Smoking, Oil Problems.

[Mightiestmike]

1991 MGM, 5.0L V8 EFI


Ok so the Oil light comes on, but when you put ur foot down on Gas it goes away. So what i am thinking is that we have the wrong Oil Weight in there. we have 10w30 in there right now, there also appears to be an oil leak as the bottom of the car is Covered with oil. but we just had it serviced and u'd think they'd have noticed that. I found the spot that I suspect to be leaking, (some loose hose) I'll post Photo's of my problems l8r, (batteries died in my camera.)

The reason I think it is wrong Oil weight is cause I read somewhere that the engines in this car have very narrow channels and pathways for the oil to go through. so the thicker oil could be a problem?
Cause I figure that when I accelerate the pressure increases and forces the oil through, and then the light goes off. (am I right? Do I need to Switch to a thinner Oil? or Synthetic?)

Also when I stop and the car is Idling I can see smoke comming from the hood, I'm pretty sure it is an exhaust issue but I'm not sure... and when I take the dipstick out to check oil, smoke comes outta there a little. (smoke is comming mostly from left side)

Also, anyone with this Model can confirm this for me....
The Dipstick has got the Yellow handle and is on the right of the engine when standing infront of the car..... I also found what appears to be another dipstick!? on the left, but with a black handle... and when I take it out is says stuff about oil on it...

[jimmytroanoke]

Oil light could be a bad sending unit. Check that by installing a gage in its place. Wrong weight oil wouldnpt cause your problem(light) as sending unit is generally earlier in the circuit than the tight passages. Your oil pump could be going or your main bearings could be worn. Any knocking or tapping going on? If your leak is in an oil cooler line, better get it taken care of. You could be losing pressure there but if it were bad enough to reduce pressure, it would pump you dry in short order.
the Black dipstick is usually Auto tranny fluid.

[Mightiestmike]

Ya it knocks/taps
and I'll look into what line that leak is in.

[fredjacksonsan]

If smoke is coming out of your oil dipstick hole, you might have a head gasket problem, which is allowing the exhaust to enter the engine. Is your oil discolored, or does it get dark quickly?

As far as the weight of oil to use, use whatever is recommended by the manufacturer. If too thick, it will take longer to move around in the engine and may starve some parts. If too thin, not enough oil to properly lubricate.

As far as the check engine light, does it come on at idle a) in gear b) in neutral/park or c) both? Does it go away once you are driving normally? Does it come on at any other time?

[kike058]

If the oil light on comming on on idle and off on acceleration, you must have worn bearings (Crank and/or Cam) and bad oil pump.

Wrong oil grade does not change the perssure that bad.

On the smoke comming from the oil check pipe, check you PCV valve, check cilinder compression looks like you must have worn or overheated piston rings.

If the cilinders are on good condition you must have around 125 PSI copression (80 - 85 PSI still good)