Trainingdragon

This has probably been covered but I couldn't find a thread on it.

I've heard that the W211 E63s are recommended to change the fuel injectors around 60k miles +/-. I have about 74k miles and have a little bit of a rough throttle at low RPM. Once I'm moving it seems to run great. So just curious, is it really a good idea to replace the injectors as part of routine type of maintenance? Also, the car is not kicking out any codes so I'm wondering what could be causing the slightly rough low throttle engine feel. Idles well so only light throttle while revving in park.

Thanks everyone

W126AMG

My indie shop recommended I change the injectors when I had upper engine work done - SLS Black Series hydraulic lifters, cam adjuster plates upgrade, etc.. Not terribly expensive. I was at 107k miles

almostordinary

I replaced mine on the last servicing of my intake manifold (Had a throttle body go out).

They were on sale so couldn't pass it up.

My car just clocked over 100k miles, also just replaced the fuel pumps and sending unit since I was getting a low fuel pressure code.

Just posted on that here:
https://mbworld.org/forums/w211-amg/...rts-tools.html

Trainingdragon

Almostordinary. How many miles were on your E63 when you did the injectors? What prompted you to replace them? Any issues or did you do it just for good measure? Also, where did you get them? I can't seem to find a good price on them.

Thanks

Solo wing

There has been a good number of injectors sticking open and hydrolocking M156 engines. IMO this is reason enough to change the injectors before they stick open. Not to mention the added power and efficiency.

E63007

Back in 18’, just after buying my 2007 E63 (w/94k mi.), I had dropped off my original injectors to get tested while I was rebuilding the Heads, Intake Manifold, Front Suspension, P/S Pump and when I had installed everything and tried starting it, it sputtered and coughed as it was trying to start and after maybe 10 seconds, I turned the ignition off!!! Granted, I was a little nervous after having rebuilt the car which took me 5-6 months! So I took out my Ratchet wrench with the appropriate spacer and manually tried to turn the Crank, but it was a No Go! I then removed the Spark Plugs and went at it again and immediately noticed gas spewing from cylinder 3, so I got out my trusty siphon tube and must have sucked out a pint of gas! Same thing only a little less for Cylinder 4! So I too had experienced the dreaded Hydro Lock, only Difference being that my Spidey Senses served me dead on right as I had Turned off the ignition when I did! Had I been driving in gear, it would have been a much different story! Needless to say, I was less than pleased with the guys that “Tested” my injectors. On the other hand, if this had occurred in an uncontrolled environment and had I not discovered this at this moment, I’d most likely have had something very bad happen later!

I proceeded to inspect all cylinders and then busted out the Boroscope to take a look at the Intake through both the Air Side and the EVAP. The Air Side had a pool of fuel so I wrapped some blue shop towels around a bent L-Shaped wire hanger with Duc Tape and that combined with using the boroscope managed to clean up most of the fuel. I then positioned a fan and let it run for 24 hours in an effort at trying to evaporate any residual fuel before trying again. The EVAP (Top) side was seemingly dry. I’m honestly still kind of mystified as to how so much fuel could have ended up in the Intake??

STAR/XENTRY- Showed me codes for numerous Misfires due to this HydroLock at the first Start in 5 Months! So I simply cleared all codes for the engine.

I ended pulling the fuel rail with the injectors all on (I only attempted to do this because I had previously applied silicone “Dielectric” Grease to each injectors O-ring seal, so I knew it would pry out rather easily) and when I did, I could see a constant drip of fuel moving from the same Cylinder 3 Injector! I ended up buying a new OEM Set from RM European ($28/ea at the time!) and haven’t had an issue since. When I installed them, due to the rail indicating it was leaking even after I had siphoned off what was in there, I reinspected and sure enough, there was more to clean up!

I little Pearl of Wisdom handed to me by one of the Tech’s at my local Mercedes was to keep the injectors harness disconnected from each injector in order to prime the Oil Flow first before trying to start after such a rebuild where the engine was dry for several months. This has the duel effect of priming not only the oil feed to the Engine/Cams but also the Fuel Rail itself! To do so, you simply Disco the Oil Cap and have someone watching for oil flow while you Turn On/Off the ignition. It took about 20 tries before oil could be seen sloshing around the Cam Shafts. Then I hooked up the Injectors to their harness’ and it started right up! Thank Goodness!!!

In retrospect, it may have been that my 3rd and 4th Cylinders (ie-those closest to the entrance of fuel to the Rail itself at the firewall on the Driver side) didn’t have enough pressure built up, as the entire rail would have been empty of fuel, prior to the rail being “filled” with fuel being pumped from the tank which may have caused for those injectors to foul, due to lack of pressure? That would explain that during testing they may have passed, but under “Abnormal Circumstance” without enough fluid pressure in combination with fluid being pumped in, that injector may have defaulted to remaining open, thus flooding the cylinder(s)? By doing what I mention above, 20 cycles of off/on, it should get fuel to the rail gradually and, without the harness connected, the injectors stay closed. It’s a mystery what happens to all the air in the rail? It would be cool if you could open up the rail to bleed off air to be certain!! Perhaps this could be done by not installing the #5 injector and cycling the ignition until Fuel squirts out, but that might be unnecessarily messy!