OM642 Oil change procedure
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
OM642 Oil change procedure
Hi Gents.
My Jeep has the OM642 unit. Everything I read about this Engine in the Jeep says I MUST put half the Oil down the filter housing to 'coat the bearings'.
Is this just Jeep related Bull poop or has it a basis in reality? I have never read of anything official from either Mercedes or Jeep to support it.
Do you guys put half your oil down the filter housing?
Any opinions welcome.
Many thanks.
My Jeep has the OM642 unit. Everything I read about this Engine in the Jeep says I MUST put half the Oil down the filter housing to 'coat the bearings'.
Is this just Jeep related Bull poop or has it a basis in reality? I have never read of anything official from either Mercedes or Jeep to support it.
Do you guys put half your oil down the filter housing?
Any opinions welcome.
Many thanks.
Member
Joined: Sep 2017
Posts: 173
Likes: 25
From: UK
Mercedes R320L CDI 4MATIC 2007
Hi Gents.
My Jeep has the OM642 unit. Everything I read about this Engine in the Jeep says I MUST put half the Oil down the filter housing to 'coat the bearings'.
Is this just Jeep related Bull poop or has it a basis in reality? I have never read of anything official from either Mercedes or Jeep to support it.
Do you guys put half your oil down the filter housing?
Any opinions welcome.
Many thanks.
My Jeep has the OM642 unit. Everything I read about this Engine in the Jeep says I MUST put half the Oil down the filter housing to 'coat the bearings'.
Is this just Jeep related Bull poop or has it a basis in reality? I have never read of anything official from either Mercedes or Jeep to support it.
Do you guys put half your oil down the filter housing?
Any opinions welcome.
Many thanks.
Maybe this instruction is when you are adding oil for the first time to a brand new engine?
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
Thanks for helping.
No it applies to oil changes too. If you watch every Jeep oil change on 'you tube' or any oil change post on a Jeep forum they all say the same thing.' Put some oil down the filter housing, it's important'.
I wish I could get a definitive answer hence I came here to the 'home' of the manufacturer
.Great engine though. Pulls like a Train even with two tons of Grand Cherokee.
Many thanks.
Last edited by Jeep driver; Apr 24, 2020 at 08:16 AM.
Member
Joined: Sep 2017
Posts: 173
Likes: 25
From: UK
Mercedes R320L CDI 4MATIC 2007
Hi
Thanks for helping.
No it applies to oil changes too. If you watch every Jeep oil change on 'you tube' or any oil change post on a Jeep forum they all say the same thing.' Put some oil down the filter housing, it's important'.
I wish I could get a definitive answer hence I came here to the 'home' of the manufacturer.
Great engine though. Pulls like a Train even with two tons of Grand Cherokee.
Many thanks.
Thanks for helping.
No it applies to oil changes too. If you watch every Jeep oil change on 'you tube' or any oil change post on a Jeep forum they all say the same thing.' Put some oil down the filter housing, it's important'.
I wish I could get a definitive answer hence I came here to the 'home' of the manufacturer
.Great engine though. Pulls like a Train even with two tons of Grand Cherokee.
Many thanks.
I am attaching the instruction to which i am referring.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
Must be Jeep thing as I never heard about bearings coating on Mercedes.
Synthetic oil do have lot of Molybdenum, who makes semi-permanent coating, who give you good lubrication even with no oil.
Than fact is that oil filter housing is much more convenient for filling than the top hole.
Synthetic oil do have lot of Molybdenum, who makes semi-permanent coating, who give you good lubrication even with no oil.
Than fact is that oil filter housing is much more convenient for filling than the top hole.
Senior Member
Joined: Jul 2017
Posts: 487
Likes: 114
From: DFW, TX
Ml350 bluetec
Not required, it's bull poop being spread by Jeep group. Don't see how pouring oil into the filter housing would help the bearings on the crank shaft. The oil filter housing is on the front driver side of the engine, the crank shaft is in the middle and runs front to back. This is the same rumour going around that one should pre-fill oil filters when changing oil in other forums.....
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
With its 2 quarts capacity , the oil pump will spend several seconds to fill the filter before oil will go to engine.
So I am filling up those filters before installation.
MB has top-mounted filters, so you don't have this choice, but than filters have like a cup capacity, so fill up is much shorter.
Trending Topics
MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
Likes: 153
From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
I've always pre-filled my oil filters when they were mounted where God intended; underneath facing up. Before I started to do so, sometimes I would hear the engine clatter a bit on start-up 'till the oil filled the filter and reached the lifters etc. I've experienced it first hand. Eyes on the oil pressure gauge, the clatter would disappear the second the gauge jumped back up. Rumour for some, fact for others...
I dunno about pouring oil down the oil filter housing, though I sorta see the logic of it. If that passage has gone dry due to the oil-filter and oil change, then the oil has to fill the new filter and also travel down the oil passage to get to the oil circuits. Having said that, I've never heard the MB clatter following an oil change. I still try to pre-soak the new filter in the hope that it will get the oil going thru the circuit quicker, but I don't know what difference that makes, if any.
I dunno about pouring oil down the oil filter housing, though I sorta see the logic of it. If that passage has gone dry due to the oil-filter and oil change, then the oil has to fill the new filter and also travel down the oil passage to get to the oil circuits. Having said that, I've never heard the MB clatter following an oil change. I still try to pre-soak the new filter in the hope that it will get the oil going thru the circuit quicker, but I don't know what difference that makes, if any.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
Hi Virgisr.
Thanks for the pdf. It would seem that Mercedes never thought it important enough to mention.
I do not know what variation of engine I have and not sure how to find out. I looked at the factory build sheet and it just says OM642.
It has a 9.5 litre oil capacity unlike the one on your PDF that states 8.5 litres.
Interesting too that the Jeep 722.6 uses ATF+4 and not the Merc' spec.
Thanks for everyone helping.
I cut and paste this from a Jeep forum. The guy 'merlin' is a Jeep mastertech so does at least give some credence to his words. Older post but still relevant.
Opinions please?
https://www.jeepforum.com/forum/f67/...-grand-493293/
Thanks.
Thanks for the pdf. It would seem that Mercedes never thought it important enough to mention.
I do not know what variation of engine I have and not sure how to find out. I looked at the factory build sheet and it just says OM642.
It has a 9.5 litre oil capacity unlike the one on your PDF that states 8.5 litres.
Interesting too that the Jeep 722.6 uses ATF+4 and not the Merc' spec.
Thanks for everyone helping.
I cut and paste this from a Jeep forum. The guy 'merlin' is a Jeep mastertech so does at least give some credence to his words. Older post but still relevant.
Opinions please?
https://www.jeepforum.com/forum/f67/...-grand-493293/
Thanks.
Last edited by Jeep driver; Apr 26, 2020 at 08:09 AM.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
What post on Jeep forum says about lubricating bearings?
There is long way from Master Technician, aka a guy who can operate wrenches to top-end engineer designing MB engines.
There is long way from Master Technician, aka a guy who can operate wrenches to top-end engineer designing MB engines.
MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
Likes: 153
From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
Yup, "top end". I'm guessing the same top end engineers who designed the EGR system, as well as the DEF set up. You know, the ones that takes a dump before the vehicle has 25k miles on the odo.
Maybe the same genius who designed our blind spot system, which took a dump on our truck at 40k miles? Not to mention the bean counters, who ultimately decide what the "top end" engineers get to implement in the actual build of the vehicle.
Yeah Krzy, top end!!!
Maybe the same genius who designed our blind spot system, which took a dump on our truck at 40k miles? Not to mention the bean counters, who ultimately decide what the "top end" engineers get to implement in the actual build of the vehicle.
Yeah Krzy, top end!!!
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
There is also big difference between engine mechanical design and adding emission gadgets to it.
Think about it?
Soon any tire changer with 2 hr of job training will spam the net about Bluetecs. They are professionals working in the field afterall.
Think about it?
Soon any tire changer with 2 hr of job training will spam the net about Bluetecs. They are professionals working in the field afterall.
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
Fair enough, in this post he says 'to prevent crankshaft damage'.
Master tech is the leading mechanic in a dealership so in my opinion is worth listening to. Also he does say he got this procedure direct from Jeep so does that carry any weight? I concede it is curious why Jeep/Chrysler advised this and not Mercedes.
Many thanks everyone.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
Would you find the mentioned Jeep note on the issue, that might be interesting. Otherwise I don't pay much attention to trolls.
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
Hi
A little harsh to accuse an apprentice trained, jeep main dealer master tech as having 'no education and experience'. In UK 90% of the Jeeps and Chryslers he will have seen will have been OM642. As for being a troll, well your idea of one is different to mine.
No, unfortunately he did not post any documentary evidence. Hence I came here to ask on a Mercedes forum.
Thanks.
A little harsh to accuse an apprentice trained, jeep main dealer master tech as having 'no education and experience'. In UK 90% of the Jeeps and Chryslers he will have seen will have been OM642. As for being a troll, well your idea of one is different to mine.
No, unfortunately he did not post any documentary evidence. Hence I came here to ask on a Mercedes forum.
Thanks.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
That is how I can tell educated and knowledgeable person from troll.
I think you misunderstood my previous comment. Master technician is master in technical repairs.
What does he know about designing oil systems on top of the line engines?
This is not his job description - plain and simple.
I think you misunderstood my previous comment. Master technician is master in technical repairs.
What does he know about designing oil systems on top of the line engines?
This is not his job description - plain and simple.
Senior Member
Joined: Apr 2012
Posts: 356
Likes: 66
2012 ML350 Bluetec, 2015 GL350 Bluetec
This is a common practice developed by auto mechanics, but not called for by any manufacturer service manual. The main purpose is to shorten the time of the oil pressure buildup, during which the engine is basically running without oil. Most of our auto engines have wet-sump oil system that oil runs from oil pan to pickup tube--oil pump--oil filter then to every part that needs lubrication. Usually there's a one-way valve between the pump and the oil filter to ensure that the oil filter housing is filled after the engine shuts down. After an oil change, if the oil filter housing is not filled, then the oil pump will need a few seconds to fill the oil filter housing before the oil can be delivered to all the surfaces. This is why you can see the oil pressure warning light keeps on for a few seconds on the first start after the oil change. Pre-filling the oil filter housing can substantially shorten this time.
The fact is that, the difference is very small and the gain is probably neglegible. A few seconds without oil will not cause any damage to the engine at all. Most of time we change oil when the engine is warmed up so there should be some oil on most parts that will last at least a few seconds as well. But it doesn't hurt to do it as you are just changing a location to pour oil in and usually it's much easier to pour oil into the oil filter housing rather than the filler port.
Long story short, mechanics thinks it's a good practice INTUITIVELY and it's convenient for them to do so as well, but engineers who designed the engines don't think it make any difference.
The fact is that, the difference is very small and the gain is probably neglegible. A few seconds without oil will not cause any damage to the engine at all. Most of time we change oil when the engine is warmed up so there should be some oil on most parts that will last at least a few seconds as well. But it doesn't hurt to do it as you are just changing a location to pour oil in and usually it's much easier to pour oil into the oil filter housing rather than the filler port.
Long story short, mechanics thinks it's a good practice INTUITIVELY and it's convenient for them to do so as well, but engineers who designed the engines don't think it make any difference.
Last edited by geniushanbiao; Apr 30, 2020 at 11:41 PM.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
If you are old enough, some of those "Masters" design electric oil pumps like 30 years ago.
The purpose was to start oil pressure when you open the door, or turn the ignition to on and have the engine cranking with full oil pressure.
Even that was dino oils era, the design never catch up as it did not make noticeable difference.
Than synthetic flood the market and they have high % of molybdenum in it. Molybdenum penetrate the bearings surface for semi-permanent slippery coating.
You should be able to find old movies showing engines who drained synthetic oils - making a mile run with no plug in oil pan.
Bottom line, even if you'd have a proof that it does make a change between engine dying at 300k miles v.s 320k miles. Would you care?
The purpose was to start oil pressure when you open the door, or turn the ignition to on and have the engine cranking with full oil pressure.
Even that was dino oils era, the design never catch up as it did not make noticeable difference.
Than synthetic flood the market and they have high % of molybdenum in it. Molybdenum penetrate the bearings surface for semi-permanent slippery coating.
You should be able to find old movies showing engines who drained synthetic oils - making a mile run with no plug in oil pan.
Bottom line, even if you'd have a proof that it does make a change between engine dying at 300k miles v.s 320k miles. Would you care?
MBWorld Fanatic!
Joined: Sep 2005
Posts: 6,189
Likes: 242
From: Albuquerque
'10 CL550, '12 GL550
The thing is, engines do NOT “run without oil” at first start after an oil change. Everything remains coated with oil, and this coating provides sufficient protection and lubrication during the (extremely short) pressure build up interval.
Even mechanics can conjure up theories ... they are never engineers that have designed, developed, and tested an engine.
Perhaps there are occasions where someone drains oil and then does not refill and start the engine for a week, but ... who cares?
Just learn to ignore mythology. This is 100% what the “Jeep” thing is. I for one do understand ...
Even mechanics can conjure up theories ... they are never engineers that have designed, developed, and tested an engine.
Perhaps there are occasions where someone drains oil and then does not refill and start the engine for a week, but ... who cares?
Just learn to ignore mythology. This is 100% what the “Jeep” thing is. I for one do understand ...
Senior Member
Joined: Apr 2012
Posts: 356
Likes: 66
2012 ML350 Bluetec, 2015 GL350 Bluetec
The thing is, engines do NOT “run without oil” at first start after an oil change. Everything remains coated with oil, and this coating provides sufficient protection and lubrication during the (extremely short) pressure build up interval.
Even mechanics can conjure up theories ... they are never engineers that have designed, developed, and tested an engine.
Perhaps there are occasions where someone drains oil and then does not refill and start the engine for a week, but ... who cares?
Just learn to ignore mythology. This is 100% what the “Jeep” thing is. I for one do understand ...
Even mechanics can conjure up theories ... they are never engineers that have designed, developed, and tested an engine.
Perhaps there are occasions where someone drains oil and then does not refill and start the engine for a week, but ... who cares?
Just learn to ignore mythology. This is 100% what the “Jeep” thing is. I for one do understand ...
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
Oil will not deplete from bushings in couple of seconds.
Growing up in Poland, in my young years I was riding steam trains quite a lot. Lot of bushing in wheels drive did not have constant lubrication. At each stop the machinist would take an oilier and put few drops of oil on each bushing.
That was good till the next stop.
I bet lot of MB owners had no idea what was the purpose of the tool
Growing up in Poland, in my young years I was riding steam trains quite a lot. Lot of bushing in wheels drive did not have constant lubrication. At each stop the machinist would take an oilier and put few drops of oil on each bushing.
That was good till the next stop.
I bet lot of MB owners had no idea what was the purpose of the tool
Senior Member
Joined: Apr 2012
Posts: 356
Likes: 66
2012 ML350 Bluetec, 2015 GL350 Bluetec
Oil will not deplete from bushings in couple of seconds.
Growing up in Poland, in my young years I was riding steam trains quite a lot. Lot of bushing in wheels drive did not have constant lubrication. At each stop the machinist would take an oilier and put few drops of oil on each bushing.
That was good till the next stop.
I bet lot of MB owners had no idea what was the purpose of the tool
Growing up in Poland, in my young years I was riding steam trains quite a lot. Lot of bushing in wheels drive did not have constant lubrication. At each stop the machinist would take an oilier and put few drops of oil on each bushing.
That was good till the next stop.
I bet lot of MB owners had no idea what was the purpose of the tool
I believe the oil light on the dashboard was inspired by this lol!
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
Hi Lads
Thank you all for replying.
I did find a Jeep technical service bulletin about the OM642 and crankshaft bearing issues. If you read it says the problem can occur after an oil change.
Was this TSB sent out to Mercedes garages?
http://www.wkjeeps.com/TSB/tsb_wk_0900108.pdf
Thanks.
Thank you all for replying.
I did find a Jeep technical service bulletin about the OM642 and crankshaft bearing issues. If you read it says the problem can occur after an oil change.
Was this TSB sent out to Mercedes garages?
http://www.wkjeeps.com/TSB/tsb_wk_0900108.pdf
Thanks.
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 38
Likes: 5
From: uk
Jeep 3.0crd
i again had a look at the oil change instruction if i have missed anything. It does not state anything like pouring some oil into filter housing. My engine code with extension OM462.950. Maybe that makes any difference? Do you know what numbers are after the 642 on your car?
I am attaching the instruction to which i am referring.
I am attaching the instruction to which i am referring.
The Jeep uses the OM642.980.
Thank you.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
Hi Lads
Thank you all for replying.
I did find a Jeep technical service bulletin about the OM642 and crankshaft bearing issues. If you read it says the problem can occur after an oil change.
Was this TSB sent out to Mercedes garages?
http://www.wkjeeps.com/TSB/tsb_wk_0900108.pdf
Thanks.
Thank you all for replying.
I did find a Jeep technical service bulletin about the OM642 and crankshaft bearing issues. If you read it says the problem can occur after an oil change.
Was this TSB sent out to Mercedes garages?
http://www.wkjeeps.com/TSB/tsb_wk_0900108.pdf
Thanks.
I am pretty sure I don't know all the versions, but I do know that OM642 has dozens of models. Not only filters and piping come different on different vehicles, but I know the engine is tuned from 168 HP in Sprinter vans to 250 HP in newer sedans. That's pretty wide spread in tuning.
So I just wonder if for Jeep application they modify the engine (again) and side effect is weak bearing? What's HP rating in Jeep?
