1996 Chevy Astro black exhaust upon acceleration

BARON88

MEMBER
1996 CHEVROLET ASTRO
6 CYL
AWD
AUTOMATIC
138,000 MILES

I'm considering buying a '96 Chevy Astro AWD from the estate of a friend that recently passed. The van is in the shop to be checked out before I decide to buy it. The main issue with it that concerns me is the fact that it emits black smoke during acceleration. My mechanic tells me there are 4 O2 sensors that need to be replaced. I know black smoke usually means a motor is "running rich" but I wonder if this is the case here? Any advice would be great? Thanks, Trent

Tuesday, August 12th, 2008 AT 12:54 PM

1 Reply

JETSA

MEMBER
117 POSTS

If the vehicle has low mileage, there is the possibility that the truck wasnt driven much and probably never "opened up" on the highway (really accelerated hard). Lack of occasionally doing this will cause huge amounts of carbon to accumulate and when someone finally does "open it up", the results are huge amounts of black smoke coming from the exhaust. This is most common on the vehicles that "little old ladies who only drove to church and back" owned.

The mechanic may be right. These carbon deposits will settle on the oxygen sensors and GM doesnt recommend cleaning of oxygen sensors, only replacing.

Normally after "blowing it out" a few times, the black smoke will subside and eventually stop.

Was this

answer

helpful?

Yes

No

Wednesday, August 13th, 2008 AT 6:27 AM