Tanner Womack

hey there! I’m new to this whole forum thing, but I had a question, I took the whole air box assembly off and decided to take a look down into my throttle body with the flap open and it was extremely black and grimy in there, is this a normal thing or should it be cleaner?

1997 chevy Suburban 5.7l V8 Vortec Engine btw

oilcanhenry

Not really, unless the motors is running bad. Get a can of spray Carb Cleaner (make sure its safe for the CAT) or Sea-Foam and let her rip. Its probably caused by the cheap gasoline they sell nowadays, that doesn't clean up deposits.

That and the motor oil PCV system allowing the oil to get in there. Its more common, in older motors with bad valve seals and worn out pistons and rings.

tech2

+1
its from egr and pvc gases. perform a throttle body clean with throttle body cleaner and a toothbrush. Its routine maintenance.

73shark

Tanner: Welcome to the forum.
What you're seeing is called by a phenomenon called reversion where some exhaust gas enters the intake during valve overlap. As the others have pointed out, cleaning it will be of some benefit.