Which Pennzoil are you talking about? There is nothing wrong with Pennzoil, but there are several ones. The Long Life is the universal grade which is designed for diesels. If you use any of the others, they will be okay as long as they have a "C" rating. But the CH4 spec found on universal grade oils does a better job of soot dispersal in a diesel and has more detergents to keep the crankcase clean, it is worth seeking this out if you're using it in a diesel. Good luck,

I had someone e-mail me about Penzoil and I responded, but from home and I'm at work now, so wait till I can get home and I'll post the reply.

The reason I use Penzoil is mostly habit, my father used it and I've just kept using it and have had good luck with it. It is a high parifin oil that just got a bad reputation, but parifin is a good lubricant. Changing it often is more important because of that and the high detergent diesel variant helps keep everything in suspension to be drained out when you change the oil hot and change the oil often. When I first needed diesel oil all oils had a "C" rating so I stuck with Penzoil. A few years ago I noticed that changed and I had to go out of my to find it and it became named "Long Life". The reason I've stayed with is that from an engine class I took a while ago I was told you shouldn't mix oil brands cause they may not get along. I've since heard reseach that oil brands are pretty much the same so I've just stayed with them. I also use the diesel oil in all my engines, diesel oil is gas oil but better. My wife has very harsh driving, she drives five miniutes to the train station, and my motorcycle only gets ridden once in a blue moon, until my daughter can reach the foot pegs. So I'll just stay with this oil.

I also use single viscosity 30 weigh. From the engine class I took I was told the additives they add to oil to split the viscosity are bad for an engine, but not as bad as starting a cold engine with thick oil. Living in sunny southern California it doesn’t get cold enough to warrant a multi-viscosity oil. My Mercedes manuals shows 30 weight is okay above 32 F, and that only happens once or twice a year here. Plus the car is in a garage, the coldest it sees is 50 degrees.

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5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)

Mercedes-Benz upgraded the valve guide seals on M103 engines to viton seals during the 1988 model year. In April of 1989, they updraged the valve guides themselves.

Vehicles with upgraded seals alone may go a little longer before oil consumption gets really bad, but not much longer. It is sort of like putting a Band Aid on a really big cut.

Vehicles that have both upgraded seals AND guides seem to go ALOT longer before needing a full valve job. At our shop the average mileage that vehicles with the upgraded seals and guides seem to go before needing a full valve job is 150,000-200,000 miles. On many of these vehicles, we replace seals alone the first time the vehicle starts to use some oil (often around 80,000-100,000 miles), and we find that the updated guides usually have very little play at this type of mileage.

On vehicles with the older valve guides, we often do full valve jobs between 80,000 and 110,000 miles.

We also find on many vehicles like yours that are old in years but low in mileage, that the valve guide seals tend to dry up due to age.

I would replace your valve guide seals only. While you are in there, test the guides for play. I would be surprised if they have any at all at 67,000 miles.

Let me know what you find.

We've all been zeroing in on the valve guides, which Jim reckons are fine (I think).

What about giving the whole engine compartment a good clean-up (degrease it), and then observe the engine block and seals/gaskets for any minor/microbe leak? Sometime it could be a very fine leak - so much so that whatever excess of it burns up with the engine heat.

A probability if we assumed the valve guides are fine?

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... Kerry

126 tailed by a 203, 129 leading the pack.

our 89 190e consumes quite a bit of oil and I have been curious. like jim's, no smoke, good compression.I suspected the valve guides, but no smoke at start up, it hasn't had any problems running. the plugs (which I just replaced) had a weird build up that I've never seen before. kind of a puffy black shiny crust, not the standard oily carbon residue I'm used to seeing on my bike or any cars I've ever had. could this help indicate some chronic problem these cars have?

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German autos!!!
'67 250se coupe
'89 190e 2.6 (gone but I kinda miss it)
'96 c220
'07 BMW x3
'59 0319 diesel Omnibus...the "O"
Italian bikes!!!
'64 Lambretta Special 185 hot rod scooter
'66 Lambretta SX200
'59 Lambretta 250 race bike
'70 Lambretta GP200
'77 860gt ducati
'66 ducati monza

I did mention I did change the guide seals which is why I posted this. I was confidant that was the problem and when changing them didn't change the oil consumption I was confused and came here. I was suprised it had no effect. I'm anoyed at myself cause when I was changing the guides I thought about releasing the pressure and wiggling the valve to see if it was loose, but like I said I was confidant that was the problem so didn't bother. I did notice there was a lot of black stuff on top of the piston but I don't know what that means.

An update on the oil consumption, I had been using 30 weight and switched to the highest viscosity for the motor to 20W40 and the oil consumption droped by half to a quart every 1400 miles which I can live with. As far as leaks go that much oil would make a big mess and the engine is fairly clean although there is some oil around the head gasket. A question is do the intake and exhaust guides wear the same? I'm guessing half the oil is going out the exhaust so it wouldn't bother the plugs. I'm just woried about the catalic converter.

The other place the oil could go is the PCV. As near as I can tell it just pulls through an orfice in the top of the valve cover so there is no valve to act up. Someday I may check it and see what I can see.

An engine burning a quart of oil/1000 miles will destroy a cat muffler in 10,000 miles. it's mostly the phosphorus (Zinc-dialkyl-dithiophosphate anti wear additive) OEMs are after oil companies to reduce ZDP levels to protect cats longer (even if engine wears more).