Oil consumption on 1990 190e 2.6 - PeachParts Mercedes-Benz Forum

Darin Darlingto · #1 09-11-2002, 01:52 PM

I know this subject has been covered pretty thoroughly, but I couldn't find much on my particular problem. I bought a very nice 1990 190e 2.6 early this year with 84,000 miles on it. Owned by elderly couple since new, and their driving habits could be part of my problem. Within a couple of months, discovered that car was using one quart of oil every 800-900 miles. Having driving mostly japanese cars in the past, I was a bit alarmed. After checking on this forum, I learned about the likelihood of bad valve stem seals, so I had them done about one month ago. Just before this, I changed the oil and put in Valvoline Maxlife 20W50 to help address the problem. I haven't driven the car much since the oil change/valve seal replacement, but it appears to be using at least as much oil as before, maybe even more (one quart in 600?). Now I am really feeling bad. Compression tests shows all six cylinders between 145-150 and leakdown test shows all six between 14-20%, which I was told was ok. Also was told by mechanic that spark plugs looked fine.

Where do I go from here? I use a private mechanic who has a good reputation with German cars. He is the one who did the valve stem seals for me. Just out of curiousity, I called the local MB dealer to ask them about this problem. Service manager stated that if the seal replacement didn't do the job, then it is possible that the valve guides are damaged and I may need a complete valve job. I questioned this as the car only has 85,000 miles, but he said if the car was driven on mostly short trips, carbon buildup could damage the guides even with low mileage. He also stated that by using the Valvoline Maxlife oil, I may have cleaned out some deposits that were actually helping the car not use as much oil, thus, causing an increase in consumption.

Anyone have any thoughts or suggestions? Short of a valve job, should I try different brands/viscosities of oil. I have heard that these cars react differently to different oils. Any comments good or bad on this Valvoline Maxlife product?

#2 09-11-2002, 02:09 PM

I own a 1989 2.6 and ''I've been there, done that''
At 90K the car satrted to drink oil. As you suggested, I tried different grades/make of oil (expensive synthetic, mineral, snake and everything else in between. I also tried additives all of which made no significant change. When it consumed 1qt/600mi, I decided to have the valve steam seals replaced. Oil consumption was reduced to 1qt/1,500-1,800mi, which is very good. It stayed there for a while, but soon started to drink oil again At 150K, it was 1qt/1000, which is still very acceptable.
At 175K 1qt/750mi
At 200K 1qt/ 600mi.
At 215K, I had the valve job done.
Since then (now at 235K) the oil level barely move between oil changes
I don't think the problem is related to the type of driving. I run my car pretty hard and had exactly the same problems you have. Oil changes have always been at 3,000mi. This is a built-in weakness of those engines. You can try new valve seals (maybe it will work for a while) but eventually, you,ll have to address the valve guides.
Good luck
jackD

Darin Darlingto · #3 09-11-2002, 02:26 PM

Thanks for the reply Jack. Like I said, I just had the seals done and haven't driven the car much since, but it appears the problem may not have gotten any better. I'm going to keep monitoring it for a while and might even try a different oil, so we'll see. I would be happy with one quart in 1500-1800 miles for another 50,000 or so before needing a valve job, but I'm not too excited about doing one right now with only 85,000 on the clock.

I assume that if my guides are bad, that means a whole valve job, or at least that's what I've heard. What can I expect to pay in U.S. $? This is my first MB and I really love driving it, but I paid a premium price for it and have already put about $1000 into it. I'm just a poor government employee and depend on the car as my everyday driver. Things are adding up!

Jim Anderson · #4 09-11-2002, 03:06 PM

I had the same problem. I put new guide seals in but that didn't help. I switched to 20w-50 and it slowed to an acceptable qt/1200 miles. I had my spark plugs read and they showed some detonation that could be caused by the oil. It was suggested to use synthetic cause it doesn't burn, and stick to premium gas.

I've heard about de-carbonizing on this site. Do a search for info on it. If it has been carboned up by old people driving habits it may help you.

blackmercedes · #5 09-11-2002, 03:50 PM

If it ain't broke, why spend money and time fixing it?

First, your car is 13 years old, regardless of mileage. Ignore the odometer, as sitting is WORSE for a car than driving it.

Next, your engine seems in good shape. The compression/leakdown tests came out within spec, so why are you fretting? Our 1990 190E 2.6 uses a litre of oil every 1500km's (about 900-1000miles) and it's running well. Until something happens, I'm leaving it well enough alone.

If your plugs are not fouling and the compression is good, you're probably best off just adding oil every few tankfuls...