01 AM	#7
Kerbouchard First Lieutenant 67 Rep 321 Posts Drives: 2019 330i ZTR Join Date: Jan 2019 Location: Texas iTrader: (1)	Looks like bimmermilvs has a exhaust camshaft coming soon? Maybe I can hold off on the ESS long enough to do cam, milvs, ESS and valve cover gasket all at once. Really annoyed too as I had a 30 day warranty from CarMax when I bought the vehicle. Had a local indy do a deep PPI for like $300 and they said car "needed nothing". whole top of valve cover was covered with grimey/oil mix when I removed the plastic engine cover. I guess unscrewing four hex screws isn't included in their "full inspection". Local dealership also gave the car a "perfect"/"needs nothing" feedback when I took it in for PCV recall. thanks guys! ;-)
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