Why is it so important to clean the inside of your engine?

If you have been changing your oil when you should, there shouldn't be any sludge in your oil pan, and why kick it around if there is?

All you need is one oil port to a rod plugged and you're finished!

If you go with Amsoil, I would suggest:

AME 15w-40 is their full synthetic diesel oil. Many people can use it year around depending on their climate. (Keep in mind there are people using Mobil 1 15w-50 in Northern Minnesota winters.) Its also the most cost effective.

AMO 10w-40. A bit more costly than the 15w-40 and marketed towards gas cars, its CI-4 diesel rated and runs fine in diesels. I know several people using it.

AFL 5w-40. More costly than the 10w-40 and marketed towards Europeans cars, its CI-4 rated. This is a new product.

Regards,

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Brian Toscano

I did a couple thorough dino oil changes on my cars, then switched them to synthetic. I don't trust those engine flush products and IMO they must put too much stress on the engine because they severely reduce lubrication. I just flush my engines with a quart of fresh engine oil at each oil change. This is really effective at getting out a lot of the sludge at the bottom of the oil pan.

I think the idea that synthetic oil will loosen up sludge more than dino oil is a myth. I really doubt synthetic has a greater ability to dissolve sludge. The difference is that it won't add more sludge like dino oil will.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

If I remember correctly Amsoil has been around longer than Mobil 1.

Andy

If I remember correctly, Amsoil buys their base stock FROM Mobil. :p

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Chris
1985 300SD - 'Grace' (198K mi.)
2018 Honda Civic Sport
2018 Honda CRV LX
2010 Honda Fit Sport (RIP)
2013 Honda Accord Sport (Sold)
1996 Lexus LS400 (Retired)
1995 Ford Contour SE (Retired)
1976 Porsche 914 (Sold)
1972 Datsun 240Z (RIP)

ck42

Right, Amsoil and Mobil use the same base stock. I have been using Amsoil 15/40 for some time. After I rebuilt an "80" engine and put it in my wifes 240d there was a small oil leak from the aft crank seal. Now, 10K and a year later there is NO leak. I switched back to Amsoil when the engine had 1.5 k. I use their 100 : 1 two cycle oil in my power saws. Good product

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I'd not bother with an engine flush, but when changing from dino to synthetic, change the oil filter (only, with top up of oil) at about 1000 miles after swtiching. It will probably be full by then, with sludge and varnish released from the engine internals. After that extra filter change, change at 6000 or so intervals with filter change.

On a worn engine, ecesssive leakage is also possible from worn seals "protected" from lots of oil moving past them by crud, but it's likely you will not have this problem on a well maintained engine.

If you already have oil leaks or consumption problems, they may get better or worse, depending on source. If you have excessive blowby from crappy rings stuck with crud, the synthetic may free them up an cure the problem, or it may just "pump" worse. Some seal leakage may be cured by the synthetic as it contains a softner/sweller additive to counteract the shrinkage effect on old, dino oil soaked seals.

The seal shrinkage problem was discovered in the 70's when Mobil (and Amsoil) first started marketing synthetic oils. The seals absorbed the dino oil, swelled, and wore to fit, so to speak. The synthetic "unswelled" the seals, and they leaked. Old history.

My take is that I won't bother with synthetic on an engine that uses more than a quart in 1500 miles as it costs too much, nor do I sue it in an engine that has front or rear seal leaks for the same reason. Otherwise, just change the oil filter an extra time and you will be fine.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

The "MOST" important thing is to change the oil regularly! I also use RotellaT 15-40 and have had good results with it.

I'm very weary of any oil flush. If you have a sludge or buildup problem it's better to drop the pan, clean it and the pickup and change the oil more often with a quality product.

Unless the PO searched high and low for non-detergent oil or never changed it (fairly unlikely on that expensive a car, but you never know!), you won't have an actual sludge problem.

However, dino oils, especially changed on "factory" guidelines (7500 miles) will build up considerable varnish and some hard sludge that will partially dissolve in synthetic oil. This stuff plugs the filter pretty fast on the first filling of synthetic, then is gone.

I use synthetic oil in my lawn movers, too -- reduced the oil consupmtion quite a bit.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks all again for the responses.

Seems like most of you feel that an engine flush is unnecessary and may actually harm the engine slightly. As a result, I have decided not to use it then.

I've been running it on plain oil and for 2800 miles, it hasn't consumed a drop!! As a result, I'd say I have no leaks. I'll bear your advises in mind as I perform the change.

Now, how about switching to synthetic differential fluid and synthetic ATF? Any comments on that? Thanks!

I have had Mobil 1 75W-90 in my diff for 2k miles and no problems.

Now in the transmission, I don't want to put a new type of fluid in a 16 year old 235k miles automatic. I'm sticking with the regular stuff. Now when I get a rebuilt one, it will get Mobil 1.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Well my MB has synthetic from front to back with no real problems. In the motor first time I ran a semi-synthetic and ever since full synthetic M1. The semi-synthetic did start a leak, one which should have exisisted anyway. It was just loose bolts on the filter housing. I put it in the rear end, it weaped a little before, it weaps a little after. I put it in the tranny and it feels a little less connected than it was before, not really slipping but a little play with RPMs versus speed. I have it in the power steering and brakes with no ill effects. One maybe two problems at most, IMHO well worth converting. As a matter of fact this has been on my mind lately. Some people criticize them because they sound so unprofessional but at .1 microns surely it should help stop the wear.

Motor: M1 Synthetic, probably Amsoil after I run my stock out
PS: M1 ATF Syn
PB: Valvoline Dot4 Syn
Rear diff: Redline 75w90 syn
Tranny: M1 ATF Syn
Fuel: mix of #2 and soybean oil (so I guess that is synthetic )

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

I have used SYN's in my gas burners but not in my diesels. I have found a VERY good dino oil I like for my MB diesels. BRAD PENN.
Hard to find though. Only find it at small distributers in Atlanta area. It has all MB ratings I guess it is for it's big truck line but when I put it in my 300K SD I add no oil in a 4000 mile change. Unlike other brands. Rotela is the worst for burnning it like fuel.
Goood luck oil is a bad subject here i have never replyed on it and I have over a million miles on all of my cars and I have owned most of them the majority of there miles. Good Luck

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I like to Drive
77 Celica GT 295000 sold
80 Volvo DL 168000 sold
84 Volvo GLT 342000 Real fast sold
86 Crown Vic. 258000 cheap to keep
84 Ford Van 6.9 360000 sold Great
88 Ford Dulley 7.3 311000 still have
90 Ford Van 7.3 235000 sold great
92 Ford Van 7.3 223000 Excellent still have
82 300TD 1st Benz Great Car 205000Sold
85 300SD 245000 What a ride
84 300SD project car with son, Rod knock
85380SE What a RIDE
90 420SEL Nice Ebay Addition Great buy

I think it is. A C – rated oil changed every 3000 miles with filer is fine.

I switched my 81sd from dino to Mobil 1 Truck and Suv when it became available. I read here where that is repackaged Delvac 1.
This is a high mileage car that has drunk dino forever. Happy to report oil consumption is at a minimum. Ran it over 2300 miles before it used its first quart.
I did do a couple of quick oil changes with the dino to at least try to clean it up first, and I repaired a leaky tensioner gasket before making the change over. That cleaned up my garage floor also.