OIL PUMP WHINE REVISITED
 

Thought I would share some 'more' insight to our wonderful oil pump whine on the m113 engine. Decided that that would be a priority to find a possible culprit to this issue that so many have.
Pulled engine and trans out last weekend to do a quick freshen up and up date a few things, engine has 70,000 miles....installing ARP head studs,rod bolts,bearings,opening ring gaps yada yada. Engine was mint inside with only a few things causing small issues.
1 The oil pump chain hitting the front cover...gives a little 'tap tap tap' at idle do to the tensionor being weak and puts marks in the cover. Easy fix.
2 The oil pump intake o-ring was for sure getting hard. A few people talked on that subject a while back and where very concerned but there are really very few reports on failures.
3 After disecting the oil pump there is nothing to report...looks like new which is very dissapointing. Not that I want to see anything bad but....something !!
So I will throw a new pump in for the hell of it but don't have any hope for a 'very' quiet engine.These cars have been doing this for a long time and the oil itself plays a huge roll in noise.

I can't even get myself to care about the noises this car makes I have bigger fish to fry with it constantly lol

LOL Is it not the noisiest strongest built,most powerfull for it's time AMG engine you have ever heard ? When I first bought my car I thought to myself...this is a Mercedes ? My Crown Vic with 230,000 miles is far more quiet than this thing. LOL But that's how they are.

Did you replace the spring for the oil chain? That's the biggest offender in my car, I found shavings and I can hear it... I don't have the means to pull the engine out at this time since I don't have a garage, but when I do it'll be for that...

Do you wrench for a living? Or is this just a hobby to you

Yes all wearable parts. Timing chain ,rail's, oil pump chain and tensioner and oil pump.
I am a mechanic by trade.....transmission rebuilder, but this is a hobby. Love doing this stuff and going faster !!! LOL

people (including me at first) just assume the noise is the supercharger lol...

I thought it was that secondary air injection pump at first. I changed my oil to Liqui Moly and it never came back. Only happens with Mobil 1.

Add MOS2 or Ceratec, or any good additive and it goes away as well.

LIQUI HELPS FOR SURE. BIZOL WAS THE BEST FOR ME BUT THEY STOPPED MAKING IT, 0W-40.

Yeah, I just figured that out the other day. I went to reorder some Bizol and can't find it anywhere. I'm doing LiquiMoly this time.

I am curious if new tighter bearings will have any effect on noise as the pump pressure internally will be a little different.Will be a while before she is in and running do to some changes with exhaust and stuff. Spent the night stretching rod bolts and forgot how slooowww of a process it is......but well worth it.

BC928 no....same rings but gaped a little wider.Engine bores,rings and pistons are absolutely mint so not messing with it. I have to give a thanks to Tony at Race IQ for a perfect tune. piston tops and valves perfectly clean although it took me many tunes to get perfection. LOL.

Joe the Liqui Moly is close to the Bizol as far as noise. It's crazy how they just stopped making it and no one anywhere carries it !!

which LiquiMoly are you using? my car is not far from a service so i might as well give it a try.

The regular 0w-40. When I race I use the 5w-40 which is a little more noisy.

Hello & Good morning!
I've starting to investigate this ticking noise myself and have heard a few times now that it 'could be the oil pump chain relaxing and hitting the timing case' you're pretty much the first person I've heard outright say that it is an issue!
Could you provide some insight on the job? pics if you have em! i'm wondering if this can be fixed without taking the engine out of the car. I heard the hardest part is resealing the oil pan - can you comment on any of this?

I have the parts to install an oil pressure gauge, did you end up replacing your oil pump? did the noise/ oil pressure get any better?
https://www.weistec.com/oil-pump-set-m113k.html

Thanks! - Ryan

Some one did do a fix with the engine in the car but it was a lot of work. I don't remember who did it.
My concern was the whine sound, not the ticking and yes a new pump installed and made no difference with the whine, oil pressure was the same as well.
The oil brand is what really made a huge difference for me.

Thanks for the reply, so just to confirm - the ticking went away completely for you with the timing cover issue? did you just replace the wear components & dremel the case back a bit?
Im running Liqui Moli right now too, ticking drives me insane!

Yes replaced chain , tensioner and worked the cover over a little.

Is the whine from the oil pump or transmission fluid pump? I only hear it when I drive and no matter how long I let my car warm up and idle I still hear it when I start to drive but goes away after a minute.

I can not diag your car from the internet but would guess it is the oil pump. You can get a mechanic to look at it for you and determine where the noise is coming from. Maybe a pulley ??

the oil pump in the E/CLS 55 is a 2 stage pump which is the main reason for the noise, the S/SL/CL have a different oil pump design since they don't have oil pans which need to fit around the subframe

i've also noticed that it's noisiest right after an oil change if you put all 9 quarts in, but as a bit of oil slowly burns off (or leaks out lol) the pump starts to quiet down... the manual says the oil capacity is exactly 9.0 quarts, since not all of the oil drains when you do a change adding a full 9 quarts would theoretically mean there's now a bit too much oil, so now i put about 8.75 quarts in and it's pretty quiet for the most part

1i0k miles here and no whine. Well there *was*, but it was the AC compressor.

well mystery solved

the startup whine is the coolest thing on these cars, if only it could be made louder when warm...

I think it sucks....has no comparison to a supercharger whine or anything good for that matter......more like a bad power steering pump noise !! It is what it is. Thankfully I found an oil that shuts it up a lot so that's a blessing .

I slightly “Ported” the oil pump. Smoothed some of the casting transitions. I guess we will see if that makes a difference.

Hey I ported mine as well ! Smoothed out all the transitions like you said and removed any casting flash. Make sure you turn the gears as you snug up the pump. The housing can bias the gears a little when not perfectly centered. At first I just tightened the bolts and noticed a very slight bind, then loosened them and snugged them up while rotating the main gear.