I've got a 97 dodge ram 1500 with a 5.2 and have been having a idle issue. Everytime after driving and putting the truck in park my rpms will shoot up to about 1200 and I can kind of ease on the gas pedal and make it go down after messing with it for a couple minutes or sometimes it'll go down on its own. And when I put it in drive it still wants to idle high, it's trying to still push the truck forward a bit while I'm stopped. I think it does it a little more in colder weather but it still does it on 60+ degree days. Just trying to figure out how I can find the problem.

 

Probably the throttle body is just dirty, and the IAC can't adjust properly. In any event, its the first thing to start with. Get a TB gasket, actually take the throttle body OFF the truck, (disconnect the battery first...) and clean the snot out of it. IAC mounts to the back, with two little screws, remove that as well, but, be careful with it..... you can wipe off the end of it, but, do not spin it. Then clean the IAC well REALLY... erm... well..... (brake cleaner, or carb cleaner works reasonably well, and if you can get in there with a bottle brush, so much the better.) Once it is clean, have a peek in there, and make sure nothing is broken, or corroded away.... put it back together, and reinstall with the new gasket. Hook the battery back up, turn the ignition On, (not start) count to 10, (don't touch ANYTHING) start the engine. It should figure out idle pretty quick. If it still idles high, you may have a vacuum leak somewhere.....

 

These are all good answers. If your truck pings uphill, fouls the plugs ,mysteriously uses oil, idles 1000 rpms " once warmed up".,these all point to the pesky plenum gasket issue. They basically put a sheet metal pan under the thick aluminum intake manifold. Anyway the gasket blows out, then you suck oil into your intake, spark plugs. Typical symptoms are 3 to 5 mpg worse mileage, the 1,000 rpm warm idle, fouled plugs, disappearing oil usage

 

I actually redid the plenum almost 2 years ago but somehow the gasket that seals the plate to the intake got sort of rolled up and you can see it in the very back. My pcv alve has also been sucking oil into it since I redid it so basically did no good. But I've got a filter for the pcv now. But I'm worried if I weld it that it'll somehow get oil in there again and then I'm screwed as far as taking it apart again

 

What method did you use for the repair?

 

I ordered the kit from plenumrepairplate.com

 

Is the pcv valve bad/sticking? Could also be excessive blow by.