krazzdav

Can you adjust the valves on the 3.2L M112 in a C320? Does anyone have the procedure and gap for the valve adjustment if so? If not what are the parts that would wear out? I have looked and searched hi and low to no avail :P

I am thinking that there might be an adjustable tip where the rocker arm meets the cam. EPC doesn't have enough details to know either way--just shows the lifter (hydraulic element) washer and rocker arms. If I had to replace all the washers and lifters would be $252 just for those on the one side. Does the official MB Star Service Manual have all the details to replace them if needed? -- cam/crank alignment, shaft torque spec etc

My passenger side sounds like it needs adjusting and only has 100k

mleskovar

No.

raceral

raceral

This is what it looks like in there... My car had 105k miles when this pic was took. Mobil one every 10 miles... clean as a pin.... these are some serious rocker arms... looks like racing parts

Glyn M Ruck

The engine uses zero lash hydraulic lifters.

Yes ~ they are bomb proof. Very robust design.

RobertG

Do you have correct oil in there and oil filter?
when does it make noise?

Glyn M Ruck

If you don't use approved oils with very good HTHS (high temperature high shear) characteristics you can suffer valvetrain wear. These M112 engines are good for 1 million Km's if serviced to the book.

C230 Sport Coup

OK, just slightly OT but I've been getting some noise on my #4 valvetrain on my M111 4 banger. Been meaning to post, but since we're essentially on the subject oh great one...

Click click click. Comes and goes.
My engine doesn't look nearly so clean. Not sure why.
I did run some non approved oils for a while, still it was
not cheap and was still synth, just Valvoline, and the Pennzoil Plat.
But I changed it every 7K to compensate and after a few oil changes with that, went back to Mobil 1.

Could I have a blocked oil passage? Or a lazy hydraulic lifter?

Glyn M Ruck

It could be either. Lazy lifter is most likely. Could also be a slightly worn lifter. They rotate & the clearance might vary slightly until the hydraulics take it back to zero lash.

krazzdav

Thank you for everyone's input and raceral for the pic!!

Unfortunately I bought the car used just under 90k miles and it has made the same noise since I bought it a little over a year ago. Since then yes I use the correct oil and MB filter and it makes the noise all the time and varies with engine speed as well just like a loose lifter so must have one or two that collapsed.

What's the torque spec for the rocker shaft? I have to change the valve cover gasket so might as well check that too (doubt it will be loose or fix anything though)

krazzdav

Can someone post the procedure from the MB service manual for replacing the cam? Specifically i need the torque for the rocker shafts and if there is any special procedure needed changing the lifters (ie pre soak or pump up)

I confirmed it is the rear lifters on the drivers side causing the noise. Here is a vid...the lighter tap is from the injectors.

krazzdav

Well had to get my own WIS since nobody replied-- but it was needed anyhow

FYI all the bolts for the cam bearing retainer need to be replaced as well, cams need held in place and it comes out as an assembly minus the cams it appears. If you do replace the cams they need to be replaced as a set also.

tasmit99

Since they are hydraulic valves my guess would be no you can't adjust them. They are basically self adjusting.

tischlerbmw21

These engines use hydraulic lifters that sit inside the rockers, they are self adjusting based of hydraulic oil pressure. I have a noisy lifter on my W211 E500 I just need to find out exactly which one is.

jaebber

I have a 2006 c230 with 2.5lt v6 It has only seen mobil1 every 7000 kms and the lifters tick lick crazy now after i used a lubrifiner oil filter. I have tried everything thing I can for oil additive and now looking for advice to change them. I am a mechanic and have no luck loading the WIS on my computer?? Is there anybody that can direct me to what tools i need to hold cam without wrecking the cam phazer gear on the front of the cam. What ever happened to paper book service manuals anyway?
I also need advise on anything I may need when I change the lifters out. Please and Thank You

krazzdav

unfortunately jaebber you have the M272 motor while mine was the M112 so can't give you any advice other than to make sure that is your problem. I would recommend starting your own thread since your engine is different.

For my vehicle I changed the lifters/cam followers for what I thought was noise from my lifters but it did not make any difference so wasted all that time and money. Good thing I can wrench and shopped around for what I needed so wasn't too expensive--more annoyed.

For my M112 I changed-(only did one side that I thought the noise was coming from and this is from memory from a couple years ago)
tensioner (forgot where I got it--maybe rockauto)
cylinder head bolts for cam bearing to head -- 14 OEM from ebay for about $15
INA cam followers purchased from importec.com for about $75 for 9 (3 exhaust/6 intake)
and purchased Baum Tools Camshaft Alignment Kit for the M112/M113 engines PN# B112-0001K for only about $50 off of ebay.

I have since purchased engine ears so I can see where exactly the noise is coming from but haven't been motivated yet to isolate it further.

trong_l

Hello krazzdav, I have the same problem with my 04 C240with 110K miles, it is on the driver side bank. Everybody I've talked to thought it was the lifter(s) went bad, one German-car mechanic did some diagnostics and pin point it was the two rear cylinders on that bank, I refused his estimate of anywhere between $700-$1000. Brought it home I have replaced all nine - 6 intake and 3 exhaust- hydraulic valve lifters and the tapping noise did not go away. I purchased a set of rocker arm assembly on ebay -came off a 2004 SLK320 with 80K miles- and put it in, same noise. At this point I kind of give up on the problem. BTW, the car runs fine with no oil consumption and has plenty of power. Let me know what you find out with your car.

s211_320

Hello,
anyone knows what it is? I have the same problem. Ticking knocking under load.
I change all valve lifters, but it is like it was before..

Eugene A Boxley

I've had the same ticking noises in my m272 engine (twice). Both very similar noises... One case was a broken swirl flap in my intake manifold, which I replaced. A month later I found the ticking to be a bad fuel injector. I'm quite positive that the cam followers will make a distinctive noise and then usually just stop. Problem is usually that the tappet collapsed, in which you won't hear tapping noises for long, "but" you'll eventually get P030X codes (random misfires) on affected cylinders. This (misfires) "always" follows a collapsed hydraulic valve lifter.

5GreenMachine5

[
Anybody replaced the knock sensors?


QUOTE=krazzdav;5351465]Can you adjust the valves on the 3.2L M112 in a C320? Does anyone have the procedure and gap for the valve adjustment if so? If not what are the parts that would wear out? I have looked and searched hi and low to no avail :P

I am thinking that there might be an adjustable tip where the rocker arm meets the cam. EPC doesn't have enough details to know either way--just shows the lifter (hydraulic element) washer and rocker arms. If I had to replace all the washers and lifters would be $252 just for those on the one side. Does the official MB Star Service Manual have all the details to replace them if needed? -- cam/crank alignment, shaft torque spec etc

My passenger side sounds like it needs adjusting and only has 100k [/QUOTE]
C240 knocking

5GreenMachine5

Has anybody changed or checked the knock sensors under the intake?