5 minute flush? Full synthetic oil?

[William73]

I'm about to do the first oil change in the '87 300E with 156k I just bought.
I like to use a can of 5 minute flush before I change the oil. Then again, I usually do this in an old International, not a Mercedes-Benz.
Would it be a bad idea to do this?
Also, I'm thinking of putting in full synthetic oil. Any suggestions on which oil I should use? Is there a good oil additive I should put in it?
I'm also planning on changing the tranny oil and filter. Is there something I should do before I drain the tranny, like a 5 minute flush? I would like to have it nice and clean when I put the new filter in.
I'm looking to get long life and good economy out of this car.
Thanks for any help you may have for me.

[Jim B.]

My personal preference is Castrol 20-50 (though a different viscosity may be preferred in Alaska winters) and a Mann oil filter.

A new or first time owner should take the vehicle for an ATF service to a Mercedes Benz dealer or better yet to a trusted Mercedes Benz only, independent garage. A little too complex for even the ambitious DIY guy to try as a brand new/first time Mercedes Benz W124 owner. (Possible DIY risks far outweigh the benefits here, )

When I was in Portland about 8 years ago, I was referred to Burback Motors, they are east of downtown across the river, below Lloyds Center, as I recall.

The owner (Mike Burback) even had a W124 AMG as his personal car, so his shop should be perfect. The prices are VERY reasonable too.

[William73]

Thanks, I'll be in Portland tomorrow.
What could possibly go wrong with a DIY ATF service?

[Peter Guenther]

It depends on how good you are, you should drain the torque converter, change the filter, and again torque the pan bolts. There have been some that ovetighten them resulting in leaks from warping the pan.

[jlomon]

Originally Posted by William73

I'm about to do the first oil change in the '87 300E with 156k I just bought.
I like to use a can of 5 minute flush before I change the oil. Then again, I usually do this in an old International, not a Mercedes-Benz.
Would it be a bad idea to do this?

My only concern around the flush products is that they can expose pre-existing leaks in the motor by clearing out whatever buildup may be masking the leak right now. I'm not saying your car has this as an issue, but if it does, you'll start to see leaks appear.

I would suggest you consider the use of Shell Rotella 15w40 because this product has a much higher concentration of detergents in the additive pacakge than standard oils have. This can help clean the inside of your motor (and prevent additional buildup going forward) without using the more aggressive 5 minute flush type of product.

[d.delano]

Flushes are unnecessary. Waste of time and money, and you could possibly cause a leak on an old engine. Just drain and fill with synthetic and let the detergents do the cleaning gradually. Use the Rotella synthetic 5w-40 and something good like Redline D4 in the transmission and make your life easy.

[babymog]

Mobil 1 has been a favorite with those interested in cleaning out the system. I personally like Castrol Edge a little better for easily-obtainable class IV synthetic, RedLine is the best IMO but not available many places, Amazon.com comes to mind.

Look out for "full synthetic" labels, many of them are hydrocracked dinosaur oil, aka: Class III synthetics, different than the old definition of full synthetics. Mobil 1 for example: Turbo-Diesel & Truck is what I run in my gasser and diesel Mercedes E320s, a class IV synthetic, as is Mobil 1 Extended Performance, but the regular Mobil 1 oils are now downgraded and re-formulated and are only Class III synthetics like many other cheaper-basestock oils including some of the Amsoil products.

I do not believe in engine flushes, there is risk. Good oil like Mobil 1 TD&T will clean out that engine in a change or two and is gasoline engine rated as well as diesel, plus the 5W-40 rating works for your climate.

In the transmission, go syn if you want to, I see less benefit there unless you're running it hard. Do NOT NOT NOT have the trans fluid changed by anyone with a flushing machine type of change, unless you want your next stop to be a transmission repair shop. My friends with transmission shops love businesses with those flush machines, tell me that they generate a lot of business for repair shops. It is a quick way to do a change, not a good one, the proper and safer way is to drop the pan, keep it CLEAN with no lint and NO PAPER TOWELS, new filter and gasket, drain the torque-converter also, don't over-fill.

[William73]

Thanks, good info. I think I'll stay away from the 5 minute flush. I plan to do my own ATF oil/filter change. I have experience and tools. Working on your own car is a good way to get to know it. This will be one more thing to add to the list of cars I have worked on and things I have done, if I mess it up and have to fix it then it will be two more things I have done.

[ps2cho]

The "flushes" generally do more harm than good...

ATF is very easy to do. The hardest part of the process is finding the Torque Converter drain plug. Easiest way is to "carefully" turn the TC with a large screwdriver otherwise you'll need to turn the crank and have someone under the car watching until it is visible.

There was a great tip in my "E-Class Bible" that says after draining the pan, only unbolt the frontmost 2 bolts, then SLIGHTLY loosen the two rear and let the pan tip forward naturally as this will save a boatload of remaining fluid from spilling all over your floor.

[Hit Man X]

I agree, skip the flush and just change the oil.