Hey guys my pining is getting worse.. On my 98 Jeep Grand Cherokee with the 5.9.. Today i couldnt give it any throttle above 2200 rpm without it pinging every second.. thankfully the engine drives under 1800 rpm 95% of the time usually always at 1100 rpm while in the city. Im still getting 12.8 mpg average in the city but i do lose some oil and i cant WOT the engine and have fun anymore without fear of the pinging... So i need to replace my plenum once and for all..

My question is this. Im fairly mechanicly adept as I have already replaced my viscous coupler in my NP249 transfercase, and replaced my timing chain, timing cover gasket, water pump ect on the engine awhile back.. What tools/supplies will I need before i start this project ? I want to have everything I will need ready before hand because I work M-F so this will have to be done on the weekand and hopefully i can do this bymyself and not screw anything up and have it done in 2 days.

When i say tools i mean what size sockets will i need, what kind of torque wrench should I buy, what fuel rail puller do i need to get, what type of gaskets do i need.. Everyone talks about the plenum pan and gasket but no one mentioned what type of gaskets you need between the engine and the manifold itself ? Does the Hueges kit include new intake bolts ? Or do i need to get those as well and which ones will i need ?

I thought about just buying the kit and having a shop do it because im worried ill mess it up, but then shops around here charge like $100 an hour and if it takes 4-5 hours to do plus the kit.. then thats like $700 which to me is way too much.

Thanks

 

The Hughes Kit will come with new bolts for the pan and all the gasket's needed to put it all back together.

I don't remember what all socket's we used, a standard set (metric included) should be able to get it, might need a deep well or two, can't remember at this point.

You need an inch lb and a foot lb torque wrench, you have to torque it in stages starting at low number's so you need a torque wrench that get's pretty low, the hughes kit comes with instructions on how to torque properly.

You should get new intake manifold bolts from your local dealer, it's just better then reusing the old ones, chances are they will have to order them, but they should be able to have them next day, expect to pay around $16 or so.

Probably wouldn't hurt to get some RTV Silicone Gasket Maker.

Not sure on the fuel line puller, we just put something together.

 

Well I am about halfway through my plenum project, just one quick question. How clean should the mating surfaces on the keg and intake actually be? Should it be shiny clean on both of them or just get the bulk of the gasket off?

Also I am still struggling with one of the broken off bolts, it is the very back one on the passenger side. It has about an inch of bolt sticking up and my vise grips just slip on the threads. I PB blastered it every few hours over the weekend, I am going to attempt it again after work. Any tips would be appreciated!

 

Pretty clean, get a flat scraper and scrap the surface clean, don't cut into the metal, just smooth scraping.

As for that broken bolt you could try an easy out or if you have access to a torch you could try heating it up a bit and then try the vise grips, just be careful if you go this route, PB Blaster is flammable and you don't wanna burn down your truck.

 

So some of the black coloring from the gasket won't hurt anything as long as it is all smooth?

 

You want the mating surfaces to be as clean as you can possibly get them. You do NOT want to have to do this job again, because of some leak there. I polish them smooth... but, I have air tools available to take care of it too. Using elbow grease, it is tempting to just get it 'close enough'..... but, I hate redoing work.

 

I guess I am going to get some scrub brushes and razor blades at the dollar tree and do work.

 

If you have an electric drill, pick up a wire wheel for it, with the brass bristles. Wear goggles.....

 

Aye so what about that torque wrench only going down to 20 when your suppose to start off@12?Do I just get close?

 

There's this one. Its a beam style.... which I don't particular care for, but, cheapest I have found so far that goes low enough...... I prefer the clicker type..... but, can't find one of those..... They have a dial type, but, it is more than twice as expensive.