Serious engine problem?

[Anonymous]

I changed the spark plugs on my 170
: with 160,000 miles on it and all of
: the old spark plugs had wet oil
: around the threads and the ends were
: black and burnt. I changed the oil
: pan gasket and found really hard
: pieces of rubber or something in the
: bottom of the pan. Also I've noticed
: really dark exaust, almost
: oily.Could it be my Piston rings?
: Thanks for any advice.

 

[80broncoman]

I think most likley the oil on the threads of the plugs are from a leaking valve cover gasket in the past. (I alway put 1 drop of oil of plug threads and they are never hard to remove)
The hard pieces of rubber or somthing are maybe nylon teeth from a cam gear. Yes a engine will run with out the nylon teeth as the nylon is just a cover for the real teeth. The cam timing will be a little slow and once you lose enough of the nylon there will be enough slack for the chain to jump a tooth or two, or three then it will really run bad.

 

[Asa]

best way to figure out if you've got a problem with rings is a compression check
if that turns out good, i'd look elsewhere for your problems

dark exhaust could just be from it running rich (which would cause black, burnt looking plugs)
and i second the oil on the threads comment

 

[rickwrench]

Black smoke is gas. Black plugs show a rich condition. If it was a busted ring it would be only one cylinder. Are the center plugs a bit darker than the end plugs?
Crap like you described in the oil pan could be a number of things:
Dried out broken bits of oil pan gasket, or valve cover gasket (which might explain the oil on the plug threads). Might be broken up valve stem seals, too. A dried out, broken up valve cover breather grommet.
Are you using a lot of oil?
Rick(wrench)

 

[mustang6]

My money is on valve stem seal material for the hard rubber bits. Pull the valve cover and look to be sure.

 

[Asa]

how would the seals get to the pan from the top of the engine?

 

[mustang6]

how would the seals get to the pan from the top of the engine?

Right down the oil drain holes- they go from the corners of the head right down to the pan (same places the oil runs so fast to the pan when you pour a quart in the valve cover). Only pieces smaller than a certain size will fit down the drains though. So what you commonly see is smaller bits of the valve stem seals in the pan, larger bits collected at the tops of the drains.

 

[BIGREDRASA]

The stem seal pieces can also block the oil return holes, raising the level of the oil, to the point that it leaks out under the valve cover gasket. The oil return holes need to be cleaned, to remove any crud that may have built up in the passages.

 

[Anonymous]

Thanks for all the great advice! Can I check the compression myself or do I have to go to a mechanic?

 

[BIGREDRASA]

Buy yourself a Chilton's or other book, and a compression gauge. Read the directions. Save some bucks and learn. Nothing beats doing it yourself.

 

[Anonymous]

DAVO, I'm also betting the pieces are from your valve stem seals. I just finished doing this seal replacement on mine this past weekend. My old seals where like little hard pieces of plastic, I guess the rubber seals get hard over time as well as exposed to the heat. I had some of the same symptoms as you do oiled fouled plugs, and oil on the plug threads. I have not driven the car much since the seal replacement, to see if this solved my problems. I also cleaned all the oil passages in the rocker arm assembly and the engine has quieted down considerably. One other observation is when I start the car now there is no initial puff of smoke out of the exhaust. Lowell

 

[BIGREDRASA]

As for replacement of valve stem seals, do a search. It's been covered previously at length. 8)