Noisy injectors

Post your E12 technical questions and comments here. Please, no off-topic posts.

Moderators: Mike W., Pierre

Post Reply
User avatar
RonDwyer
Posts: 470
Joined: Sun Mar 01, 2009 7:01 pm
Location: San Francisco Bay Area

Noisy injectors

Post by RonDwyer »

Got the 5 back on the road finally, mostly there on the smog check, it runs a little lean, playing around with resistors on the CTS circuit. I have noticed the injectors seem to be noisier that I recall. The E12 is not exactly well insulated from engine noise.

Here's my question, there seems to be a lot of places offering rebuilt injectors. Are these places actually separating the steel housing from the plastic solenoid housing and replacing parts inside or is this just a clean and test gig? I cant seem to get my mind around how one would take an injector apart. They seem to be permanently bonded together.

Does anyone have any firsthand experience with any of these 'rebuilders' and is this the best way to go vs. new? I'd be worried about getting chinese junk if i order new ones.
Ron Dwyer
Milwaukee, Wi

14 Audi A8L TDI
03 530i
08 F150 4X4
Qwodracer
Posts: 69
Joined: Sat May 14, 2016 6:03 pm
Location: Cambridge, Ny

Re: Noisy injectors

Post by Qwodracer »

RonDwyer wrote:Got the 5 back on the road finally, mostly there on the smog check, it runs a little lean, playing around with resistors on the CTS circuit. I have noticed the injectors seem to be noisier that I recall. The E12 is not exactly well insulated from engine noise.

Here's my question, there seems to be a lot of places offering rebuilt injectors. Are these places actually separating the steel housing from the plastic solenoid housing and replacing parts inside or is this just a clean and test gig? I cant seem to get my mind around how one would take an injector apart. They seem to be permanently bonded together.

Does anyone have any firsthand experience with any of these 'rebuilders' and is this the best way to go vs. new? I'd be worried about getting chinese junk if i order new ones.
A "rebuild" is typically a vibration clean, new cap, new screen, and 2 o-rings.... the inner (oring) if bad is not typically replaced and labeled as a "lifetime" part, meaning it goes bad you need a new injector, as is the coil and the plunger.

A Bosch part number is a Bosch injector.. they are putting their name on it. Don't get an off brand if you are worried about Chinese crap

I did notice my injectors are loud, but to me it's not worth the hassle of any of these steps, even thou I have everything to exactly as the rebuilders do, I could just do it myself.


You mentioned in another post you are running slightly lean, after sitting 5 years, perhaps the end of the injector is slightly plugged from these crap ethanol fuels and causing this condition. So it may be worth the effort for you to do something.
81 528ia black - semi-dd
92 BMW K75 - dualsport/cruiser
03 Chevy Silverado 1500hd - tow-rig/bad weather
84 Toyota celica supra - drift/autox/hillclimb duty
User avatar
Mike W.
Posts: 2889
Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Post by Mike W. »

Agreed on them not taking them apart, although I've had plenty of -152 injectors start leaking from the body. I've got a boatload of E28 injectors, I ought to try to take one apart!
Mike W.



02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Post by T.Hanson »

Does injector cleaner in a bottle work at all for light maintenance ?
User avatar
Mike W.
Posts: 2889
Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Post by Mike W. »

T.Hanson wrote:Does injector cleaner in a bottle work at all for light maintenance ?
I've had some success with Techron. Not cleaner with Techron, straight techron. Nothing else I've used did any good at all. I've also heard good things about BG44 but I've never tried it.
Mike W.



02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
PatinaBeforePolish
Posts: 393
Joined: Sun Jan 18, 2015 1:22 pm
Location: Baltimore, Md.

Post by PatinaBeforePolish »

Ron,

I've always used Mr. Injector.

http://www.mrinjector.us/

Fast service, returned with a before and after flow graph.
79 528i
76 530i - Stored since 1992, can it be brought back to life?
86 944- 2023 project
78 F150- Everyone needs a truck
Post Reply