Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Gilstrap on September 02, 2016, 19:29:36

Title: Can changing oil viscosity cause a shudder
Post by: Gilstrap on September 02, 2016, 19:29:36: I recently changed my oil from 10w-30 (the previous owner always used Quaker State) to Valvoline VR1 20w-50 based on many suggestions from this website. The ZDDP level was the main reason I chose this over others and the heavier weight due to living in a hot climate (South Florida). I liked what I heard from many positive reviews from the readers/posters. During this oil change, I noticed the very important upper oil filter seal was missing (the one where oil won't filter properly without it), so I replaced that too.

Last night was the first long drive I've had since the previous mentioned maintenance. Later on in the drive, my heart fell into my stomach when I felt a pause/shudder upon more pronounced acceleration while in 3rd through 5th gears. I've always read changing viscosity wasn't a big deal, but now I am doubting this and feel like I need to drain this oil and go back to what it had. Has anyone ever experienced this before? A simpler explanation would be a differential issue, but the coincidence in timing has me thinking otherwise. I would love to hear what others think.
Title: Re: Can changing oil viscosity cause a shudder
Post by: Benz Dr. on September 02, 2016, 20:03:30: I very seriously doubt it.
Title: Re: Can changing oil viscosity cause a shudder
Post by: Cees Klumper on September 02, 2016, 20:42:39: Should not have anything to do with each other. Purely coincidental. The shudder is caused by other things, like ignition or fuel delivery.
Title: Re: Can changing oil viscosity cause a shudder
Post by: Tyler S on September 02, 2016, 23:45:46: The only very very remote possibility of the oil change being involved would be the viscosity of the oil affecting the counterweights in the injection pump. I believe 69 had a crankcase oil feed tube. Could be wrong. Like i said very remote but we have all seen stranger things with these systems.
Title: Re: Can changing oil viscosity cause a shudder
Post by: Gilstrap on September 03, 2016, 18:22:55: Thanks everyone for the input. I've been reading the site for several hours this morning trying to decide on the next step. I, too believe it can't be the oil viscosity change, but since it's the cheapest test I'm going to drain it (save it since it has less than 50 miles) and put 10w-30 back in to see what happens. Now, to decide on what to purchase and an zddp additive. I've written down all the recommendations for different brands and types. It can surely make the head spin.
Title: Re: Can changing oil viscosity cause a shudder
Post by: 280SE Guy on September 04, 2016, 11:15:50: If you determine that the viscosity is the issue Valvoline VR1 racing oil is available in 10W30. I usually buy a case from my nearest NAPA store, they don't stock it but can have it in a day.
Title: Re: Can changing oil viscosity cause a shudder
Post by: ejboyd5 on September 04, 2016, 11:57:49: You are wasting your time and money with an oil change. Look elsewhere for the cause of the malfunction.