Synthetic Oil Lesson
 

I'm a very hard-headed type. I inquired about synthetics, read all the posts and asked my mechanic.

He warned me that he had tried synthetic twice on older SD's and both started using oil. They resolved this pesky habit when he switched back to regular oil.

Undaunted by professional advice, I bought the 5W40 Wal Mart Rotella and gave her a shot. Seemed quieter on start up, even though I'm in Florida, I liked the idea. My 83 300SD with 160K seemed to run about the same and maybe leaked a tiny bit more.

After a few trips, I thought the old girl was smoking a bit more at night under acceleration. I noticed a puff of smoke on early morning start up's. Sure enough, the oil level dropped a little, and I noticed oil residue from the oil fill cap very slightly and blow by on the vent to the air cleaner.

I switched back to Delo 15W40 and after a 100 mile trip today where I pushed 80 mph on cruise most of the way...no oil from the oil cap or any evidence of blow by.

I learn the hard way, but don't forget these lessons.

Just thought I'd share my experience with any of you who might be thinking along the lines I did.

It is always a risk on older engines that the synthetic will leak more than dino, since it tends to lower viscosity cold.

What that really says to me is that you need new valve guide seals! Minimal oil usage with dino oil, but more with the thinner synthetic.

If you decide to try again, use 15W-50 rather than 5W-40 -- 5W oil is too thin for an old MB diesel except where it is VERY cold.

Peter

Depends on the vehicle. Dino to synthetic in the Jetta and the 300D, no issues. RT

MB recommends Mobil 1 0-40w as the synthetic oil to be used in all MB motors. You will burn oil, about one quart 800-1000 miles, for about the first 5,000 miles or so. Then you should see less and less oil consumption. Oil change is about every 20,000 to 25,000 miles, instead of 3,000 miles.
Your best interest is to switch to Mobil 1 and save money, as the dealer or garage will lose money. The mechanic best interest is to change the oil, the old way, every 3,000 miles and take your money with a smile. Go back to Mobil 1. Synthetic are the future and there are plenty of people who rather you stay with dino oil.

Bill

Shark,

I don't think you gave the Synthetic a fair chance. You have to use it for 10, 20, 30 thousand miles to see the results.

I use Castrol Syntec in a '79 300SD and it decreased the oil consumption by a factor of 3 I.E. from 3 quarts to 1 quart in 10,000 miles but it took 30,000 miles to do it. It also stopped a few oil leaks the engine had. I change the oil every 10,000 miles.

P E H

We are talking about a old DIESEL engines here...and they seem to enjoy a good grade of Dino oil 15W- 40. I ran heavy equipment throttle wide open... 10 hours a day... 6 days a week for over 20 years with NO oil problems. I changed the oil/filter often and knew of no one that had problems...these are older CAT engines with no direct injection... just like the 617 engines. I like synthetic oil in gas engines and when it is very cold...but DIESEL oil is made to deal with the soot in the oil. Newer cleaner burning engines and synthetic oil are the future...I agree....but we are dealing with 15 to 30 year old engines. " if it ain't broke ...don't fix it"

My 81 300 TD is a old Mercedes design. This design can allow the new synthetic oils but within a narrow band width. Other types of synthetic will not work. You must know which syn oil is good for your designed diesel. Diesel design varies from manfacture to manfactures and so will the type of oil recommended.
The soot level in a MB diesel should not be more than 3 percent. If it is, change the oil. There are plenty of companies which analyze the oil and state the soot along with many other things. A good tool.
The idea of " if it ain't broke ...don't fix it" is a old idea. You must find yourself broken down on the road many a time. Parts are designed with a useful life in mind, change it before it reaches the end of it's design life. It's called preventive maintaience ( spelling) or time changes on aircraft. Ever think about waiting for a airplane engine to break in flight- you can but not me.....

Bill

Those of you who have switched to synthetic, did you all go with Mobil 1? Also, how did you go about it? Did you just do an oil change and put synthetic instead of dino oil in, or did you do some form of a gradual process, or what?

I've already done the differential with Royal Purple synthetic; I'd like to do the tranny (that's another thread), but have always gone with dino oil for every engine I've had, due to the old fear of creating oil leaks that I didn't have before...

Warden,

I just did an oil change and filter change as soon as I got the cars, both 3000SDs. I used Mobil 1 15W50 in the car I use in the summer and Castrol Syntec 5W50 in the car I use in the winter because of the wider viscosity range.

P E H

With both cars as soon as I got them home they were changed to Delvac1. Within a week I'd change the tran's to Mobil1 ATF, Mobil1 ATF in the PS steering pump and Mobil1 Gear Lube in the differential. Because I've never driven my cars with dino oil I've never noticed any increased leaking. The SD is oil tight. The 240D use to use a quart every 1k mi., this is now down to 1qt every 2k mi.

I have changed over to Amsoil 15/50 in all my MBs and am very happy, no increase in oil consumption. In fact it seems that its gone down. I ran tugs for years and Delo 400 was the oil of choice but that does not mean that there is not something better out there now. BTW I use synthetic ATF in gear boxs and power stearing.:D

Chapp,

What type of injection did the CAT engines have? Did they have precombustion chambers like MB?

I know the older engines, with pony engines to start them, were very hard to start when cold, which would suggest precombustion chambers as they are harder to start when cold than direct injection engines.

P E H

Here's my synthetic story
 

When the weather turned REAL cold here, I stopped the Chevron Delo 400 and put in Rotella SB 10W40 synthetic blend. At 8 degrees fahrenheit the oil pressure gauge was staying pegged 30 seconds after I stopped cranking and it was cranking pretty slowly too. Unfortunately, the small oil leak I had has gotten bigger. Not enough to tear down and replace the rear main seal, but annoying. When the weather gets warmer I will change back to 15W40 and hope the leak goes away.

I have been running 5W40 Rotella Synthetic for about 1000 miles now, and I have found that I am using less oil than with 15W40 Delo 400. Before I was using about 1 quart for every 900 miles, and now with the 5W40 it's up to 1 quart for every 1000 miles. In the summer my oil consumption is alot less.

Interesting...I work (at the moment; looking for another job) for a tug/launch company, and they're using different stuff in different engines; divided pretty evenly between Delo, Royal Purple, and Mobil 1 synthetic...ironically, all the 12V-71's use Royal Purple straight 40 weight...and use quite a bit of it :rolleyes: I think the last boat I worked on was taking a gallon and a half per day per engine...

Egads, another oil thread. :eek:

1- PEH is right, you need to run synthetic for 10-20kmi to get full results. It takes a long time to fully clean the ring lands and free up the rings, etc.

2- It won't leak from good seals and gaskets. If it leaks, you had a leak before, you just didn't notice it as much. It will NOT CAUSE LEAKS. Mobil synthetics actually have seal-swelling properties than can SLOW leaks in certain circumstances.

3- Shell Rotella synthetic is NOT A TRUE SYNTHETIC. It is a hydrocracked dino oil that exibits some properties of synthetics and they market it as a "synthetic", which IMO is misleading advertising. I have been using this in my '84 because it was cheap ($13/gallon at WalMart) but when my stock is gone, I will switch back to Mobil-1 15W-50 ($18/5qt jug at WalMart).

4- Mobil, Amsoil, and RedLine are all TRUE synthetics that are excellent oils. I use Mobil because it is cheaper than the other 2 and more readily available. I prefer the Mobil Delvac-1 5W-40 diesel specific synthetic (designed for heavy-duty diesel applications), but this is hard to find.

5- Mercedes recommends the 0W-40 weight Mobil-1 because it is thinner and will increase fuel economy slightly. I recommend the 15W-50 weight (also MB approved) for older diesels. There is almost ZERO difference in cold pour point unless you live at one of the two Poles. The other three weights (xW-30) are NOT approved and PLEASE do not use them, they are too thin.

6- If you live in a cold area (i.e., you get snow) using a synthetic will make a BIG difference in cold starting ability. Try it, you'll be amazed. Synthetics are also much better for turbcharged engines, which create brutal heat loads for engine oil.

7- Some folks have noticed viscosity breakdown with Castrol Syntec 5W-50, which is also not a true synthetic. It may not be suitable for extended drain intervals.


For the record, both my 87's use oil at 3-4000 miles per quart (the one was 7500 miles per quart, but has valve guide or seal problems now). My 1984 is about 2000 miles per quart. I do oil analysis (Delvac Accutrack) on all 3 cars at every oil change. I change the two 87's every 10kmi and the '84 at 5kmi, as it gets more city use. All tests come back with MUCH less than 3% soot. My 87's are below 1% even at 10kmi.

For you folks burning a quart in 1000 miles or less, I'd try to find out why, and seriously consider using dino oil simply due to the cost of feeding an engine $5/quart every 1k. :confused:


Best regards,

Warden

Ya on the boats you talk about adding oil by the GALLONS, seems rather odd here. I started as a deckhand down there, worked for ten years and finally figured out i was going to have to wait till somebody died before I could get a skipper's job so I went to Hawaii where boatmen were harder to come by. I ducked into SF (ugly weather) a couple of years ago on my way up the coast and couldn't even find a place to tie up along the water front. All the docks were falling apart or had been turned into tourist traps. The city was beautiful and we wound up with a good berth next to the maritime museum boats for a couple of days. The Bay is a nice place, just too many people around it.:)

10-4 on that! I'm a deckhand at the moment, but I'm using the job to raise enough $$ for college (4 year school; I've already finished at the 2 year level and chose to take a year off instead of working while in school) and I hadn't been told that it was a union job until maybe a month ago (right at the deadline to join; hence they haven't asked me to work since)...and, no insult intended to the union or its fine people, but I'm not ready to take that step at this point in my life (especially because, after finishing in school, I'm planning to get into the aviation field). There's also the fact that they only pay $1/hr extra overtime that's got a lot of people sour...

Just wondering, when you were down here, what company were you working for? BTW, I've also been in the Sea Scout program for over 9 years :)

P.E.H.

You're probably right, I ran synthetic (or whatever it really is) for about 2K miles only.

When the old girl started puffing on start up and showing blow by, I wimped and went back to dino oil.

I love to add stuff to oil and fuel, must be some deep rooted emotional problem. I remember when I added $250.00 worth of Slick 50 to a pair of detroit 871 T.I.'s only to find later that it was probably trapped in the oil filter.

Give me a bottle of Red Line 500, some teflon this and teflon that and I'm a happy camper.

My performance has picked up, however, I outran a driveway slug the other day.

Warden

Ya ,go for the aviation. IMO The merchant marine industery is not very good anymore, at least the tow boat side of it. as you know it cost a fortune to keep up your rattings plus flying sounds like allot more fun. Maybe just as costly to keep up? I worked for several; "inside" compenies, SF towing, Harbor Tug & barge, Red Stack. I'm an old guy as that was in the "60"s, all of them. It was all union so the cashola and time off was OK. I shoulda been an engeneer as jobs ashore are more plentafull and I wouldnt be such a rookie with my 240Ds :)

P.E. H.

I'm not sure about the pre-combustion chambers...I went to my local CAT dealer and CAT still only uses Dino in engines...but synthetic in drives/trans. I was told they started using synthetics in engines and didn't like the results and went back to Dino for some reason. The don't fix it if it's not broke comment was referring to oil...not the rest of the car. I'm almost sold on the synthetic....but.

CAT actually markets a synthetic 5w-40 that is rebranded Mobil Delvac 1, one of the best oils on the market formulated specifically for diesel engines. I wouldn't shy away from it.

I, too, am dropping Rotella T because of Walmart's 50 percent price hike. May go Delvac, as it's just about the same price per gallon as Mobil 15w-50 (ouch!).

Gixxer, how have your analyses fared on the latter's soot retention ability, it not being a CI-4-rated diesel oil?

Oh, okay...the company I'm working for (Westar) wasn't formed 'till the early '70's, I think. Harbor Tugs is still around, although I haven't seen any SF or Red Stack boats (Red Stack may have changed their name). The biggest problem, at least with where I'm working, is that the union (MMP) is downright weak, and that coupled with the overtime pay (or lack thereof) gives the company no reason not to work people for 36 hours straight...I haven't been stuck doing that yet, but I'm sure it's just a matter of time...

The flight ratings aren't that bad to keep up, and my goal's to be a commercial airline pilot; unless things change (which they might), there will supposedly be a calling for pilots right around the time that I'm ready. Besides, it's been a lifelong ambition, eh? :)

Hi Dana,

Funny you mention the CAT synthetic, as I just bought 2 gallons from the CAT dealer. They were easy to locate (visible from freeway) and I have no clue where the Mobil distributor is (I moved here 7 months ago). It wasn't easy, as I had to convince 3 different CAT parts employees that yes, CAT does indeed sell synthetic engine oil! All 3 were dumbfounded when they discovered I was right. I eventually left with 2 gallons (at $21/gal) leaving them all shaking their heads is disbelief. Very humorous, at least to me. :D :D

About the ratings & soot. Both of my OM603's seem to have VERY low soot production. My 10k analyses come back in the 0.8-1.5% range. I'm about to change it this weekend so I'll get another analysis report in 2-3 weeks. My OM617, however, is up around 1.8% in only 5kmi. I've been feeding it the Rotella Syn that I picked up cheap. After the next change, I'll be out of Rotella and permanently stick with Mobil products. I have only used Delvac in the 603's. Either way, I'm not worried about the rating, I believe Delvac will carry something like 4% and from my 603 analysis that would occur somewhere beyond 25kmi...! :)


Regards,

gsxr,
Are you getting 10k from the oil filters also? I have been running the synthetics but I have been changing the oil at 5k intervals.
Thanks for the information.
tom

Yes, I am now. I used to change the filters at 5k, but Doc Booth on the MBZ.org diesel list finally convinced me it was a waste. The stock filter doesn't remove soot, it's the oil's job to suspend it. And there shouldn't be enough crud otherwise to plug the filter up. The newer Mercedes engines with FSS allow 10-25kmi changes (approx) with no special filtering, only requiring synthetic oil. So, I feel comfortable up to at least 10k, maybe even 15k. Maybe if I did 20k intervals I'd change at 10k? :D


Regards,

Dave

Where do you send your oil for analyses? and what is the cost?
Dr. B. is indeed a wealth of info. I have the feeling if you were in one of his classes you had better listen up :)

Warden

Sounds like a good job to keep as long as your in school or to fall back on. Any rattings you get might be worth keeping up. I would keep mine up but I'm ready to retire and just play with my old Benzs and work part time when I can. Good Luck

COST - VS- BENEFIT
 

I think that most folks would agree that synthetic oil has superior friction reducing qualities, hence less wear. HUGE PLUS!!!

That said, is it worth paying 2 to 3 times the money?

From an economic perspective:
if a person buys a new car and drives it 200,000 miles using synthetic oil he benefits and so does the next owner.

however, if a person buys a new car and gets rid of it a 100,000 miles, I think the 2nd owner gets the better deal.

From a personal perspective;
I use synthetic oil because I feel confident that it "flows" better on cold start-ups, it can tolerate higher temperatures, it sticks to metal better, since it does not break down there is no sludge. I'm sure there are more good things to say about it.

I think the extra $money$ I spend on synthetic oil just makes me FEEL better when I get around 5K on the oil I know I will change it soon but there is no rush, (barring soot factor, I have no idea how much soot is in my oil at 5k)

Not to put down conventional oils, as we know many well designed engines, have done very well with regular oil&filter changes.

sorry for rambling, but thats my .02

(75W Royal Purple in diff.)
(30W Royal Purple in 4-sp trans)
(5W-40 Rotella Synth. no usage or leaks to speak of)

dave

Steve,

I use the Delvac AccuTrack analysis "extended drain" kit, which costs $12.50 per kit. This kit also tests for TBN and FSOOT numbers, which the regular $9 kit doesn't. Add shipping to that number (say, $5 per order) and then shipping to send the sample to the lab (another $3-4 per sample). So total cost is about $20 per analysis. I order the kits fom Snider Petroleum in Sumner, WA (800-773-8357).



Dave240,

You have a good point, of course. In a car you don't care about and don't plan to keep for a long time, there isn't much reason to use synthetic. For cars you DO care about and want to keep forever, there are many advantages. Besides cold pourability, the extra safety margin is nice if you live in an area that has very hot summers (100F+), as synthetic will reduce operating temps (coolant and oil temps). There are at least another half-dozen significant benefits which I won't bore you all with, if you're using synthetic now, you probably already know! :p :p


Regards,

Synthetic Oil Lesson
 

My car a 1985 Mercedes 300D turbo with just over
262,000 miles has made the change to Wally World's
Shell synthetic rotella and after about 12,500 miles
no leaks or using oil as before the switch. I change
at 5,000 miles. It must be the condition of the engine.

Wally World did raise their prices this past week-end.
It was $12.xx?. and now it is $18.88 a gallon.

Bill

Yep, and for $18.xx you can get a FIVE quart jug of Mobil-1, which is a better product than the Rotella. Too bad the only suitable M1 for our diesels is 15W-50, which I have only seen ONCE in Wally World. I used to think it didn't exist, but nope, it's just extremely rare. They normally carry the 5W-30 and 10W-30 weights in the 5-qt jugs but those won't work for our diesels...

:p

Re: Synthetic Oil Lesson
 

The price went up, but I am sure that it will come back down again. I have noticed that they do that with a lot of products.

Yes, but at 12.xx for 4 quarts on inferior product, vs 18.xx for 5 quarts of superior product, the M1 is the better deal (since price per quart is almost the same).

Hey, I've said this before so I'll say it again: Chevron now makes a SYNTHETIC Delo400 5w-40. I can get it at a local distributor for $13.98/gallon which makes it a good alternative to Rotella synthetic. RT

Wow, really? I heard they make it, but hadn't heard the price. Might have to check into that. I wonder if it's hydrocracked dino like the Rotella, at that price it would almost have to be...? Hmmm....! Thanks for the tip though. Sorry if I missed it in a previous post.

:)

Here's the MSDS:

http://library.cbest.chevron.com/lubes/chevmsdsv9.nsf/f2f12b5992bba20488256b4c0074a415/4c58e9ef66ea8a3788256712006b3040?OpenDocument

The oil has 1-decene, which is PAO (group IV) oils... However, it says 'or isosyn base oils' which I believe are hydrocracked group II highly refined hydrocracked base oils (comprable in quality to group III 'synthetics') or Group III (isomerized, hydrocracked slack wax)oils, which are more or less the same as Shell's XHVI base oil, which is the base stock of the rotella synth, and are used (with mixed in PAO) for high performance oils like shell helix ultra, the ferrari f1 race oils, etc.

So it loks like a PAO oil with some high quality balance... Gives the benefits of the PAO with the cost savings of the Group III oils. I believe group III synths cant rreach as low of viscosities as PAO stocks, which is why rotella synth barely squeaks in as a 5 weight oil... But thats a story for another day... WHo knows the amouts of each though, it might only be a tiny bit of the PAO oils, with a lot of group III, or vice-versa, or a 50/50 mix. Who knows, MSDSs can be written pretty sneakily, I bet.

Sorry for the babbling, hope this helps though.

JMH

In addition to better engine protection, I have switched to synthetics because I'm lazy. And 'cause I'm (quasi) cheap.

Swapping the oil on my diesel MB or VW is a major hassle on account of the belly pans. At 3,000-mile intervals, driving 1000 miles a month just for work means I must change oil every time I turn around for roughly $30 a shot at the local convenience lube.

Going synthetic means I can safely wap oil at between 5K and 10K miles, costing between $26 and $40 in oil, plus $25 for filters and labor at my MB mechanic (Enrique) -- a savings up to $40 every 10k miles.

Many folks fret over oil (the wars go on, here and at other forums). Not me. Dino has lubed autos for 100 years. Synthetics are simply more practical. Hey, point and shoot.

BTW, I tried finding synthetic Delo 400, but the stuff's even rarer than Delvac 1; you wonder why they even bother making it. I wonder if Mobil 1 -- without its soot retaining abilities -- is as good as syn-Delo, or Rotella T.

Dana, Mobil-1 has good soot suspension abilities, just not to the extreme that the "heavy duty" diesel oils will (Delvac, Delo 400, etc). I wouldn't worry about it until you consistently get over 2% soot via analysis, or plan to push the change interval to 15k+. One analysis at a 10k change wouldn't hurt just to get an idea of what your car produces.

:)

GSXR -

Thanks. Now that I'm forsaking Rotella T (at two gallons per change, sure liked that $13 price), I may go for M-1. Also jotted down the Delvac oil analysis number. Gr8 idea. Plan to limit changes to 10K, but with clean data may go longer.



:p

See my post on delvac1 at CAT dealers (which was due to my reading this thread)... Depending upon where you get your M1, you might be better off going to a caterpilliar dealer or finding a place to get delvac 1 for around $21/gal. I know a lot of places(even most wal-marts) sell m1 for nearly $5 a quart (one that I shop at has it for ~$3.50/qt). The 5qt specials at wal-mart are rare and hard to find, especially in the 15w-50, so for if youre going to pay nealry $5/qt, you might as well splurge and get the delvac1... m1 is a fine oil and will do great in diesels, but if youre paying the same, might as well get something that is superior and designed for diesel operation.
IMO

JMH

Since I am a fan of RedLine stuff I called them and got the name of my local distributor. He sells me 15W-40 that is specifically made for diesels. It's not cheap at $6.50/qt but I'm pretty comfortable going 10,000 miles between changes. The point is sometimes you can look up and call the local distributor of something and they will sell it to you as long as you are willing to by at least a couple of cases.

http://avlube.com/automotive.htm sells Mobil Delvac 1 full synthetic 5W-40 diesel engine oil. Shipped in a case 4 one gallon containers for $81.39 a case, plus shipping.

They also sell Fuel Analysis kits and Oil Analysis kits.

Okay you have me confused!
 

I have been following this thread and like what I hear concerning the syn oil for starting and length of oil changes but I seem to be getting a mixed story on older 240ds and nothing specific on the 115's.:confused:
I have a 1976 240d w/auto trany and unknown mileage (although I suspect a bunch). See "no kickdown on 240d auto trany" for more details.
The car has a little smoke on start-up (sometimes a good puff) and smokes a little going down the road but the harder and more it is run the better it runs and the less it smokes. It has been harder to start in the mornings since the temp has been below freezing and I have had to use the block heater over night but will start easily after work if the day has been at all warm 40-50 degrees.
I would like to switch over to all synthetics (motor, transmission, rearend, ps?) but would this be wise and what should I use in this old and misused (but coming back) diesel?
Thanks

The old 615/616 engine will soot up far faster than the newer ones.

I'd check the soot level after switching for a while (every 3000 miles or so) before running extended changes. I suspect you will find that you need to change it due to soot more quickly than at 6000 mile intervals.

Certainly, if you use more than a quart in a thousand miles I'd not bother to change to synthetic simply due to cost!

Slow starts and running better when hot sounds like tight valves to me -- have you checked the clearance lately?

Peter

Thanks for the help
 

The odometer is dead but in the last estimated 400 miles it has used no oil at all.
I have not checked the valves and was going to wait until I had a manual beside me before trying it but it is on the "to do" list.
What about the other fluids, transmission and so forth, would you switch and what would you use?