Flushing Oil
 

No, its not a post about the merits /demerits of synthetic oils or the use of a Topsider v draining , but it is related in a way. I am about to change the oil+ filter in my car, recommended interval of 9k miles.
In previous invoices from my mercedes-benz dealer I noticed a consumable item OIL FLUSH. I assume refers to the use of a flushing oil to clean out the system before putting in the new oil. Does anyone know if this is standard MB practice for the longer oil change intervals used now? Is this practice necessary/desirable or merely the icing on the cake. I see no mention of it in the service manuals. If this is recommended,who manufactures this flushing oil and where can I buy it and how do I use it? I would be grateful for comments.

Forget about the "oil flush". Just change it hot and change it often and you will be fine. Make sure you are running a quality synthetic if your change intervals are going to remain at 9k.

I don't know of any manufacturer that recommends an "oil flush". To me this sounds like something they do to pad their profits.

Grober,

You just received two very accurate responses from these guys. The very best flush that can be done to any engine is frequent, (9,000 miles is anything EXCEPT frequent) hot, overnight oil drains with a fresh filter every time.

Making up for a lack of frequent oil change by flushing is IMHO a "BAD, BAD, BAD" plan. Flushing is a step you take with a neglected engine. It cannot reverse any wear that was incurred by excessively long oil change intervals.

I don't care what kind of oil goes into an engine. I don't care if it contains KRYPTONITE, it MUST be changed often if you are seeking long engine life. The reason you change the oil is that it is the only means you have of cleaning the inside of the engine. Additionally, regardless of the oil used, there is particulate matter, not trapped by the oil filter that builds up in the oil. This particulate matter accelerates wear, particular on timing chains.

Using Mobil One is great, but you still must change it hot and change it often. Also, you did not say what car you are talking about. If this is a diesel, you should use a Universal Grade oil. If you want to use Mobil One, use Mobil Delvac One which is a Universal Grade. These oils are blended with additional additives for soot dispersal, very important in a diesel, but unnecessary in a gas engine.

In fact if it is a diesel, you would be better served using a Universal Grade oil than regular Mobil One. Mobil Delvac One, however, is the ultimate Universal Grade.

Best of luck,
Change oil hot and change oil often,

As it has already been said, the secret for longevity is proper maintenance.
Oil change interval is not, for a Mercedes, proper maintenance.
I'd rather have my engine bath in a 4,000mi old cheap mineral oil than in 9,000mi old expensive synthetic oil.
And forget about the flushing oil, total waste of money with a shorter oil change intervals.
JackD

Jack,

Very well put.

Have a great day,

Thanks to all the guys who replied . Hot and often. I got the message!!

Well, to each his own. No way would I trade a cheap 4k mineral oil for a good 9k synthetic. I'd wager that the synthetic is doing its job much better than the mineral. But this is an argument that can't be answered here. The bottom line is that changing more often is better than less often, whatever you are using. ;-)

I'm not an expert, but it seems that most modern brand name oils today would be good past 4k miles in a modern and otherwise well maintained engine. I'd even venture to say that 9-10k miles on regualr dino juice is ok (but why would you at .99/qt). Synthetic is even better. IMHO, the weak spot here is the filter. Have you compared a filter with 4k and a filter with 10k? I have not on my MB, however, I have on other vehicles. The 10k vehicles filter is by far more crapped up(technical term) and restricted than a 4k filter. Cutting a couple open will prove that to you.

I plan on at least changing my filter in 4-5k intervals. Seems relatively easy and cheap to do on my C320. I haven't yet decided about waiting or not for the fss (10K+) to do the oil itself.

God, I hate motor oil threads :-)

Brian

Brian, I hate motor oil threads too but I hate them because there so much misconception/false information/personnal unfounded opinions/tales/hear-say. I spent over 25 years of my professional in the lube business, developping/testing/blending/comparing/analysing all kinds of lubricants for an with engine manufacturers/ aftermarket customers, car makers. I think I have a little bit of knowledge in this department.
Motor oil, whatever make/grade/type/ application needs to be replaced at prescribed interval not only because it has lost it's some lubricity, but because it is dirty and because the additive package has lost a good portion os it's properties. After 4 to 6000mi, motor oil becomes a soup of oil, water, sulfuric and other acids, ash, gasoline (diesel) gum, soot, varnish, carbon, metal particles, silicate and many other contaminants. It is the combined ill-effects of those contaminants that are harmfull to an engine.
A $25./quart super extraterrestrial synthetic oil will be as bad/contaminated as a 79c/qt oil.
Synthetic oils have properties far superior to mineral oils for certain applications (transmission/differentials/grear box/ hydraulic systems) where oil operate is in close confinement (not exposed to external contaminants) but for and engine, a fresh good grade mineral oil is by far more protective for your engine than a 6,000miles old high priced synthetic oils.
I must say oil companies have had some very successfull marketing campains to promote their higher price synthetic oils for engine.
JackD

What Jack says weighs heavily with me, because it's exactly what another expert - Dr. Shirley Schwartz, of GM - said in a talk I listened to some time ago. Shirley is one of these people that has access to some of the best data available on oil testing in the automotive industry. Nothing like hearing it from experts!

Yea Jack,

I agree with what you said about the contaminants being the biggest problem. You obviously have more real world experience in this area than I do. The point I'm trying to make is that the filter is the component that removes the contaminants. Once the filter is clogged with the "soup", the stuff bypasses the filter and floats around in the suspension. I put on a 1 micron bypass filter on my previous ride. It is amazing how clean the oil looked and tested compared to just the stock filter. It not only trapped solids, but also water and fuel (so it claimed). Being the anal oil changer that I am, I still changed my Mobil1 at 4k intervals. I guess it's just cheap insurance and it gave me something to do:-)

Now, on synthetics. From what I understand from an uncle who worked for a large aircraft engine manufacturer, synthetics are not necessarily better lubricants, but they are capable of holding more particulates in suspension. This was based on their testing as it pertained to piston engines, not turbines so I guess it's sort of applicable. Again, I think the key is in removing (filtering) them.

In any case, change the oil and filter frequently and you'll be safe !

Boy, I hate oil threads :-)

Brian

Flushing has its place
 

Wow. I will no doubt change my thoughts about flushing but I feel there still is a place for it. I just bought a 1983 300SD Turbo Diesel and have no idea how well the the engine was cared for. A flush that drops lumps or thick sections would require further investigation. I ordered lower oil pan and valve cover seals just in case I have to clean slug from the bottom of the pan. Yes if I owned the car forever or knew its history a flush may not be that beneficial. For a new used car, I have to go with it.
Separately I read in the manual that up to a quart of oil can be held up during an oil drain. Don't like that. I'm thinking it could be the oil cooler lines. The oil change procedure did not look like it would drain that section. Anyway I have started spraying penitrating oil on the hose fittings.
In surfing the manual I noticed oil spray nozzles pointing up to the pistons. So how often should those be checked? This could be a place a flush could help. Any buildup around the nozzle would hurt the spray pattern. The book said pluggage of a nozzle can ruin the engine but gave no info on when to check.
Anyway, I may not flush all the time but never or not after acquiring a new used vehicle, naw I'll still do it now and then.

Mark W