Posted by HemiMech on Wednesday, February 28, 2007 at 14:44:01 :
In Reply to: Re: 2500 needs one also posted by 68427vette on Wednesday, February 28, 2007 at 12:33:39 :
On the 5.9L If oil consumption is high or your getting excessive spark knock in warm weather its likely the intake manifold belly pan gasket has dried out and sucked inward. This is a plate that bolts to the bottom of the intake to close off the plenum. When the gasket gets old the engine is getting extra air from the crankcase...basicly a vaccum leak that can change due to the amount of oil that is being pulled across. Thus the high Idle. Fuel pump/filter failures are usually loss of power at high end or don't work at all. Also possible is carbon deposits on the Idle Air Control IAC motor that bolt to the side of the throttle body with a couple of screws. Remove it, clean the pindle with a carb cleaner and a brush.
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