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Discussion Starter #2
Ok, Guys. I know that Rossafuss had a problem that ended up being his fuel pump, but mine is different.
This car has 195k miles on it and it has a distinct extra sound.
Here's a video that I made before I pulled the valve cover off. I held the earpiece of my stethoscope up to my phone. It mostly transmitted the sound accurately.
Here's another one with some revs to show how it is proportional to RPM. I'm new to diesels, but not new to fiddling with engines. This car was apparently driven with this sound for at least a few thousand miles. It has not gotten louder or changed frequency.
Oil Filter looks like this.
Injectors look like this. Previous owner had them out and they came out easily by hand with no issues. #1 looked like THIS when I pulled it. Like it had some flaky junk on the tip of the nozzle.
I can compress all of the intake lifters a little less than a quarter inch when in the head, but can not compress any of the lifter pistons by hand when I have them out. I'm fairly sure I'm not compressing valve springs by hand leaned over the engine. I rebuilt intake lifter 4-1 today. It was the only one I could get apart by whacking it on a block of wood. None of the other pistons will budge but they turn freely.

Any help is appreciated. I'm almost ready to just put the whole thing back together and try to figure out how to run a load of diesel purge through it. Is there a simple way to connect the fuel filter inlet directly to a return so I can run the pump inlet directly in the diesel purge?

Thanks, guys. I really want this to run properly.
 

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2000 S430, 2003 S430, 2000 S500, 2003 S600 TT, and 2005 E320 CDI
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Lots of fuzz on that oil filter. I'd recommend an oil and filter change regimen of every 5,000 miles with a good quality oil. Generally I recommend Mobil-1 0W-40 FS European Formula because it's relatively inexpensive at Walmart, readily available, and correct for the OM648 engine (among other oils). The oil itself being very dark, that's typical of Diesels. My truck, also a Diesel, does this as well. That's normal.

After almost 200,000 miles, it's possible that your injectors could use a good overhaul. I would recommend pulling them out and having them serviced. The reason for this is that I also have a 2003 S600 TT with 175,000 miles on it. The injectors definitely needed overhauling; spray patterns were all over the place, as was fuel flow rate. The internal filters were totally gone. Given the much higher fuel-rail pressures in the CDI's injection system, you're clearly getting fuel, but proper atomization of the fuel, including Diesel fuel, will help that engine run as it really should.

I am able to view the videos, but I'm getting no sound from them.
 

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Discussion Starter #4 (Edited)
Sound should come up if you click the play button in the upper right corner. Apparently the googles just generates a preview with the link. I just got all the intake lifters disassembled. They were extremely stuck shut. Soaked in simple green, seafoam, and PBlaster for a few hours and I whacked them all open. I'll get to reassemble them on Tuesday so they'll be soaking until then.

The way I understand it, they should compress a small amount by hand, but basically be rock solid under the cam even when the valve is closed. I'll work towards that unless instructed otherwise.

For sure that oil needs to go.

Thanks

Sent from my SM-G955U using Tapatalk
 

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2000 S430, 2003 S430, 2000 S500, 2003 S600 TT, and 2005 E320 CDI
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Ah, I see. Got them to play, thanks. Didn't realize that was just the "preview".

Your engine sounds just like mine, and I keep the decorative "CDI" black cover off. Diesel engines do sound like this, and it doesn't sound like you have a problem to me. The OM648 engine is going to sound a bit like a mini-Cummins or a John Deere. It's a Diesel. :)

My car was owned by a "snow-bird" couple who used their car going between New Hampshire and Florida, and they were the original owners, so, of the 145,000 miles that the car now has, most of it was apparently highway miles. They clearly took good care of this car before I got it.

Maybe @Rossafuss can chime in with his greater experience.
 

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Discussion Starter #6
I feel like the knocking sound is more clear in the second video. I'm pretty sure I shouldn't be able to hear it on the highway (which I can). Either way there's no way those lifters were adjusting themselves in any way judging by how incredibly stuck they were in the buckets.
 

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2005 E320 CDI *black on black with nearly every option*
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That knocking sound (i can't hear it at all in the first video, but its pretty clear about half way through the second video) is NOT normal. It actually sounds to me like a mechanical knock, not so much a fuel combustion knock. Lifters sound more like a high pitched ticking when they're stuck (imagine tapping two hammer heads together). the lifters are NOT supposed to be squishy at all, they're basically mini hydraulic pistons. oil doesn't compress so they should be able to maintain consistent travel under load.

I would send an oil sample to blackstone labs to see if they can detect higher than normal metal content. my noise problem wasn't the fuel pump, but the fuel pump drive sprocket. the bolt that holds that sprocket to the head had backed out slightly, causing a slightly loose timing chain and that drive sprocket to slap around in there. the sound was much different than you're hearing, the noise i had was more of a slapping noise rather than a knock you're experiencing.
 

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Discussion Starter #8 (Edited)
True. I'm really hoping this isn't a bouncy piston. The sound really doesn't change when pulling individual injectors, and it doesn't cause any crazy vibrations. It is very clear, though. Any other ideas what it might be?

It's so consistent and steady, it makes me wonder if it's a bolt backed out somewhere that rotates.
 

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if it is mechanical, it will show up as excess metal particulate in the oil. have an oil test done.
 

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Discussion Starter #11
Well it was definitely NOT lifters. Put everything back together last night. It started on the third try after a few key on/offs to pump the air out. Knock is still there. Maybe almost more clear since I had the injectors in the ultrasonic bath to clean them.

Anyway. I pulled the injectors right back out and they went off for testing today. I'll send an oil sample to Blackstone on Monday and pull the pan while it's empty to see if I can shake any rods. In the mean time I'll be doing brakes, shocks, and bushings all around. I also have a used diff here to rebuild. I probably should have just bought the one I looked at that had black death on #2 and leaking #5, but whatever. At least I'll know this one inside out.
 

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The more videos I watch, the more I think it's piston slap or a spun bearing.
If you have a spun bearing, no oil gets to that bearing. My MB filters are not fuzzy on 06 E320, but what I hear is likely connecting rod knock.
 

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Discussion Starter #14
Got my injectors back from testing. Number 2 had a crack in the nozzle. SOOOOOOO...... I put another 648 injector that I got on ebay into that hole and.



TA DAAAAA

I know I need to pull and reinstall number 4, but that's not a big deal since I have about at least two more sets of bolts and seats here.
 

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Discussion Starter #17
We're not out of the woods yet, but it seems I may have dodged the biggest bullet. Oil change with sample for send-off is next after I fix the last suspension bolt, check all the torques, and put some miles on before an alignment.
 

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Discussion Starter #18
There's still something going on for sure. I'm hoping this is an injector timing issue since just throwing a different one in to replace the cracked nozzle one made such a big difference before I went out of town. All I did today was replace shims.

Sounds like this:
 

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So this vid is after you replaced the injector? Because it still sounds like rod knock, but maybe you have a bent valve, frozen lifter. get the car on a lift, or four jack stands, crawl under and take a similar video at the crank case with engine running. See if the sound is louder underneath.
 

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It's not lifters, lifters make a higher pitched tapping noise more than a knock. That sounds like a rod wacking something.

Sent from my SM-N950U using Tapatalk
 
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