engine questions. need some help

[pres_slappy]

I am helping diagnos my future mother-in-laws car. She did not pass emissions testing and after putting it on a scope, she was told the valves have carbon buildup on them and they will need to be replaced to pass emissions at a fee of 900 bucks.

does anyone know what causes the carbon build-up? and a easier cheaper way to fix it then replacing the valves.

i thought it would be from running too rich, not changing oil properly, or too low quality gas.

any thoughts? thanks all

[Danger Dude]

Carbon builds up from incomplete combustion usually from lack of tune ups, clogged injectors or oil getting past the rings.

[timpryor]

run a can of seafoam through it, i have a writeup on it in the
"how to" sectrion it will clear alot of the carbon buildup out

[jimmy_beaner]

how often are you supposed to do tune ups? Also, would seafoam be a smart idea for a 2002? Just to trying to get the engine to where it should be.

[Danger Dude]

Quote: Originally Posted by jimmy_beaner how often are you supposed to do tune ups? Also, would seafoam be a smart idea for a 2002? Just to trying to get the engine to where it should be.

I do a tune up every year. This lets me see how everything is like sparkplugs which I change every year.

Seafoam is great for cleaning out the Intakes after the PCV valve allows oil to get past it and gets the intakes grungy