from what ive read oil in the intake manifold means there is a leak in the plenum? am i right? i go to school for automotive and took the throttle body of to check the gasket and noticed that the gasket had oil on it and so did the area around the butterfly's. so i took a flashlight and looked down and sure enough the was a little puddle and the walls where wet. Will a plenum leak cause the engine to seize or anything bad like that or can it be fixed when ever i can get to it. Ive seen guys on the forum buy a all ne plate and everything and i have looked at them before and want to put a hughes kit in but i also dont want to spend 300 or so dollars into it, but i will if i have to, could i just throw new gaskets in or is there more to it?

 

Oil in the bottom of the intake plenum pan most likely is the gasket leaking, but a bad PCV valve can suck up oil into the intake.

The only negative side effect of a bad plenum gasket is poor MPG and HP and burning oil and possibly bad pinging when under load.

Yes you could just change the gaskets and call it a day. Fel Pro has a good gasket that has built in O-Ring style seal that will help with the blow out.

The hughes kit is only $110 or so.
http://www.hughesengines.com/Index/p...3&partid=26190

 

haha i had looked at that before and some reason 300 dollars stuck in my head. Where exactly is the PVC valve located? I have a loping idle with a load and at idle, and the have a very strong feeling that the plenum has never been touched on this truck, to the best of my knowledge. I get about 11-12 city and am lucky to get over 15 on the highway, i know that thats somewhere close to what they got when new. Ill have to check the PVC valve and mybe i wont have to spend to much. Thanks for the reply

 

The PCV is on the pass. side valve cover to the rear. Little plastic thing with hose. They are inexpensive and easy to replace. Just pops out.

 

im just goin to replace the PCV valve just because it is only 2.99 at the advanced by my house. How hard of a job is a plenum fix, for a average level person, and how long? one of the post said it would be a weekend project, ive watched videos on youtube and it didnt seem hard just taking off a lot of parts. When it comes to the intake and plenum bolts, are they the same length or will i have to mark where each of them go? just tryin to plot things out before i go wrenchin away

 

It is not to bad but like you said a lot does have to be removed. It is worth it in the long run. For your first time it will take longer since you don't know all that you need to remove. Make sure you have the time a weekend is good just in case you can't finish right away. Make sure you have all the gaskets and fluids. Do an oil change since dust and particles from the gasket and coolant will get in. Best to drain all coolant and do a flush once done. Get both gaskets for the intake the plenum and the intake to heads. Might as well change the thermostat and gasket and bypass hose which is a pain if it fails on you. Change all hoses that are soft.

You will need to remove the fuel injectors and AC compressor. You can move the AC Comp. to the side and tie the fuel rail with the injectors to the hood. So this way you don't have to crack open the lines on both systems. Just don't hit the injectors or else you can snap them easy.

The service manual has all the details on the R&R on it. Yes the bolts the plenum are all the same size. Make sure you torque down all bolts to the proper torque rating and in the sequence, the manual has it all listed.

 

i used one of the information systems that we have at school, i think it was Alldata, i printed everything they had about the plenum. i replaced the thermostat a little over a year ago, should i replace it anyway? and should i get a 180 degree thermostat?

 

The injectors don't individually need removed, start the truck, pull the fuel pump relay and let it die. Then you can disconnect the fuel rails at the line.

 

changed the PVC and it looked like there had been oil comin up through the valve cover. i changed the valve and runs and idles a lot better, still fluctuates at idle but settles down after a few seconds and is smoother when put into gear. Still am plannin on gettin the hughes kit but have to wait for my sister to find a new car (the tranny in her 1993 dodge shadow just died) we only have 2 cars at the house and our mechanic ( who is a real close family friend) has lent my dad a car will be wanting it back soon so i have to put the work on my truck off until everything gets back to normal at the house