99 rodeo ghost

my 99 rodeo V6 has a ghost in the system and i cant find it. at start up the rpm's jump to 2,000 and when it warms up it will drop to 500 or lower. idels rough and somtimes dies at start up if its already warm. thought it was water in the gas. its not. thought i was down a cylinder but it makes 98% power. top speed used to be 110MPH but iv lost some it will only do about 95. i live overseas and the cost of auto repair is OUT OF CONTROL and shady so i need to be able to do this myself. if i cant im going to have to park it for almost two years till i come back. pluse this is my daily driver and i have put almost 2,000 miles on it this way. any suggestions? has this happened to anybody else?

It is a bad intake manifold gasket. Very common. I've had to replace mine 2x within 75k miles.

Read up in the FAQ's for more information.

It is a bad intake manifold gasket. Very common. I've had to replace mine 2x within 75k miles.

Read up in the FAQ's for more information.


does that mean a leak in it ? if so then how do u test for it cause mines doing that to if not evenworst

Depending on how bad the leak is you can spray carb cleaner around the intake gasket areas and if the idle changes its broken. It doesnt always do that with a broken gasket though so just because the idle doesnt change doesnt mean for sure its good.

A bad/dirty idle air control valve can also cause high and erratic idle. But broken IMGs seem to be more common.