Hey Guys,
I own a 2007 R320 CDI without a DPF fitted. I am due to do an oil change on it and want to clarify some things. MB 229.51 is the main approval for the OM642, especially for mercs fitted with a DPF(requiring a lower ash oil). Apparently low ash oil compensates slightly for engine protection to help with the DPF. Is this true?
If this is true, would I be better off using 229.5 (does not have low ash additives) which is approved for OM642's without a DPF?
Thanks,
Tom

 

Why use lower quality oil, when for couple more bucks you can have the best?
Especially when you read topic about OM642 seizing on inadequate oils?

 

Are 229.5 oils lower quality?
I do want to use the best quality oils, whats your recommendation?
Thanks

 

I think the OP's point was that the earlier spec oils might be better lubricants but not compatible with the DPF, which he doesn't have.
I think the lower spec Diesel oil may be 229.31, not 229.5

 

No DPF, Delvac or Rotella.

 

Actually with DPF it doesnt make sense to not use any low ash oil. I used the rotella and conventional delo 15/40 with my dpf on my cummins. No issues. Then I got rid of that stuff and kept using the 15/40 and now have 165k miles on it no issues.

Everyone specs there own oils for there engines but dont let that confuse ya with low ash oils. Most all current diesel oils are low ash because all the diesels have DPFs and SCRs.

The OM642s apparently have some issue where the engine sludges out and siezes. Newb MB person here but still dont understand how that happens, bad oil/no oil changes/bad engine......

 

The WRONG oil has been known to sludge in some cars due to the fact that B20 (20% biodiesel) - which is what comes out of the pumps in over 20 states in the continental US - has a higher lubricity than regular dinosaur juice diesel and gets past the piston rings (especially during a DPF regen cycle), thereby diluting the oil in the sump past the point where it can provide adequate protection. Again, this only happens on cars in US states where (a) the diesel contains more than 5% biofuel, (b) the oil used does not have MB 229.52 approval and/or is left in the car for far too long, and in most instances (c) where the cars have DPF filters and perform regen cycles to burn off the soot accumulation in the DPF.

The earlier oil specs are not incompatible with DPF filters - they are incompatible with the crap that now comes out of US fuel pumps, i.e. high biodiesel percentages.

If you live in a state that has local biofuel mandates, I'd still use a MB 229.52 approved oil because you can't avoid the biodiesel no matter what, and some of it is still going to slip past the piston rings even if you're not squirting in unburnt fuel during the exhaust cycle. If you live in Canada or a state where you know that there is no more 5% biodiesel content (B5), then you can use a considerably inferior oil spec like 229.31 - if you change the oil at least twice as often as it is considerably inferior to even the 229.51 spec when it comes to drain intervals.

Very few if any OM642 engine have failed as a result of mechanical wear. The vast majority of the ones that have failed have done so because the oil was no longer able to properly lubricate the motor as a result of being left in for too long (during which time it very likely suffered from significant fuel dilution). Why would you knowingly put a considerably worse oil formulation in a car to solve an imaginary problem that does not exist at the expense of creating or accelerating a real problem that does exist?

If shear protection is what you're after, Shell Rotella T6 is an excellent oil (I run that in a number of gasoline powered cars with flat tappet lifters), but when the enemy is the oil's inability to deal with "normal" drain intervals as opposed to mechanical shear, stick with oils that have been specifically designed to neutralize the enemy you're fighting instead of trying to neutralize something that doesn't actually exist while you are leaving your engine completely unprotected against the very thing that has been known to kill them.

Gotta love the armchair oil experts.

 

Especially those, who never use labs for oil testing

 

Thanks everyone for the constructive info shared, I appreciate it. It definitely seems worthwhile to get my oil tested at a lab.
I looked up the Shell Rotella T6 and couldn't find any for sale here (I live in Australia).
I have come across Liqui Moly Top TEC 4110 5W-40, that has the 229.51 approval as well as 229.31 and 229.52. Would this be a good oil?
If not any other suggestions?
Thanks

 

Any oil that has MB 229.52 approval is a good oil by definition - or it would not have passed the tests required to receive said MB 229.52 approval.

MB 229.52 is a relatively new diesel oil spec that has better ability to specifically deal with oil dilution (by biodiesel) and is a slightly lower friction / better fuel economy oil than MB 229.51. MB 229.31 is the old diesel oil spec that has been superseded by 229.51 as 229.51 oils are considerably better when it comes to longer drain / oil change intervals. Any oil meeting the MB 229.52 spec will likely also meet MB 229.51, and any oil meeting MB 229.51 will exceed MB 229.31 (they would be equally good at protecting your engine when they're fresh, but the 229.51 is able to protect it for a longer period of time than the 229.31 before you need to change it). The 229.51 spec is *NOT* an upgrade over the 229.5 spec - 229.5 is oil for gasoline engines only.

Shell Rotella is a HDEO oil that has neither of those standards - it is an oil designed for use in industrial diesel applications, and while it is made of very good base stocks and is thus excellent when it comes to resistance to mechanical shear, oil shear is NOT the issue with OM642 engines (but is on gasoline race engines for example where high RPMs are the enemy and where you dump the oil after every race weekend and you never need to worry about dilution). As I said, get the oil that provides the best protection in your engine (any MB 229.52 oil), not an oil that provides the best protection in a heavy-duty Caterpillar diesel excavator or a race car motor that is in operation for 24 hours a day three days a week and 21 hours on the fourth day with a three-hour downtime for maintenance including an oil change. It is not what the oil was designed to do. Get an MB 229.52 approved oil.

In Australia you have a generally warm to hot climate, so a 5W-40 would be a good choice (although most of the 229.52 oils are 5W-30). You can check which specific oils have the required approval for your car at https://operatingfluids.mercedes-ben...heet/229.52/en - if the specific oil is listed there, you can use it and sleep well at night (yes, the LIQUI MOLY Top Tec 4110 is approved).

 

229.52 oils don't go above 30 weight grade as they are design to save up to 7% of fuel consumption.
Old school mechanic advise heavier oils for warm weather, but how many old mechanics do have degree in chemistry?
The fact is that modern oil modifiers improve the oils more than heavy weight does.
Bottom line, I often use my vehicle in temperatures above 120F/40C on 30 weight oils just fine.

 

Dont understand this one, if it can handle a cat diesel and a gas race engine (both extremes of either spectrum) how can it not handle the om642? All the other diesels in the US run the same diesel from same pumps and dont sludge up. I run a c4 oil conventional in my cummins for upwards of 15k miles intervals and dont have any sludging. Ran the rotella before also but dont anymore. Armchair or not i dont see how it makes any difference. There is some other issue. Maybe the biodiesel combined with a smaller sump and long change intervals? Maybe could detect rising oil levels if it wasnt leaking out all the time, not sure.

Begs to wonder what the actual difference between .51 and .52 actually is? I do know my om651 has apparently ran the .51 5w40 for about 80k miles and now that i have it will run either and eventually who knows will see. I know mb calls for 15w40 in my climate range so...

 

I too don’t buy into the .52 and anti-sludge. As I have said earlier (maybe on this string) I have run T6 in my OM642 since I got it with 96k miles on the clock. It now has around 178k miles on it and all that has been done is the AEM, cooler seals, addition of a ProVent 200 and 5k OCI’s, engine wise. I also service all fluids at 1/2 of the manufacturers recommended intervals. Some say it’s stupid and wasteful however I tend to get really high miles on 99% of my cars. The one exception is my wife’s 2014 GL450 (M278) that galled the cylinders before it hit 100k miles. Her car is the only thing I didn’t use T6 in……….. Now she has a Lexus LS460 and if T6 was available in a 5W-30 I’d be running it in that car too.

The only other wear item I have had an issue with was the transfer case chain and that wasn’t the chains fault. The dealership this thing was serviced at obviously never checked/changed that fluid. When I pulled the plug on the chase I got maybe a 1/2 thimble of nasty fluid. In my book the vehicle is good and the engine is good.

 

This is blunt statement, who is avoiding details.
OM 642 engines have been manufactured for about 20 years and they have tens of variations.
From 168 HP to 250 HP, no emission, DPF only, DPF + SCR systems.
Even they have the same block model number, they are totally different animals. If you READ bevmo, you will find that only at certain MY they require 229.52 category oils (2014 from top of my head, but please do your own homework).

 

While the vast majority of the 270+ MB 229.52 approved oils are indeed 5W-30, there are a dozen or so oils on the BeVo list that are 5W-40, including the one the OP asked about (see https://operatingfluids.mercedes-ben...heet/229.52/en). I completely agree about the viscosity modifiers and that anything higher than 5W-30 is completely unnecessary.

The oil in those two situations indeed needs to deal with extreme mechanical shear, but it has to do almost nothing when it comes to dealing with moisture, neutralizing acidity, preventing deposits from forming on internal engine components, removing and suspending dirt and contaminants in the oil, providing adequate protection across a wide range of temperatures, providing protection to the emissions system and helping with engine fuel efficiency. I'm sure you've heard the expression "Jack of all trades, master of none" - and it most certainly applies to engine oils. A racing oil has to do one thing only so it does not need various additives like detergents, friction modifiers, antioxidants, corrosion inhibitors and viscosity index improvers that are all essential in oils for street driven cars and in this case are the things that prevent the oil from turning into a sludge. And yes, you are 100% correct about the "biodiesel combined with a smaller sump and long change intervals" - that is exactly the problem. The 229.52 spec oils contain additives that the 229.51 spec oils do not (or do in much smaller concentrations) in order to minimize the effect of the biodiesel and resulting oil dilution.

Whether you buy into it is up to you, just like whether you believe that COVID vaccines are beneficial is also up to you regardless of what the science says. That's your prerogative. Sure, if you change the oil often enough it will never sludge up, but the question then becomes "how often is often enough" - which greatly varies for any given combination of a specific oil, specific engine and type / style of driving. Most car owners in America only do the absolute minimum in terms of maintenance and never do a UOA to find out how much life is left in the oil, so when you combine that with the high biodesel content, inadequate oil additives to deal with the same and everything else that shortens the oil's life in a passenger car (like driving mostly short trips when the engine never fully warms up and stays hot for example), you have a recipe for disaster. And, last but certainly not least, there are many flavours of the OM642... they come in various states of tune and emission control systems, so what may be good for the early ones may be very different from what is required in the later ones.

 

I have the service records for this car which was 100% dealership maintained until I got it. Using whatever the dealership used for oil didn’t work out the best for the previous owner. I say that due to a timing chain replacement, after warranty, at 72k miles. I have since put over 100k on it and asked my mechanic to check chain wear. He is going to do it after the first of the year but asked if I were hearing chain rattle at startup, noticed decreased fuel mileage or a difference in performance, all answers are “not in the least”.

Your encouragement prompted me to dig back into the 540rat blog to refresh my memory on oils and I appreciate that. There are oils that appear to have much higher wear protection than T6 however it is really hard to dig up good solid information on if those oils handle soot well. I agree with many folks that all vehicles offered in the US are being affected by CAFE rulings and pressure to reduce the fleet fuel consumption which, in my mind, causes oil companies to have to develop oils that bend towards rulings instead of what’s best for engine longevity. I do not care about 1 to 1.5 mpg I do care about 3-400k miles since I run a territory spanning 4 states.

What specific oil would you use if the DPF was not an issue knowing the oil will be changed at 5k and that this vehicles shortest trip is 60 miles one way on the interstate at 75 mph? Serious question! I settled on T6 because it’s a diesel oil that, by reputation, handles soot well and in my mind soot is an abrasive that I want handled as best possible (main reason for 5k OCI).

 

Your link shows only some exotic oils , not available in USA.

 

The timing chain stretching has absolutely nothing to do with the oil - the double-row timing chain on some of the earlier models was known to stretch over time. At 72K miles (~116K km), it may be a little worse than average, but I would not consider that anything out of the ordinary. Nothing lasts forever. They likely replaced it with the single-row chain that is more durable, but again, having to replace a timing chain or belt is not unrealistic - it's a wear-and-tear item. Whatever oil the dealership was using had nothing to do with it, and they were almost certainly using the MB-branded 229.51 and subsequently 229.52 approved oil they keep in their tanks "on tap".

The fact that (a) you mostly drive longer trips at sustained speeds where the moisture in the crankcase has a chance to evaporate, and (b) that you change the oil at 5K miles is precisely why you're not having any issues with it as you're not dumping all this water and fuel in your sump that stays there until the oil can no longer do its job. The worst fresh oil is better than the best old one, so for as long as your driving style and OCI don't change, you're giving the engine the best environment for it to work properly. The T6 won't damage anything internally in the motor - it has a little more ash than what DPFs can safely handle and you could possibly clog up and destroy the DPF, but if that is a risk you're willing to take, then the T6 will be fine for as long as you keep driving the way you do. Otherwise I'd switch to any approved MB 229.52 oil (which will cost you three times as much per litre - the T6 is cheap) and call it a day. As I said, in your case it's your driving style and OCI that are keeping the engine healthy, not your specific choice of oil.

 

I could have be messing up my facts but sure that the T6 is a low ash oil. It has the C4 approval rating required for the DPF/SCR equipped cummins diesel and pretty sure the Ford and GMC versions as well. Doesnt seem to clog up those DPFs. Feeling lazy or I would look up the specs between the .52 and T6 oils to see what the ash rating is. Its usually posted by the oil manufacturer on the spec sheets. Heck even the conventional 15/40 delo400 I run in my truck has a similar or same ash rating but it doesnt have to worry about the DPF anymore.

 

I was using T6 in my older Powerstrokes as well as 1998 MB diesel. Actually I used dino Rotella as well and lab tests for those engines were excellent.
Still bear in mind that newer OM642 engines develop strange chemical reactions, who turns older classification oils into gelatin.
Nobody that I could find would offer any good explanation for the phenomena, so until someone would, I would not take my chances with non-approved oils

 

Low-SAPS HDEO oils allow SAPS content =< 1%, which is what the Rotella T6 meets (MB 229.31 approval). It has to provide sufficient protection for non-ULSD diesel that is available in other countries, and while it is compatible with DPF system, it is not compatible with SCR systems using AdBlue.

Low-SAPS MB 229.51 oils are approved for use in countries with ULSD diesel fuels only, and are compatible with both DPF and SCR exhaust after-treatment systems. IIRC the SAPS contents has to be =<0.8% if not even lower as it also meets Euro 6 standards.

MB 229.52 oils provide some additional fuel efficiency over MB 229.51 oils, and critically for those of you in USA, better oxidation stability for biofuel compatibility (which is what turns the oil into gelatin) over MB 229.51 and all other previous oil approval standards.

 

This is a great point especially for diesels -- and one we do not hear often enough. Think of all those little Euro diesels that are used as grocery getters and never get to warm up. How their insides must suffer.

 

This is the 1st good explanation about the phenomena I see on the forum.
Do you have more info about it?
As for small, European diesels running cold on short run, most of them do have 3 or 4 cylinder engines. They take 1 km drive to come to operating temperature

 

Mostly from articles on sites like Lubrizol360 as well as discussions on BITOG and Sprinter Source. The MB 229.52 spec itself keeps evolving, but the only significant improvement over the 229.51 spec oil is the better oxidation stability for biofuel compatibility. MB 229.51 was fine with up to B5, but with the higher biodiesel content currently in use the oil has to have even better oxidation stability and anti-sludging properties to meet longer OCIs.

 

B5 is the highest allowable in US to sell as D2 fuel, yet a number of OM642 seized due to oil gelling, on what seems to be 229.51 oils.
How oxidation turns the oil solid would be intriguing to hear.
Any link to Lubrizol article? Sorry for nagging you, but this is phenomena, who created engines lost, so not something you want to take lightly.