I have an 82 300SD. I've gathered from reading that for a diesel, you want to do oil changes with oil that is made for a diesel? Is that true? What should I look for? How do I tell what is good for diesels? Then I get my oil changed, should I ask for it specifically?

There will be all kinds of ratings on the back starting with CH or I. search on here will provide more information than youll ever want to know. You may want to thinka bout swtching to 5w40 mobil 1 (delvac 1 or diesel turbo truck same stuff different labels). im moving over to it from dino, I have heard that it can even fix oil smoking problems. well see.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

After purchasing my '82 300D four years ago, I immediately changed out the 15W-40 oil and started using Mobil's synthetic 5W-40 Delvac 1 (it was also recently packaged in quarts as Mobil1 5W-40 for Truck and SUV) and ~70k miles later I am still waiting for the motor to turn into a leaking sponge or succombing to premature wear. I have it changed every ~5K miles.

__________________
'82 300D Turbo 204K
'10 Toyota Prius 85K
'13 AMG C63 (P30) 23K
'14 Audi Q5 TDI 46K
'16 RAM 2500 CTD 12K

'10 VW Jetta TDI 65K (traded)
'12 Nissan Leaf 34K (returned end of lease)
'15 Audi A6 TDI 25K (traded)
'95 E320 166K (traded)
'93 300D 2.5 Turbo 168K (sold)

The bigger issue is that you ask if you should ask for Diesel rated oil when you bring your car for an oil change. That means you're taking it someone who might not know these engines. I'm half cringing hoping you say that someone other than Jiffy Lube or some 5 minute shop changes your oil.

Lots of independents use oil not specifically rated for Diesels with no ill effect. Still, since there's no appreciable price difference between, for example, Castrol GTX 20W-50 and Chevron Delo 400, why not go with Diesel rated oil?

Rather than get into oil types and change intervals, I'll suggest that you learn to do oil changes yourself. It's not difficult and it's a great first step in getting to know your car. You can read the gravity drain vs vacuum extraction debates in the archives There are also debates on filter brands, ramps vs jackstands vs not lifting the car, etc. If there's a choice, you can bet there's a debate.

Sixto
93 300SD 3.0

I disagree! we all know that if you use aa extractor, you dont need to use ramps OR jackstands.

- well, ok, dmtinkerer, but you should read up on oil- you could spend days doing it.

__________________
1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

I've rebuild engines and transmissions and am a fairly good shade tree mechanic but its always been gas engines. I know how to do an oil change but having done them for 30 years I'm getting to a point in my life where I can have someone else do it.

No, I don't take it to Jiffy Lube. I have a "german import" specialist that does Saab, Mercedes, BMW etc...but I don't know how much diesel work they do. I talked with the owner who seemed fairly knowledgeable. I just wanted to know so I know what questions to ask or I wind up having to do it myself. I also want to know what's going on in the engine. Not knowing diesels, I don't know how much oil choices matter. It may matter much more than gas engines. I know with Saabs (I've owned 6 of them) that it does matter which plugs you use and what type of oil you use for the gear box. For my old Fairlane...not so much.

I did try doing a search but got swamped with info. My questions were simple. I'm not yet at a point where I'm considering the molecular structure of the oil. I just wanted to know general rules to follow until I get more into it.

google is your friend :

"site:mercedesshop.com search words here"

Also use advanced search and only search the titles. Everyone here can agree that the search engine sucks in vbulletin.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

I did do several searches, but, as I noted, I got overwhelmed with info. I just wanted to know if I should buy diesel oil or can I get away with regular motor oil.

Ok, I'll give it a go. Regular non-diesel motor oil will work fine if you change the oil at 5kmiles, which Mercedes recommends as the interval.

Diesel grade dino oil (non-synthetic) will easily go 10kmiles between changes as it can handle the extra soot these old diesels put in the oil.

Diesel grade synthetic oil will go much longer, depending upon the condition of the fuel you use, your driving patterns etc. Some certifiable nutbags go 20 to 30kmiles on one pour of Mobil delvac.

240Joe

Use diesel (C-rated) oil and change per your manufacturer's recommendations.

Do not exceed the drain intervals recommended by Mercedes unless you verify oil condition through oil analysis, performed by a certified laboratory.



Tim

__________________
2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

dmtinker,

Some caution is called for when asking for opinions :-)

Clearly, synthetics are better than dino for almost everything - perhaps everything.

In my opinion, some of what 240Joe says is accurate - some isn't - and, even though I agree with that portion said, much of what he says is too broadly and flatly stated - leading one to think it might be fact.

I have had several diesels - the one thing I enjoyed and hated doing, were the oil changes. Synthetics were clearly better 20 plus years ago, so I was an early adopter. One does need to change oil more often in a diesel than a gas engine - as everyone has noted, it is a particulate issue - the key is finding a balance that works for you and your equipment. Avoid the high rate chang (2-3K) as this has been shown to be more frequent than needed - and, avoid the long interval change ((10-15K) as this has been generally shown (I know special filter systems can prolong the life, but they are expensive to buy and to install to solve a simple problem) to be too long - on average. The onboard service notification systems on MB and Toyotas (the later having been involved in major sludging lawsuits) generally don't go much beyond 10-12K or so - this should be telling us something basic - they are being a bit cautious - and, this is with very modern gas engines.

Older diesels tend to put out more particulates than newer ones, so later model MBs and VWs can probably go a little father than older engines - particulates only. Other issues about the same.

So, I am a 6K kinda guy with synthetics -and, I strongly prefer using a Topsider to draining - even though I have a lift. It is simply cleaner - and, I don't have to remove the under engine cover. Every few changes I do pull the cover and drain, but this is more to assess what is happening with other leaks, etc than to accomplish the oil change.

I would never go longer than 10K on any engine or any kind, UNLESS, I was getting the oil analyzed every 2K after about 6K.

I don't smoke crack, either.

I love oil threads.

__________________
George Stephenson
1991 350 SDL (200K and she ain't bent, yet)
former 2002 E320 4Matic Wagon - good car
former 1985 300 CD - great car
former 1981 300 TD - good car
former 1972 280 SEL - not so good car
a couple of those diesel Rabbits ...40-45 mpg

Changing diesel synthetic at 6kmiles is like wearing suspenders, a belt, a jock strap, and castrating yourself just in case. WOW!. Why use synthetics at all with that OCI.

Don't worry folks, I DO know what I'm talking about, and I practice what I preach.

Can someone please post a case of a verifiable engine failure caused by extending the OCI? Please? Oh come one, just one......

240Joe

I believe the question was pretty basic - is there a specially formulated oil for Diesel engines, should dmtinker use it exclusively, and how can he tell he has purchased the right stuff?


First the answer is yes. Diesel engines spew much more combustion by products past the rings and into the oil sump than any gas engines. The soot content is so severe it will turn the new oil black in a few minutes. Other combustion by products, including moisture and nasty, unfriendly gasses that will turn gas engine oils acidic, cause them to lose their ability to control viscosity changes with temperature. Diesel specific oils have different additives to address these more severe conditions. When you look at the bottle of oil, you will see a string of SAE certification annotations. All the ones that start with the letter "S" apply to spark ignition engines and all the ones that start with the letter "C" apply to compression ignition engines (Diesel engines are compression ignition, so you want these). The designators have two letters, the "S" or "C" followed by another letter. The second letter denotes a chronological sequence, with "A" being the first and "B" the next and so on. Today the Diesel oil designator is CH or CI, which is more than adequate for a 240D.

Synthetic is not specifically one of these SAE categories. Synthetic is usually a label designation, and there are rules for this, but each manufacturer makes his own interpretations. MB tests oils and certifies them for use in their engines. For newer cars only some synthetics and no Dino oils make the grade. For the 240D that is not the case.

I live in the Northeast and it gets cold enough that the starting benefits of synthetics are worth it for me. I use Mobil Delvac 1, a 5W-40, very high quality synthetic base oil with a very well engineered additive package. I use it on all my cars (gas and Diesel), and if you work on your engine at all you will notice one benefit is the oil doesn't permanently stain your skin black like other oils. I run it for about 8,000 miles between oil changes, unless I have an oil user, in which case I top off as needed and extend the change up to 12,000 miles.

If you are interested in doing the oil changes yourself, I recommend the sucking out the dipstick tube method for ease and simplicity. Oil changes are the most regular maintenance steps for these cars, and the suck it out the dipstick tube method makes the threshold for getting out there and doing the job so low, there is no excuse for not keeping up with the changes. Good luck and I hope this helps. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I've used Rotella in all 7 of our diesels for the past 26 years - I'm also a 'drain it as God & the German engineers designed it' kinda guy - out the drainplug from the bottom -

Good time to assess other aspects of the car from below...

bnc

I'll give it another go.

Definitely use diesel rated oil, there is no reason to use the incorrect oil for any change interval.

Most folks change oil at about 3-5K with dino oil or about 5-10K with synthetic, I prefer the low end of these ranges. The recommended interval for your car is 5K miles, I wouldn't recommend a significantly longer interval without an oil analysis. In my case, a 10K interval resulted in high levels of soot, so I currently use a 5K interval with a 5W40 diesel rated synthetic (either M1 or Rottella). I don't know of anyone credible who would recommend a 20 or 30K interval.