Hey Guys,
New one here, a w164 ML63 owner, however recently swapped out a motor from C63 (due to new bolts and cams).
There is a difference in subframe config between two platforms w164/w204 we had to swap out oil pump and sump from w164 original engine, while doing it we didn`t find anything suspicious on the donor`s lower end. The project went fine we`ve fired up engine it ran smoothly after choking out all gunk and priming out litfters. Unfortunately happiness didn`t last long ... after couple of weeks driving I started to notice a strange noise, that was coming mainly within couple of minutes after a cold start. The location was somewhere in the oil pan area, we bridged the car and located the noise closer to the bell housing, but definitely not inside it, thus not torque converter !So far oil is clean after two premature changes, no metal shavings. I`m a bit frustrated, maybe somebody who has more experience with M156 can make couple of good guesses. While it is cold and oil is thick you hardly hear it , further it develops to louder state and almost goes away when hot.
Thanks in advance,

Dany

 

What's your oil level? Almost sounds like it's over full and the crank is splashing around.

 

Does the noise increase/decrease with RPMs?

Could be overfilled oil. Did you remember to change the dipstick back to the ML version to account for the different pan shape?

 

Beat me to it, this was going to be my recommendation.

 

^^Easiest way to confirm that is to look for foamy oil on the stick.

I know you said it wasn’t TC, but:

It sounds like loose flex plate to crank bolts, especially if old ones were reused. Does the noise go away when you put the trans into gear?

That’s also easy enough to check with a pry bar through the inspection port underneath. Try to wiggle it back and forth. Make any noise?

How does the sound change with a gentle rev?

 

Thanks for the answer, Gents!

It is half level - thus in the middle of the dipstick, while measuring cold engine after start ( engine not running ) . Deepstick was swapped out indeed, W204 has totally different sump and two contour pump, thus dipstick is installed closer to the bell housing, while w164 has it in the front. when you raise RPM the noise becomes less obvious, might have something to do with other noises coming into the scene. Anyhow, this particular one is not getting any louder.
For me it also sounds like something is splashing in the oil , maybe a leak in the pump , like a sharp spray entering the puddle of oil ???
As far as foamy oil, you don`t see it on the dipstick , tube shape ( the one that accommodates the dipstick itself ) is quite wiggly , maybe it wipes all the foam out. Another option is to try running it on an empty sump, just for a sec, to see the difference, but it is quite a risky business considering camshaft related specifics of this engine!


The Machinist, I will try to check your theory, might be quite true, cause I am also experiencing hardly noticeable vibration while cold and driving 20-30 mph.

 

If you have an oil leak between the pump and the block Somewhere causing a high pressure stream of oil into the sump, this would also cause the oil to foam.

You’d also have low oil pressure issues, especially noticeable at a hot idle when the pressure is lowest. The top end would start to make noise as the lifters collapse.

I would not recommend running the engine without oil in the sump.


Foamy oil could also be seen through the oil fill hole on the valve cover. It would appear cloudy.

 

The M156 does not have an oil pressure sensor. There is a port in the oil filter housing that you can use to add one though.

 

I need to do this

 

Im working on a kit!!! (Oil pressure gauge not included...)

 

What sort of kit?

All you need is a low profile banjo, 10" of -3AN line (which is brake hose) and an adapter from -3AN to the pressure sensor you use.

https://mbworld.org/forums/m-class-w...ml63-m156.html

 

Much larger than -3an.

I’m going with -8AN, and there’s plenty of clearance for a straight fitting into a 90 degree swivel on the end of a hose.

I am planning on putting together a parts list after I’ve tested it for an oil pressure port, an Accusump for prelube purposes, and a check valve with a Y split to back feed each cylinder head externally with high volume oil via -6AN lines. The first iteration has a fairly spendy parts list, but Earls AN fittings aren’t cheap, and I’d rather get those than Chinese made ones, which aren’t much cheaper.

That way I can run 20W50 oil in the hundred degree heat without worrying about starving the heads for volume when cold starting.

 

You're going to use the port on the oil filter housing as a feed? If so, I don't think you can do that. From what I remember it's designed to be capped off by a plug or sensor. Using it to branch oil flow could cause major oil feed issues.

 

Not really. Think of it this way:

Ever taken a luxurious warm shower only to have someone flush a toilet in some other part of the house and wind up looking like a boiled lobster?

Thats what I’m preventing. The valve train is the guy in the shower. Everytime the adjusters make a move, they starve what little volume the cams and lifters do get from the main gallery.

Im supplying the shower with cold water from both ends of the house. Once the pressure differential is equalized, there will be zero net flow through the external auxiliary feed lines.

I’m not running the oil lines up into the valve cover uncapped for the oil to spray everywhere. THAT would cause oil flow problems, just like running an oil feed line to a turbo with no restrictor orifice.

I am running them up to the end of the same gallery that supplies the lifters and the camshafts with oil, but from the other end, with a check valve to prevent back flow.

My theory on the root cause of most top end issues with the M156 relates to poor oil supply mixed with a dash of lousy metallurgy.

The entire cylinder head on each side is supplied with oil from the main gallery in the valley of the block behind the oil filter, via a tiny port machined into the deck of the block. The dual adjusters, dual cams, and 16 lifters on each side demand more oil than can be supplied through the small orifice.

This can be proven with an oil pressure gauge attached to the gallery port on the back of the head, and with another one attached to the port on the oil filter housing. I’d bet a good chunk that there is a significant pressure differential.

This, combined with the desire to reduce parasitic drag is why AMG recommends oil with the same viscosity as helium, and that is the only reason that higher viscosity oils (like the liquimoly 10W40 with MoS2 already in the oil) do not meet the AMG oil spec. 222.something? Can’t remember. Whatever it is.

Seeing as I am not racing my car on a track trying to squeeze every last rev out of my engine to shave .006seconds from one lap, parasitic drag of engine oil does not register on a list of my concerns. I may end up losing a mile or two to the gallon. Oh well...

 

I fully understand the solution you are attempting to resolve but that's not what I was asking.

You replied to a quote chain about using the port in the oil filter housing for a pressure sensor. I am just saying to verify you can use that as the oil source for your project if that was your intention.

 

I get it now. Yes, that is my intention.

Either that, or I pay for one of those Weistec billet filter caps, drill and tap for -8ORB and pull the supply from there.

Most of these caps are there simply to cap off the end of a passage where cross drilling took place. I don’t believe that AMG had any ultimate intention for that port, other than to cap it off. Same with the port on the back of the heads. It’s just where they were gun drilled.

Ideally, I would like to pull supply from the main gallery in the block somewhere, but I am not aware of an accessible location to do this.

 

From what I recall it's a specifically designed oil pressure port. Watch the Tasos video in the link I posted where he shows the same port on 32 other merc oil filter housings.


If you use that as a feed with a large diameter line, it could drastically drop oil pressure to important components when it's filling the Accusump body.

 

Truth of the matter is, the line could be -16AN and make little difference, as it is being fed by an M12 fitting which has maybe an 8mm size orifice through the middle. 8mm is in between -4 and -6 for size comparison.


Ive seen this video, which is one of the reasons this plan exists.

The initial fill is accomplished by preloading the Accusump air side to 80PSI. While the engine is running and with the valve open the air is slowly bled down to zero. Once the pressure reaches zero, the valve is closed, the engine shut down, and the air brought back up to 80 PSI.

The way around the pressure drop while filling the Accusump is to use the solenoid valve. Leave it closed during the fill phase.


I have a very similar system on my B6 S4. It also uses the factory oil pressure port location.

The solenoid valve acts like a check valve for the Accusump when closed, it will allow it to fill slowly, while not letting anything out.

I had similar concerns when I first installed it on the Audi. It was never an issue. That Accusump in the Audi is hidden in the trunk where the optional 6 disc CD changer is supposed to go. It has 3/4” hydraulic hose running in Adele clamps on factory studs all the way up to the vicinity of the transmission mount where it drops down to 1/2” hose.


Typical operation of the Accusump for prelube on a start is to turn the ignition on, open the solenoid valve, wait for the oil pressure to climb, once it peaks and starts to drop, close the solenoid and start the engine.

During normal driving, the Accusump remains closed to the rest of the circuit, unless the pressure of the circuit exceeds that of the Accusump, in which case the Accusump will rise in pressure to reach the system peak.


The adapters I made for the project. The one on the right adapts the M24x1.5 port to 1/4NPT—6JIC. The part on the left has a 1/8NPT port for an oil pressure gauge as well as an M10x1.0 port for the OE pressure sender, with a pass through on either end for a hydraulic hose to the Accusump.




Accusump in the trunk of the S4.



There is access to the main gallery on the M156 behind the flex plate in the bell housing where the big block off plug is, but getting a hose out of there would be labor intensive to say the least.

 

Wow! Man, if you ask me ... I think you are over complicating, you could just use boron nitride in your oil ( liqui moly molygen 10w40 ) it will add some elasticity to the engine, plus will plaque all micro scuffs on contact surfaces.
The M156 mostly went bad due to high service intervals and low additive oils recommended.

 

Ive undoubtedly gone waaaay off topic. The subject of engine oil in this forum is about as productive as a discussion about politics or religion.

As I am sure most will point out, Liquimoly 10W40 with the MoS2 additive does not meet the Mercedes spec.
Molybdenum Disulfide is a different compound than Cubic Boron Nitride. I would not recommend running any CBN suspended in your oil.

However, the Moly additive can be purchased and added to oils that do meet the spec.

The high service intervals certainly didn’t help, but the root cause of the top end issues is seated squarely in the metallurgy.

Search for threads created by myself or Go Team. They will be enlightening.

 

Who cares about Mercedes spec as soon as the car is off the warranty !?
What`s the problem with boron nitride ( I`m referring to hexagonal boron nitride) in LM Molygen ? it is basically the same ceratec the one Liqui Moly produces themselves, I didn`t see any restrictions on using that one with their molygen lineup

 

Small update on the matter.

this week tested following :

1. Oil pressure at idle, 1000, 2000, 3000 Rpm ( see videos below )
2. Checked / changed oil filter 3000 miles no metal shavings found
3. De-coupling torque converter was not a great success : there is not enough clearance between the flexplate and the converter. Pop-rivets that hold crown gear on the flexplate are catching the converter attachment points, therefore running engine in such manner is not a great idea.
4. Flexplate seems healthy, no cracks found during the inspection . BTW it is only accessible thru the lower inspection hatch, detaching alternator will not do any good.





Considering the oil pressure numbers, I strongly doubt that engine might be the cause.
We are slowly coming to the conclusion, that TC might be the source of that strange noise.
I guess I would have to drop the tranny down and get the TC cut open.

 

Did you end up finding a cause or solution to the sound?

 

Yup, it is normal. Platform (w164-251) specific oil pump noise when cold. I've spoken and inspected 5 ml63 and ask other owners over the internet, everyone does it.
So no worries there.

 

I'm sorry to dig up this old topic, but I've recently noticed that the M156 bearing clearance is at 0.07-0.09mm, with a crankshaft journal of 70mm. Would 40-viscosity engine oil be too thin, leading to a loss of oil pressure? If we use a higher viscosity oil, would the oil pressure be maintained better?