I have a 93 Grand Cherokee with a 5.2 I am having an issue with it after it gets warmed up 10 mins down the road with it smoking and when I give it gas it revs up but when I take my foot off the gas (ie stop light) the rpm drops way down, some time stalling, then on its own picks back up to where it should be then back down repeating a few time till it stalls out or levels out at normal. The smoke is clearly inside the engine because if I open the oil fill spot there is smoke inside. Also the temp will run fine for a bit but then begins to climb.
05-18-2012 11:50 PM
Do a compresion test. If that checks out good at least you know its not the rings.
05-19-2012 05:31 AM
I'm confused. Is the exhaust smoking or are you seeing the oil vapor in the heads?
Check for a blown plenum gasket, compression and leak down test, and start checking sensors.