May need camshaft adjuster replacement
I get rattle noise when starting car, but VERY RARE. Maybe 5% of the time.
How much time do you think I have left do replace camshaft adjuster?
I saw this video. Its in foreign language, but I think I got most of it figured out. Pretty much of someone holds crank bolt in place, the camshaft adjuster bolt can be removed without messing with valve covers.
I assume vehicle can be driven at least until actually check engine light comes up.
I've seen fcp euro sells those adjusters for about $400 each. Any other good place to buy them?
If and when I will do it, I'll definitely make a very DIY friendly youtube video.
Last edited by pahanorlando; Jan 3, 2025 at 10:26 AM. Reason: Fixed link




You can easily test without removing anything by rotating crankshaft main pulley while listening for a snap or reading live CPS position.
If camshaft position is proven not skipping forward then you're good to change only the 2x cheap chain tensionsers.
Use better oiling to help camshafts wear, HPFP, CPS and tensioners.

Last edited by CaliBenzDriver; Jan 3, 2025 at 07:20 PM.




2) What is considered "good" oil to reduce wear? Ive always used Mobile1, but local german car shop told me Motul is much better, and I should stop using Mobile1. If the major maintenance is recommended (chains and all associated parts), thats gonna be a big bill. Advice/experience welcome!
MOTUL is a great upgrade because it holds its viscosity longer before derating into W30.
The VVT's single lock pin wears due to low pressure forcing zillions of lock/unlock operation... worn pins are unable to lock and cause rattle.
> Short Term :
-- use better oiling conditions, experiment "oil pump solenoid" disconnect - See W212AMG thread
-- Long crank is caused by poor camshaft positioning: VVT locks, Leaky CPS, Limp chain Tensioners all of which are affected by poor oiling conditions.
> Long Term :
-- we will all need priceless VVT Gears replaced or rebuilt.
-- If we manage conditions to push repair time frame well, we can ignore that!
Last edited by CaliBenzDriver; Jan 4, 2025 at 03:18 PM.
I get rattle noise when starting car, but VERY RARE. Maybe 5% of the time.
How much time do you think I have left do replace camshaft adjuster?
Video
I saw this video. Its in foreign language, but I think I got most of it figured out. Pretty much of someone holds crank bolt in place, the camshaft adjuster bolt can be removed without messing with valve covers.
I assume vehicle can be driven at least until actually check engine light comes up.
I've seen fcp euro sells those adjusters for about $400 each. Any other good place to buy them?
If and when I will do it, I'll definitely make a very DIY friendly youtube video.
VIN: 4JGDA5JB6EA417762
I assumed P002177 specifically points to bank 2 intake adjuster, but good to know that it could be chain tensioner.




VIN: 4JGDA5JB6EA417762
I assumed P002177 specifically points to bank 2 intake adjuster, but good to know that it could be chain tensioner.
Let's not get a $10,000. complete repair job blindly until necessary.
Quick troubleshooting will help pin point your issue:
> Do you get STARTUP RATTLING noise??
-- If No rattle then Intake VVT Gear still ok.
-- Perhaps $50 Cam sensors: Inspect them.
Last edited by CaliBenzDriver; Jan 6, 2025 at 02:45 PM.
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Let's not get a $10,000. complete repair job blindly until necessary.
Quick troubleshooting will help pin point your issue:
> Do you get STARTUP RATTLING noise??
-- If No rattle then Intake VVT Gear still ok.
-- Perhaps $50 Cam sensors: Inspect them.
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You have to read livedata, but I would just honestly replace them as a part of maintenance. What mileage are you at? Can you show me the timing cover area of the engine to see if anything is oil-soaked?
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"A warning to all M278/M176 owners..."
. Apparently that is a major fix of $10k+ (new wire harness). To remove the plugs on cam position sensors, pull out the retaining lever, press it in toward the plug body to release the lock, and pull apart. A set of 4 Genuine Mercedes sensors is under $200 on AutohauzAZ...I just got a set myself.Last edited by Leetom; Jan 7, 2025 at 08:19 AM.
I thought about reading livedata too, but I guess since it happens less than 5% at this time, it might be tough to see anything in scanner live.
Last edited by pahanorlando; Jan 7, 2025 at 01:17 PM.




> there is only one thing that does both rattle + causes fault: It is an unlocked VVT Gear.
> Oily CPS only triggers code but can not rattle!
> The proven wisdom is not to delay repairs because next notch includes the whole set of camshaft/reluctor.
> To PREVENT wearing out VVT Lock pins:
do not drive around on low oil pressure that locks/unlocks VVT endlessly.

Last edited by CaliBenzDriver; Jan 7, 2025 at 05:17 PM.
do not drive around on low oil pressure that locks/unlocks VVT endlessly.
(80k mile ML550 W278) How do you ensure no low oil pressure beyond regular oil changes with quality oil? Ive always used Moble 1, changes right on schedule, filter replacement done half way between each oil change as additional precaution, but I think I have a VVT adjuster going bad (and my CPS sensors leaking...replacing those next week). I was advised to change to Motul oil, but if damage has been done, there is no reversing it at this point.
Additional question. Im changing filter every 5k miles (precaution) and oil at 10k intervals according to manual. Dealer told me when I purchased it new, that since it took a hefty 9 qts, 10k oil changes were frequent enough. Should the oil changes have really been done more frequently? Too late now and more frequent changes not really gonna help me? I love this car after 13 years of ownership, but dont want it to become a money pit.




do not drive around on low oil pressure that locks/unlocks VVT endlessly.
(80k mile ML550 W278) How do you ensure no low oil pressure beyond regular oil changes with quality oil? Ive always used Moble 1, changes right on schedule, filter replacement done half way between each oil change as additional precaution, but I think I have a VVT adjuster going bad (and my CPS sensors leaking...replacing those next week). I was advised to change to Motul oil, but if damage has been done, there is no reversing it at this point.
Additional question. Im changing filter every 5k miles (precaution) and oil at 10k intervals according to manual. Dealer told me when I purchased it new, that since it took a hefty 9 qts, 10k oil changes were frequent enough. Should the oil changes have really been done more frequently? Too late now and more frequent changes not really gonna help me? I love this car after 13 years of ownership, but dont want it to become a money pit.
Even the unlocked VVT issue may be cancelled while running effective oil pressure.
Of course good engine parts help normal performance, particularly true for the weak chain tensioners.
Without too many changes you can upgrade your engine to an "MB Approved" MOTUL 5W40 or equivalent replaced between 3 to 5kMi.
When oil ages it shears viscosity polymers to become lower grade... it's up to you to renew oil for protective qualities you need.
In addition Mercedes use a solenoid to lower oil pressure under 3500.Rpm - This topic is debated here...
Last edited by CaliBenzDriver; Jan 8, 2025 at 05:51 PM.
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regardless, since it’s been running with low oiling, that is the likely reason the adjusters (if that’s the real issue) have worn, but have made it to a decent mileage.
lastly, there is evidence of the tone rings on the camshaft’s spinning out of position, causing a camshaft adjustment issue so you will want to look into checking your timing by looking through the camshaft sensor ports.
you can do the mods as Cali suggests to get some better oiling pressure now and see if anything changes with your camshaft adjustment angles. Rattle may or may not be resolved dependent on you answer to the first questions.
I was working on other stuff on ML350. This week was first of me actually using the car to go to places (before it was post purchase fixing stuff up and do short test driving).
Still, in probably a month or so, I did not hear engine rattle on startup at all, so hopefully issue is not adjusters.
By looking at timing covers, they look really dry, but I know the oil pan is pretty wet with oil. That's another issue I'll have to deal with eventually.
But I'll try to take a short video of timing covers and cam sensors connectors hopefully this week.
P.S. To answer last question. I did not change any of that as I just bought the vehicle 2 months ago with 131k miles on it.




I was working on other stuff on ML350. This week was first of me actually using the car to go to places (before it was post purchase fixing stuff up and do short test driving).
Still, in probably a month or so, I did not hear engine rattle on startup at all, so hopefully issue is not adjusters.
By looking at timing covers, they look really dry, but I know the oil pan is pretty wet with oil. That's another issue I'll have to deal with eventually.
But I'll try to take a short video of timing covers and cam sensors connectors hopefully this week.
P.S. To answer last question. I did not change any of that as I just bought the vehicle 2 months ago with 131k miles on it.




Old oil drains down quickly from the upper engine VVT gears + tensioners.
So when the engine starts up, the camshafts timings remain poor until oil pressure builds up 10 seconds later.
This is witnessed by how long it takes the ECU to ramp down Rpm to idle as soon as camshafts get under control.

Last edited by CaliBenzDriver; Feb 13, 2025 at 05:37 AM.
Just checked 3 out of 4 of those magnetic sensor connectors. They all seem to be dry. Couldn't get to the last one as it was blocked by air filter housing. I'll have to google on how to remove the housing lol
I did notice the hose that is connected to throttle body (the clamp) was loose, which probably solves my issue of rough idle. Hopefully I can use regular traditional clamps instead of those
Attached is video I took of 3 out of 4 connectors.




The adjusters can be checked manually by rotating the engine and listening for the "click".
You can try that test with timing covers on, the " click" should be obvious enough.
Last edited by JCM_MB; Feb 16, 2025 at 09:55 AM.




