Mechanics

HOW DO I FIX A OIL LEAK THAT I CANT FIND WHERE ITS COMING FROM.WHEN THE OIL LEAK BEGAN THERE WAS ALOT OF BLACK SMOKE COMING FROM THE EXHAUST

1991 Nissan 300ZX

The car when started after I clean the spark plugs runs fine for bout half and hour then it starts to sound like it has a miss in the engine then the black smoke comes from the exhaust. What can be the problem with the engine. I bought a new engine seal kit for it and was wondering if changing the seals would fix the problem.
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PARKS55
December 8, 2011.



Black smoke usually indicates a rich fuel mixture. As far as the oil leak, you can get a dye to add to the oil. Drive the vehicle and then check for the leak with a black light. The dye will glow.

Easy enough to see a leak off a manifold, try placing cardboard under the engine area so the drippings will probably show. The black light system does work on small crack leaks like on a transmission case or a cracked engine block, good luck.

Tiny
Dkblue300ZX
Jan 23, 2012.