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lumberjack727 lumberjack727 is offline
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Car: 2008 535i
Default leaky injector help!! - 02-17-2018, 07:04 PM

I have an '08 535i n54 engine 90k miles.

I am having a bad cold start with rough idle and smoke coming from the exhaust. Car runs strong at WOT, but can feel it break up slightly and random loads and rpm's under normal driving.

within the past 500miles i have replaced

-coils - https://www.am-autoparts.com/product...?m=1267&y=2008

-plugs - NGK 95770 gapped .022 with feeler gauge and checked with mic.

-6 new index 12 injectors, coded.

-Walnut blasting

super simple mods

-bms intake filters

-cobb v2 stg1 aggressive

-charge pipe retaining dv's

Yesterday when i started the car it was typical rough idle. I let it idle for about 10 seconds then shut it off and pulled plugs. #4 was wet and smelled like gas. I assumed that a new injector i just installed was bad so i buy another one to replace it to test or have as backup. I install new injector in cyl #4 code it and the next morning same problem, cold start rough idle with smoke. I shut it off after a few seconds of idling and pull plugs again. #4 is wet again.... I swapped #3 & #4 coils today thinking maybe the cheap coils from Am Auto Parts were a bad choice? I am going to see if the problem follows the coil in the morning. I also pulled the plug on the #4 injector to see if it is getting some ghost voltage and opening it partially? So in theory if the #3 plug is fouled in the morning the coil is bad and the injector doesn't leak with or without being plugged in. Or if #3 AND #4 are not fouled out, the coil is good and the injector is getting voltage and opening somehow. If #4 plug is still fouled out ill swap #3 & #4 plugs and see what happens.

If that doesn't work then what? Anyone have this problem before? I did a search and couldn't find anything.

Also It will not throw any codes if i let it idle for about 30seconds before i back out of the garage and idle smooths out. But, If i try and slowly bring the rpms up in idle right after i start it, it will beark up and throw several codes. misfire cylinder 1,2,4,6,7, and a multiple cylinder misfire code.

Thanks in advance!!

Last edited by lumberjack727; 02-17-2018 at 07:09 PM..
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Mr. T Mr. T is offline
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Join Date: Sep 2015
Car: 135i
Default 02-22-2018, 08:46 AM

From my understanding of installing injectors, if not done properly the holes in the head that they sit in can actually be deformed slightly during install/removal, and thus when the new injectors are seated they won't seal properly and cause the problems you're getting. I'm not entirely sure if that's accurate, so if I were you i'd wait for someone with more technical knowledge than me to chime in or give it to your trusted indy.
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Ocean Ocean is offline
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Car: 2008 535i Sport
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Default 02-22-2018, 06:42 PM

Agree w Mr T. Check if those injectors are seated properly. The retaining bracket should push them down the last 1/4 inch or so. Inspect the seals on the tips.
Moving them around the banks is a good idea to rule out it is the injector itself. Could be the bore being widened in which case I have a fix called Teflon. Its cheap and works.
I recommend Delphi coils. Not expensive.https://www.fcpeuro.com/products/bmw...yABEgISu_D_BwE

Sleeper 5 series
Performance: Pro tuned MHD, xHP Stage 3 TCU flash, DCI, AR kittens, ER FMIC & CP, Fuel-It Stage 2 LPFP w ported rail, RB turbos, RB inlets, KW V2, Mfactory LSD
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Nitrousbird Nitrousbird is offline
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Car: '07 335i 6MT
Default 02-23-2018, 04:17 PM

I wouldn't trust those coils. I'm pretty sure the AA coils I got from Amazon fried my MSD80 DME (and yes, I replaced the MOSFET's...now getting towards a MSD81 swap).

I found a set of new Eldor coils on eBay for $130 shipped. Eldor's are the newest coils BMW is using now.
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lumberjack727 lumberjack727 is offline
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Car: 2008 535i
Default 02-24-2018, 12:56 PM

update: The wet plug followed the coil. So clearly the coils from Am-AutoParts are junk. I cant believe I didn't notice it before, the factory Bosch coils weigh 2x as much as the cheap AmAuto ones.

So currently I have all of the old Bosch coils in and going back and forth with AmAutoparts refusing to give me a refund or allow me to use them as a credit towards the delphi coils they also carry. They replied in several arbitrary emails to my request to pay the difference for the Delphi but they will only replace it with the same product.

On the bright side I am now experiencing about every 4th start or so a long cranking before it will come to an idle. As well as the infamous half engine light and reduced power mode with the 30ff low boost code. I am assuming hpfp for the long start? And I have an aftermarket cp but it retains the factor(90kmiles) dv's. Im assuming maybe the dv's are leaking causing the 30ff?

I can shut the car off and let it sit for several minutes and pull the vacuum line off by the oil filter and holds strong vacuum.

So in summary i am waiting to see if i can get a credit towards the Delphi, if not ill research more and figure out what coils to go with. And BOV's sound mo betta anyway so i might as well take out my aftermarket cp w/dv's and go Tial/hks just to eliminate that variable. I called BMW and my car is still under the extended 120k miles/10yr HPFP warranty so I want to try and confirm that is the long start problem so i don't pay them to say it wasn't the hpfp.

Any thoughts are greatly appreciated,

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