mdwalker2

I'm a newbie, this is my 1st MB. I bought it in NY and drove it to Houston Over the weekend. Made the trip fine, but I had to put a quart of oil in every 600 miles. When I got home I had it running and was checking it over when I noticed a light spray of oil coming out the exhaust.

When at an idle oil pressure indicator holds between 1 and 2, when driving it stays pinned on 3. Thare is no smoke, no knocking, and no external evidence of a leak on the engine that I could see. I'm assuming there is a leak at the exhaust manifold, but how do I verrify/repair?

STLe320

At idle, mine too is right below the 2...my check engine light has came on as well...any ideas for either of us?

shdoug

Welcome to the forum!

Oil pressure reading anything above 0 at idle is normal. It will be higher in cold weather than in hot weather due to the oil being thicker and slower to squeeze out of the main bearings. It should always be at 3 when above 2000 rpm or so. What you describe with the oil gauge is a sign of healthy bearings.

Are you sure that it's not a spray of water vapor from the exhaust, which would be normal? If oil were in the exhaust pipe, there would be smoke so thick after driving for 5 minutes that you would get fined for gross pollution, if the officer could even find your car through the smoke screen. I would be willing to bet it's not oil vapor. The normal condensation mixes with carbon and makes a black sooty looking vapor from the exhaust.

These engines are known to develop leaking valve guide seals which causes excess oil consumption. Usually leaky valve guide seals will cause smoke at startup and sometimes at hot idle which those around you will notice but you may not. I think it requires a valve job to correct if it bothers you enough. You could buy a lot of oil for $1200, though. If it's not smoking I wouldn't worry about but that's just me.

Rio Z Lander

all i have to say is your cars might be burning oil mine dose and i need to add oil ever 2 to 4,000 miles mine sit at 3 all the time unless im running low then it sits a little past 2 1/2 or if i take a hard turn it drops to 0 and the shuts off the motor

Rio Z Lander

a good way to know if your car burns oil is run the motor for a bit. turn it off and take off the oil cap and look in there if smoke comes out your car burns oil.
all cars do it when they get old. if alot of smoke comes out get it looked at can be a warning that a bearing is going bad or that a part is going bad.

mdwalker2

Thanks for all the responses.

Shdoug, you are absolutley correct, furthur inspection revealed it to be water vapor with soot dissolved in it. I pulled the spark plugs and they suffered from Gap erosion as well as all being coated with the same deposits some of the other posts displayed when talking about leaking valve seals. I replaced the spark plugs (with cheap platnuim ones) and performance is up some. It is currently running 10W30 oil, when I get back to San Antonio tomorrow I'll change the oil and put in 20W50 to see if that helps.

I did not notice smoke when I pulled the oil cap.

How hard is it to do a valve job yourself?

My father in law has all the tools I should need, but swears he will only work on Fords so other than a bit of guidance I'm on my own.

Jackd

It would be extremely surprising if you needed a valve job at such a low mileage.
I think you're trying to fix a non-existant problem.
At worst, you need a valve seal job replacement, which is a very minor job.

shdoug

I can't speak for the ease of a DIY valve job, but I think Dave has some stuff on his website about it. http://www.davebarnhart.com/mb300e/default.htm

I do know that these cars have issues with platinum spark plugs. The standard plugs are better for some reason.

jlink38

How old? I built up a 1982 CJ-7 a few years back, never touched the engine and it never burned a drop of oil. I changed the oil every 5,000 miles and it was always full when I dropped the old oil.