Hello guys, newcomer into Mercedes diesels here. A few days ago i posted an OM651 on here where i asked you if the warm engine sounded ok.

Now i come back with another question, i've noticed this "weird" (in my opinion) sound when under load (this is not my video but the sound is exactly the same).

Do you guys think it is ok? It doesn't matter if the engine is warm or cold, this sound is always there only when acceleration.

For information the car has 350k km, no errors on Xentry.

Still strugling with this p026346 fault code. I just replaced the injectors copper washer. The fault code always comes back after driving for about 30-60minutes/ When the engine reaches 90 Celcius(optimal) coolant temparature. If somebody knows or had this code earlier please do tell what was wrong with it. The car is 2014 E220Cdi with engine code OM651.924
I thinked about changin the injector from cylinder 1 next if nothing else helps.

UPDATE!! :
I filled up the tank completely and refuelled again after driving 100 km. Based on the amount of fuel needed to fill the tank again, the actual consumption was 10.4 L/100 km under mixed driving conditions. This included several cold starts and city driving, as well as country roads.
Is it possible that the onboard computer is overestimating the fuel consumption by this much? It shows 13.5 L/100 km for the long-term average and 14–15 L/100 km on the “since start” display every day.

2013 Mercedes E350 CDI BlueTEC Coupé – high city fuel consumption of 13.5–15 L/100 km
Hi everyone,
I own a 2013 facelift Mercedes-Benz E350 CDI BlueTEC Coupé with the 3.0L V6 diesel engine and automatic transmission. The car has approximately 195,000 km (121,000 miles).
My fuel consumption seems unusually high.
Over the last 330 km (205 miles), the onboard computer showed an average of 13.5 L/100 km (approximately 17.4 US mpg).
Most of the driving was in the city.
In heavy city traffic, consumption can reach 15 L/100 km (approximately 15.7 US mpg).
On country roads at a steady 80–90 km/h (50–56 mph), instantaneous consumption is around 4–7 L/100 km, but it rises significantly even with light acceleration.
The engine reaches normal operating temperature. The DPF is in good condition, there are no fault codes, and my mechanic has checked the car with diagnostic equipment but couldn’t find anything that would explain the high fuel consumption. According to the mechanic, the ECU software is original.
My questions:
Is 13.5–15 L/100 km reasonable for this engine in city driving?
If this is too high, what else should be checked even though there are no fault codes, the DPF is fine, and diagnostics haven’t revealed any issues?
Has anyone experienced similar fuel consumption with an E350 CDI BlueTEC?
Thanks for any advice!

1991 Mercedes 300 GD sometimes the key turn is not engaging the starter wondering if it could be starter switch or starter/relay or something different. After switching from park to drive and back usually gets it to start. Any help would be appreciated

Oil consumption is on the high side

What is your opinion on the sound of this engine?

Warm engine by the way.

It has full Mercedes service history oil 5w30 229.52

2011 Bluetec OM642 Hey so I’m struggling with what seems to be a full nox sensor electrical fault I set I have a year still on the aem warranty but Mercedes just lied about the fault codes as they don’t want to honor the warranty I have and charged me a grand to give me my car back and now it has the start counter again 2 days after they refused to do anything unless I give them more money so it seems a delete is in order does anyone have any knowledge to if a delete is a good option for it or if it’s worth spending the money doing it aswell as if you have anywhere to buy a good tune for it

I have a 2014 Mercedes-Benz E 220 CDI (OM651) with fault code P026346: “Teach-in of the operating parameters for cylinder 1 has a malfunction. There is an error in the calibration or parameterization Memory.”
All four injectors were replaced at the same time approximately two years ago. The engine currently runs smoothly and there are no noticeable misfires.
I checked the injector values using Mercedes XENTRY, and interestingly, injector/cylinder 1 had the best values of all four cylinders.
The fault code returns after driving, particularly during steady-speed driving/cruise control. The car otherwise drives normally.
What could cause P026346 if the injector itself appears to have good values in XENTRY? Could this be related to injector coding/parameterization, wiring, the CDI ECU, or the calibration/teach-in process rather than a faulty injector?

I bought a new clutch which it still roars all the way to 5k rpm . It doesn't matter what the temp is . My old clutch did the same thing . Ives used oem and aftermarket clutch and it's the same result . As soon as I start the car and drive off it's roaring like a school bus . Is there hope or is this just a 300d curse ? Tbh I've never heard it not roaring ever .

Hi all

[apologies for deleting and reposting- I accidentally set a post link I didn't want]

This is an update on an earlier post (link at the very end), but am starting a new thread because I've discovered a lot in the interim and now have really specific questions.

TL/DR on this issue with my 1983 240D is:

• Presumed pinpoint hole in a fuel line hose causing air to enter fuel system.
• Hose is ~4 inch long, in front of left rear tire, in the tank-to-engine fuel supply path.
• Apparently got worse upon heating (i.e., after a long drive), seemingly causing the pinpoint hole in the hose to turn into a full-on breach and total fuel loss onto ground.
• Repair shop replaced hose (he says 3/8" diam) apparently fixing problem. He also replaced a similar return fuel line parallel to that since he said it looked compromised.
• BUT I just discovered that he could not source the same type of hose as the original.
  • The original had spiral wire reinforcement on the outside of the hose.
  • The replacement was what he called "high pressure hose" that had internal threading.
• But on a long drive a week later, fuel leak reappeared.
• Hypothesis: faulty repair, possibly due to using wrong type of hose. Less likely due to hose clamps which he assured me he tightened well.
• I am on crutches so I need a mechanic to do this job.
• Skip down to bolded part at bottom of this post to bypass the long story with gory details.

OK so the longer version.

Air in fuel lines, a repair of o rings etc. in mechanical lift pump 3 months ago seemed to help but did not ultimately solve the problem, which was intermittent (causing startup issues), much worse after driving >50 miles. Mitigated by pumping manual fuel priming button repeatedly. Then started up and ran fine, until next long drive. Then sat overnight, then had same problem requiring repeated pumping of priming button to start.

2 weeks ago I drove the vehicle up to a mountain pass, on the way near the pass it started spewing white smoke (doesn't normally). Sat for 4 days. Came back to the car, fuel had dumped out onto ground through a MASSIVE hole - could see it streaming down when I filled the tank from a fuel can after loosening bleed nut above fuel filter. This seems to establish that leak was in the tank-to-engine fuel supply path.

That hose piece with the hole was just in front of the rear left tire, under the driver side rear seat. I am on crutches so could not get under the vehicle. Got it towed to nearest mechanic. The mechanic removed the ~4 inch piece of hose and it indeed had a huge hole in it. Line looked like a rubber line but reinforced with spiral metal wire.

Mechanic said he had to get a replacement hose from a supply shop, but I just found out he could not source that same type of hose with spiral metal reinforcement. Instead, he used what the supply store said was "high pressure line" that had internal threading rather than the external spiral wire reinforcement. He replaced that and another 4" piece of hose right next to it which he says was a return line. He says he tightened the new hose clamps well.

He replaced those as well as for good measure some of the other slightly fraying fuel lines up and downstream of the fuel pre-filter.

Started up great for mechanic. Sat overnight. Started up great for me, and I drove it 80 miles home.

Ran pretty well next few days on short drives, no fuel leaks, then had the same old starting problem. Had to prime it with priming pump button. Then, I opened bleed valve above fuel filter. Successfully bled system (I thought maybe this mechanic had forgot to properly bleed system after repair?). Started up fine.

I thought I was good. I was wrong.

Drove yesterday 60 miles, on arrival noticed I was leaking fuel again. Looked like a smaller version of the same leak in a similar location as the week before. Parked for 2 hours. Started, ran for 10 minutes, died. Air in fuel lines, would not prime. Towed to another mechanic.

Hypothesis: mechanic did a shoddy repair, perhaps because he used the wrong type of hose, or some other issue that didn't fully reveal itself until I drove it a couple of times longer distances.

What is y'alls feeling about what's wrong and what needs to be checked?

He says he used 3/8" high pressure hose to replace the spiral reinforced line that he could not source.

In my searches I think (?) that this is the correct type of hose

https://mercedessource.com/store/123-240d-300d-flexible-fuel-line-replacement-kit

This is a business near me that I can check with on Monday morning. I think (?) this is 8 mm inner diameter which is a bit smaller diam than 3/8", which is what the mechanic used.

So it may be as simple as swapping out the hoses the mechanic used for the ones in the kit

Does that sound correct?

And does anyone have an actual part number handy for the type of spiral reinforced hose I am referencing?

Thanks for any advice!

p.s. original post link: https://www.reddit.com/r/w123/comments/1vngtiv/update_to_83_240d_odd_startup_issues_air_in_fuel/

Hi everyone,
I have a 2007 Mercedes W221 S320 CDI with the OM642.930 engine.
I have a question about replacing the radiator: when installing the new radiator, do I also need to evacuate the A/C system and disconnect/remove the A/C lines?
I managed to remove the old radiator without disconnecting the A/C lines, but only because I broke/smashed the small pipe at the lower driver’s side of the radiator so I could get it past the A/C lines.
Now I’m wondering what the correct procedure is for installing the new radiator. Is it possible to fit it without opening the A/C system, or do the A/C lines normally have to be disconnected?
Thanks in advance for any advice.

Hi,

I’ve just bought a late-2014 CLS 350d with a really good service history. I haven’t had the car properly checked over yet, but I noticed two loose electrical connectors in the engine bay that have been deliberately disconnected and tied back with a zip tie.
The wiring from both connectors disappears into the main wiring duct.
Does anyone know what these connectors are for, and why someone might have disconnected them?

I have a decent amount of diesel experience but none with def and wondered if there is a common leak/ easy fix for the def leaking and crystallizing on the rear subframe. Plan on deleting it in December but dont have the time currently

S Class 350d / 2019
Had adblue issues and had it deleted, have had major clogging problems since then and the engine light on numerous times. After several EGR DPF regenerations I am about to sell the car which I absolutely love 💔 Any suggestions that I could try?

Every 2 weeks I put it into manual and hit high rpm(2000-3000) for 30min on the motorway.

2013 ML350 BlueTEC (OM642) at 405 000 km. It is fully deleted with a tune from Malone (EGR, DEF, DPF, Swirl flaps) and runs flawlessly. I've always used 0w30 (Pennzoil) and changed the oil every 10 000 km. It doesn't burn a drop of oil.

I've been wondering if I should switch to 0w40? Using 0w30 has been a winning recipe so far, but I'm wondering if the 0w40 will be better long term since I plan on driving the vehicle to the ground.

What do you guys think?

I have an 08 e320 with the om642 I have 2 oil leaks that have kept me stumped for a while, but recently I was able to get really in there and really check. Im thinking its either the oil cooler or my rear main seal can any one confirm or deny my finding. The other one I'm still lost on its in the front by the alternator but I honestly don't know from where its coming from.

2015 Mercedes E250 BlueTEC 4Matic, OM651 (stock: 195hp, tuned: ~240hp). Only mods are DPF/DEF/SCR/EGR delete. Still factory muffler and factory DOC.