Hello Again,

Went about changing the oil in my S5oo today, When I bought it about a month ago the selling dealer told me the car had been serviced as the service interval had been reset. This morning as I was vacuuming out my car I saw a wonder full penzoil change sticker under the driver seat. So it bothered me that it was not mobile 1. So I changed it myself and the oil came out black as night. I also notice there was what seemed to be a lot of sludge at the fill neck a top of the motor. Is this normal? This S500 has about 80k miles on it and most of it looks to be city driving. After I changed it I noticed a big difference in response.

Is there anything I can do to prevent sludge or remove sludge? I want to change it again in about 4500 miles before going to regular 7500 miles intervals.

Another quick question, I have been reading a lot about flushing the coolant as I see some corosion on the overflow tank. Is this normal? Or will I be doing any harm in changing it sooner. I plan on a doing a 2600 mile round trip in her come Jan, and I dont want to over heat as I make the Texas Desert a cake walk.

 

If the dealer wasn't an official Mercedes dealership they likely used the wrong oil or lied about changing it at all . Most used car dealers just press the reset button and say it was serviced

Yes you can change the oil and coolant early and make sure to use correct fluids

 

My local MB dealer use Mobil 1 5W-40 Fomula M now with a can of BG MOA engine oil suppliment. So I do the same way when I do oil change. I do not see any sludge at all.

 

Briefly, combustion creates oxides of nitrogen, that when combined with water in the crankcase, form acids. Oils have additives that neutralize those acids. When the additive is depleted, those acids combine with the oil to form sludge.

So, the MB 229.5 standard for oil has rigorous additive requirements. An oil meeting that standard will last a long time because the additive package is strong. You can choose whatever you like for your engine, but my recommendation would be the Mobil 1 0W40. It meets 229.5 and is relatively cheap ($26/5QT jug at Wal-Mart). You can pay more, but you will not find a better performing oil.

I use it exclusively in my S600. Here are two Used Oil Analyses that I've posted elsewhere. The oil does a great job.

http://www.bobistheoilguy.com/forums...S6#Post3764692

http://www.bobistheoilguy.com/forums...Number=2982174

For your car, you may have sludge, you may not. Oil color doesn't indicate acidity. Best thing to do is simply change it with the M1 0W40 and let the oil clean the engine. Solvents and additives are not good for your engine. Clean it gently and slowly using the additives in a good oil. An early change on your first run of Mobil 1 would be a good precaution.

 

Thanks for your input guys, I did change it out with MB approved oil. Pretty big difference in smoothness. I will change this round of oil out when I get back from my very long road trip in my S.

 

+1 for the Mobil 1 0W-40 have been using it for years with no problems of any kind. Walmart is the best place to buy it.

 

+1 On Mobil 1 0w-40.

But I have moved on to Mobil 1 Formula M. Got them from a mech I know. $5 a quart, super deal considering that he carries Mercedes oil for $6.

 

I agree, bur MB has changed to Mobil 5 W 40, and will not sell anymore the 0 W oil.

 

Change it dat mobil onez, den pimp around fo 100 milez. change demz oil again. Problem pimped yo!

 

Huh???

Translation?

 

Ugggg!

Translation:
"Change oil to Mobil1.
Drive around for 100 miles.
Change oil again.
Problem gone."

(This translator does not agree with the 100 mile duration suggested in the comment, and rather suggests 3k to let it do its job melting down any sludge in the valve train. This translator also regrets the slow downward spiral of proper English on a technically informative forum, as more 18 year olds listening to too much rap music can afford S55s and think everybody else want to fashizzle their nazzizle yo. Peace out.)

 

Lol!

From what I have read, He has much sludge buildup. If he drove for 3k miles he would be running the excess sludge for that long. Maybe run it for 1k miles. Though I still believe 100miles would be optimum to allow the detergents to run though the system and scrub up the sludge. It may cost a bit in a filter and oil but at least your engine will be clean.

 

I suppose I would agree to an earlier change. Around 1k. But sludge takes a long time to dissolve into fresh oil, even if it is synth M1 0W40.

My original estimate was based on seeing my son's friend's BMW535 respond well from running a few K with a fresh change after he bought it used with some sludging under the valve cover. He still has some.

The proper treatment is to pull the valve covers and pan off and dig it all out, clean with a solvent, run 10 miles, change oil.