m272 engine noise can anyone tell me what it is?
 

2006 e350
I looked at some other videos on youtube and there aren't any definite answers. people just suggesting many things that could be

I feel like its coming from the pass side head.

heres another video its hard to caprute since its not very evident at all times.


I don't think its anything to do with the block since it does not get louder on cold start. its exactly same regardless of engine temp

the air pump is very loud on startup though I don't know why or if its normal or not

Sounds like a lifter tick.

is that common? should i do anything about it? or is it ok to drive like this?

115000 got it with balance shaft codes fixed balance shaft and I belive the noise show up after I put everything back together. but I cant say for sure because I only drove it once to bring home and pulled the motor right away.
so Im not realy sure if it was there or not

That's a bad lifter

is it safe to drive like this?

is it lifter or cam gear?
can it be bad Camshaft Adjuster Magnet?

yes I did balance shaft oil pump both chains and all chain guides and tensioner

I installed the original cam sensors and magnets for now so new ones don't get any crap in them during the initial run
could one of the magnets be bad?

but I did follow the manual for whatever I found and I did use oem parts for everything


there are no codes. I scanned multiple times and only code was for driver side wheel sensor.
which im checking right now to see if its dirty or damaged.

it has good acceleration etc engine feels strong and noise doesn't seem to be affected by anything like temp or revs. it stays same volume and doesn't get louder or quieter under any conditions

I mean I cant really hear it when I rev up the motor so it either goes away or just blends in with the other noise but during idle it is constantly same noise cold or hot.


I am using 0w-40 mobil1 European from Walmart already
to be honest the engine is rather clean. I did not see any buildup looks like it was a healthy motor and car is excellent condition otherwise.

say I add one of those oil additives (whatever its called that's allover youtube now ) and noise goes away is that a sign of bad lifter for sure?

should I try simple zddp additive for now and see if it helps?

i got the magnets with the balance shaft kit
everything i got is oem i dont know if the ones that came with the car were oem or not but looks like they were.
and sensors as well and one extra filter.
will try to replace it
i didnt see any damage on cam lobes or cam gears
and i did install new timing plates? or whatever the disk that goes on the cam gears.

once i replace the magnets do i have to take it to dealer to recalibrate anything or the car does it automatically?

no I reused the old magnets for the break in period.just in case there are leftovers of any junk from the startup so it doesn't destroy new ones.

I reused spark plugs magnets and sensors for first few 100 miles. its been about 300 miles now I put new plugs in and about to replace the oil filter now and was thinking of just keeping the new ones until old ones go out. or just include them with the car when I sell

are the magnets calibrated each one individually or can I swap them around and see if something changes?

I mean would a bad magnet even cause that sound?

Ok I understand more now. Here is what I would do.

The cam adjuster magnets are known problems anyways and not expensive so order the kit with oil housing gasket and replace. Because you are pulling that off I would also bite the bullet and remove the cam covers and spin the engine at crank and inspect. No need to replace the cam sensors but change the o rings if you do or if oil is leaking. You aren’t throwing timing codes but you can check timing again here too. Make sure you apply gasket bead correctly and torque bolts at spec on cam covers.

Then report back.

well I did just finish putting everything together. I didn't see any damage on cam gear and used a pin when took it off and put it back.

I will start with replacing the magnet in question
how would I tell the valve tick vs piston sleeve bang?

Hello raverx3m,
I own a S350 with the M272 engine. I bought the car with a broken engine. I also replaced the balanceshaft, timing chain, chain tensioner, chain gliders etc. myself. I also found that my engine was clogged up with sludge and I about half of the hydraulic lifters were broken and replaced all of them. I reassembled the engine and torqued everything to spec. After driving for about 2000km without any problem yesterday I took the car to Germany and drove it at 200km/hr. No I am also experiencing the knock same as you do (did). I was wondering if you found a solution to the problem.

By the sounds of it it knocks once every engine rotation. If it would be a cam shaft timing issue I would expect all valves to make a noise that would be 8 times each rev. I intent to check the engine with a stethoscope today to see if I can pin point the location of the knock.

Please let me know if you found a solution.
Kind regards,
Frank

why is everyone calling them lifters? Lifters are on pushrod motors with cam in block. They are cam followers/buckets
Anyway, we have seen many 272 motors that are somewhat noisy like that, run fine and do not throw any codes? maintain oil level with proper oil and call it good, you could be chasing those noises for ever and tear into your motor only to find that upon re-assembly the noise persists?

my 2 cents

BTW, just curios how long can one drive with the lifters/cam followers noise before any problems develop? The "lifter" is just a piece of solid metal that the cam uses to push the valve stem, plus a hydraulic "spring" on the top of it, which follows the cam. Once the hydraulic part collapses (bad or dirty oil typically), the lifter becomes shorter and does not make a constant contact with the cam - the cam slams it only at the time of opening the valve - this is the noise we are hearing. So the stem and the cam will wear more, but since it's all lubricated I would expect that one can drive the car for tens of thousands of miles like that before any noticeable wear. Or am I missing something? Can the cam fail to fully open the valve for any reason?

I would assume that clogging up or destruction of plastic oil feed pipes like we had on the 1980s mercedes V8 is not a problem on the modern engines with a reasonable oil changes procedure?

Any deeper insight into the problem is appreciated, thanks! (Some people would say stop driving because you can destroy engine, others will say you can drive forever, I think both of those extremes are wrong - where is the middle truth?)