That's the ONE!

Hello everyone. Just to update you, I dumped the mobil one out last night, and put in the castrol GTX 20-50. Within about 15 miles, the noise is gone.

I am dumbfounded why it did this, but wont make the mistake of using synthetic oil in an older motor again.

Ed, I agree the noise is ambarassing, even though perhaps it offers better protection. Perhaps one of the lifters is going bad, and the increased flow of the mobil 1 exploited it. Just a thought.

Thanks to all...

-Andy

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93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K

Mobil 1 will have lower viscosity at low temps, higher at high temps, than dino oil, so I suspect you have crud in the oil passages, along with some wear in the adjusters. The thicker dino oil masks the wear in the tappets at low engine temps.

If it bothers you, stay with the dino. If you want to change, you will need to run the Mobil 1 for about 1000 miles, then change it and the oil filter, the filter and oil will be full of crud that has dissolved.

The lifter noise may go away with extended use of Mobil 1.

I had rather severe lifter rattle in the 300D, but new o-rings on the oil filter shaft and some miles on Mobl 1 15W50 cured it.

By the way, if you have an oil filter canister with a long shaft that goes from the lid down to the bottom of the canister, check for the presence of two small o-rings toward the bottom. If they are present, change them (they are not in the oil filter box). On the diesel, these hold oil in the lifter gallery, and when they leak, the oil drains out overnight, leaving you with noisy lifters. Won't happen nearly so much with dino oil, it's thicker cold.

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!

I would agree. I seriously doubt Mobil-1 is causing your noise problem. Much more likely to unmask an existing problem.

I switched to Mobil-1 at 80,000 miles with no problems whatsoever. And no, 15W-50 isn't "too thick."

What's your oil pressure? The other possibility is the well-known oil tube problem in the M119 engine which presents as noise in the valve train and lower than usual oil pressure.

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Steve
'93 400E

I've got a 1994 C280 that now has approx. 77k miles on it. I used Mobil 1 synthetics on previous cars, but was able to start using the oil with much less mileage on the car, so I wasn't worried about leaks starting. I got this car three years ago with about 58k miles on it. Has anyone with an M104 engine had problems switching to synthetic at this point or later? My car can sometimes sit in the driveway for days without use, so I'd be much more comfortable with the faster flow of oil to the top end that a synthetic could give me. I just don't want it to give me oil leaks in the process. I've only got a little bit of sweating on the front silver seal now.

Any input would be appreciated.

Jonathan

Make the switch and you'll be fine. There is usually no leakage problem with modern seals.

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Steve
'93 400E

I notice the same with my 300CD too. The engine is definitely louder and more metallic sounding now. Once I'm back in Boston I'm gonna change it back to dino oil.

btw, I use Mobil Delvac 1 for the diesel.

The E420 is using Castrol GTX and I dont think I'm gonna go to synthetic.

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2008 BMW 335i Coupe