fuel injector retention bracket bolts vibrating loose

marinpop · 08-21-2021, 06:08 PM

I searched the forums and didn't see anyone else with this issue.

Just finished troubleshooting and found all three of the injector retention bracket bolts had backed off causing rough running and misfires.

I had previously replaced the seals and decouplers and reassembled everything, torquing the bolts to 13nm per spec.

This time I decided to use some blue thread locker and I'm tempted to tighten them down a little more - 13 nm seems like nothing.

Anybody have any thoughts or advice?

lookalikehuuh · 08-22-2021, 04:27 PM

So you used thread locker, torqued them properly and they still backed out? Sounds like something else is at play here. Do your injectors fit really loose in the head or something?

kfrazie1 · 08-22-2021, 04:59 PM

I know this may sound stupid, but did you put the brackets on facing the right way? I believe there is a slight curve in them so if you put them on upside down, they don't tighten down with the added tension from the curve.

marinpop · 09-09-2021, 08:52 PM

I put thread lock on after I found that they had backed out and the vehicle was running rough.

They still seem to be in there as the vehicle is running well. I will take a closer look at them as well as confirm the orientation of the bracket when I have a free moment and report back.

08-21-2021, 06:08 PM	#1
marinpop New Member 0 Rep 9 Posts Drives: BMW 335i, Porsche TurboCayenne Join Date: Aug 2021 Location: Northern California iTrader: (0)	fuel injector retention bracket bolts vibrating loose - misfires I searched the forums and didn't see anyone else with this issue. Just finished troubleshooting and found all three of the injector retention bracket bolts had backed off causing rough running and misfires. I had previously replaced the seals and decouplers and reassembled everything, torquing the bolts to 13nm per spec. This time I decided to use some blue thread locker and I'm tempted to tighten them down a little more - 13 nm seems like nothing. Anybody have any thoughts or advice? Last edited by marinpop; 08-21-2021 at 11:20 PM..
	Appreciate 0 Tweet Quote

08-22-2021, 04:27 PM	#2
lookalikehuuh Major 700 Rep 1,229 Posts Drives: 2006 330i, 2007 335i Join Date: Sep 2014 Location: San Diego, CA iTrader: (0)	So you used thread locker, torqued them properly and they still backed out? Sounds like something else is at play here. Do your injectors fit really loose in the head or something?
	Appreciate 0 Quote

08-22-2021, 04:59 PM	#3
kfrazie1 Lieutenant 64 Rep 553 Posts Drives: 335i Join Date: Aug 2010 Location: NY iTrader: (4)	I know this may sound stupid, but did you put the brackets on facing the right way? I believe there is a slight curve in them so if you put them on upside down, they don't tighten down with the added tension from the curve. __________________ Montego Blue E90 335i 7" VRSF IC \| OFT Tune \| DCI \| RB PCV \| Secondary CAT Delete & CYBA 3.75" Tips \| M3 Front \| Mtech Rear \| CSL Trunk \| 219M \| KW V1 \| AA CP
	Appreciate 1 lookalikehuuh699.50 Quote

09-09-2021, 08:52 PM	#4
marinpop New Member 0 Rep 9 Posts Drives: BMW 335i, Porsche TurboCayenne Join Date: Aug 2021 Location: Northern California iTrader: (0)	I put thread lock on after I found that they had backed out and the vehicle was running rough. They still seem to be in there as the vehicle is running well. I will take a closer look at them as well as confirm the orientation of the bracket when I have a free moment and report back.
	Appreciate 0 Quote