My 97 Z28 has a pretty dirty Intake manifold because it was sucking oil from the passenger side valve cover port that goes to the throttle body.
I replaced the 90 elbow with a piece that has a filter in it so it can't pull up the oil.
What would be the best and cheapest way of cleaning the intake manifold?
I was going to use some SeaFoam in my I.V bottle that I have but I think it's too dirty for that.
http://www.seafoamsales.com/
I was also thinking of using a couple of cans of carb/intake cleaner.
I don't want to take the intake off but the car runs great no trouble codes just very bad gas millage.
Let me know what you think.
Thanks,

 

seafoam it through the brake booster line, do a search to find out exactly how. it that doesn't work id just take the intake manifold off and throughly clean it using the deep creep spray. just my .02. good luck

 

I'm going to give the seafoam a try tomorrow with my I.V bottle I have it plugs into the brake booster line.
If that does not work I guess I will just take the intake manifold off and take it to a machine shop and have it cleaned.
Thanks,