Got my injectors from the shop, engine nails the same... - Page 3 - PeachParts Mercedes-Benz Forum

tobybul · #31 03-07-2008, 11:28 PM

where abouts in VA are you from then?

ramtony · #32 03-08-2008, 08:07 AM

I'm in Virginia Beach south side... near Nas Oceana.

ramtony · #33 03-08-2008, 08:15 AM

thanks, I working right now, but this afternoon when i get back home I will upload the file, not sure if in fact the sound is normal but, I remember back in dec, I drove to orlando FL, 11 hours strait driving, that night when I got to orlando I let the car running for like 10 minutes, I could not believe how quiet it was. but next morning it was just as usual very load.....

Magoo · #34 03-08-2008, 08:24 AM

In order to confirm Tobybul's theory, you could run the car from a small container of Diesel fuel, just like doing a diesel purge.

michael cole · #35 03-08-2008, 09:04 AM

ive done injectors on several cars over the years.i find they are usually much more noisy at first.once the tips get a little carbon around the orifice they seem to quiet.but this process can take some time.the carbon produces a "throttling" effect on injection resulting in lower peak cylinder pressure and combustion noise.i recommend at least a gallon of canola initially.if you get enough in there it will start to produce a longer smoother burn and less noise

ramtony · #36 03-08-2008, 06:03 PM

two files here. first is when the engine is cold, first start of the day. the other one is after the glow plug cycle and normal operating temp. just ignore the pop up, close that up and scroll down.
towards the end of the cold engine file you can hear when the glow plug cycle ends, and the nailing begins... just fast forward....thanks

http://upload2.net/page/download/ByevfjYS5iLs7dS/warm+emgine.wav.html

http://upload2.net/page/download/XtqaGzJt2BHRMVC/Cold+engine+om606.wav.html

jcciem · #37 03-09-2008, 12:00 AM

After listening to the audio clip, I can hear the nailing clearly, maybe one or two during the glow plug cycle, but a rapid deterioration to constant nailing once it ends. Hard to imagine that a MB mechanic would classify that as normal or good. It is neither normal nor good. It sounds like an audio clip of my engine when mine was doing the same thing. I don't know if you aware of it, but it's not a good thing to rev an engine not under load to extreme RPM's. Hearing you rev that engine in the audio clip, all I could imagine is you wiping out a main bearing. i've attached a file of mine nailing, running on pure diesel no canola oil added. It's a little hard to hear above the regular diesel noises, but it's the sharp metallic clinking, pinking, ball peen hammer on metal sounds.

ramtony · #38 03-09-2008, 10:32 AM

so how did you fix your car?, and where is the sound file... thanks for the imputs, that nailing is driving me crazy...

ramtony · #39 03-09-2008, 03:01 PM

can anyone else elaborate on this? if not the injector what?

Number_Cruncher · #40 03-09-2008, 04:29 PM

Does your car tick over at 640 rpm?

I took a quick look at the cold wav file, and, after you rev it and the nailing starts, I cut a section of the file and plotted it.

I replaced the time axis with engine rotations (just a scaling - 640 rpm was the number that dropped out from my observations/calcs).

This enable me to see that the noise comes and goes in various cylinders, but, there is one cylinder which makes noise quite consistently. So, I think there's something wrong that's cylinder specific (cylinder, injector, IP element, pre-chamber, valves), rather than general, like air in the system, or unsuitable fuel.

ramtony · #41 03-09-2008, 06:03 PM

well, what is the likelihood of a valve being the problem? since you usually cannot hear it, when the engine it's coold....

also disconnecting any single injector line wont change much the noise, but changing any two at the same time would make the noise go away...

keep in mind after the Orlando trip, the engine was quiet that night, what's what i don't understand....

where does one go from here?

Number_Cruncher · #42 03-09-2008, 06:20 PM

>> where does one go from here?

Compression test all cylinders (actually, this test should happen far earlier in most diagnostic routines than it actually does - perhaps most owners are too worried what the results might be?). First dry, and then, add a spoonfull of oil via the intake ports and re-test. Post the results.

ramtony · #43 03-10-2008, 11:21 AM

i'm goint to try the easy stuff first... since I don't know if Po change the washer and o rings on the injection pump I planning on changing that next...

tobybul · #44 03-10-2008, 12:37 PM

This is obviously on a much newer model. If this were a 617 I would say it sounds normal.

My take on this is try pure synthetic oil. It could be just dirty in there and syn will help clean it up and quite it down. I probably would not mess with the IP parts for now.

ramtony · #45 03-10-2008, 07:28 PM

today, o change my injector return lines with viton from fryerp... and after letting the engine idle to operating temp , nailing IMO is less frequent... I uploaded another sound clip.
Is this normal sound for the om606 turbo?
http://upload2.net/page/download/oN3udXxJciPAZbD/080310_01.wav.html