I bought this 95 E320 Wagon in early June so it was already quite warm in Ohio. It never made any valve or lifter noise. Lately the mornings have been in the low to mid 40's F. On cold start I can hear what I think is a lifter for 3-5 seconds. Should I be concerned?

When I did the first oil changes in June and July I used Mobil One 0W40. Last week I used Mobil One 10W40. The service records show it had been using Kendall GT1 20W50 (car was from Alabama) which seems thick for the temps here.

Could the Mobil One be too thin? Or too thick?

Thanks,

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Tim Benner

00 ML320 170K
95 E320 wgn 160K

Tim, to the best of my knowledge original fill for the 124 cars was 15W40 mineral oil. I run Mobil 1 15W50 in our 124 cars year round without any problems. Mobil 1 15W50 pours at -49 degrees F per the label ... so it shouldn't cause any lifter problems.

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Fred Hoelzle

Thanks Fred. So maybe the car is developing a 'tired' lifter. It may take some experimenting between thicker and thinner oils to find the one that will pump the lifter up faster and protect it for that first 3-5 seconds.

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Tim Benner

00 ML320 170K
95 E320 wgn 160K

Tim, dirt is likely causing the lifter ticking. The cleaning additives in the Mobil 1 oil should clean things over time. A road trip at highway speeds may help resolve this condition quickly.

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Fred Hoelzle

Fred, The ticking started right after a long-ish road trip ~600 miles of interstate. Perhaps some dirt worked loose from one place and deposited in the lifter. It only ticks first thing in the morning when it is completely cold. It did it again today when it was mid 50's F.

It is already about 800 miles into the oil change I did last week. I hate to waste oil but maybe I should change it back to Mobil One 0W40 and see what happens. It ran tick-free all summer on 0W40.

I appreciate your help!

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Tim Benner

00 ML320 170K
95 E320 wgn 160K

Tim, rather than change fresh oil I'd expect things to sort out with time. Mobil 1 10W40 is the lowest viscosity oil I'd use in a 1995 E320. As I mentioned previously I run Mobil 1 15W50 year round in our 1995 E320 without any ticking of the hydraulic lifters. I run Mobil 1 0W40 in our 1998 E320 because, from what I understand, that engine has tighter tolerances ... I also adhere to oil changes every 7,500 miles instead of relying on the FSS computer which suggests oil changes in excess of 10,000 miles.

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Fred Hoelzle

My 94 E320 wagon was making what I thought was valve noise on start up. Closer inspection revealed that the air injection pump was making noise. I've also read that the older style belt tensioner shock absorber thingy can rattle a bit.......

J. M. van Swaay