Hey guys. Searched and found some great info on the dreaded plenum gasket failure. I am looking to do mine very soon. I am experience some spark knock and I am burning premium or booster for the time being to mitigate that as much as I can until I am ready to do the work. I am acquiring the parts and pieces as we speak. Is the Hughes plenum kit the way to go? I planed on doing a cap and rotor while the top is off, as well as the O2 sensor as mentioned on these forums. I also really like the Sea Foam idea to clean the injectors and such. Anything else you guys can recommend while I have the upper half off?

She's a 99' 360 with around 70k on her. Yes, she sat a lot and now she actually has to work for a living.

 

Hughes kit is good. You can also get the intake gaskets/bolts from them, for a total of around 140.00.... (everything you need for the plenum repair.)

I didn't like the hughes gasket, so, picked up felpro plenum gasket. (around 20 bucks)

Do the cap and rotor while the intake is off, wires too if they are older. Plugs certainly wouldn't hurt.

Might wanna do the seafoam thru the intake BEFORE you do the repair.....

 

I'll second that. I just replaced mine on Sunday with the engine intact, and it was a challenge that left me literally bruised and bleeding. If it weren't for the numbered plug wires I've got I'd probably have spent an additional hour or more at it. From here on out, I am treating the cap and rotor like a rear main seal or rear freeze plug -- if I can get at them easily and they're not nearly new, they get replaced.

 

Bypass hose and the best Tstat you can find. Test it first. And cut the tab of the tstat housing. And if your not going to go nut's cleaning the inside of the intake, leave the fuel rails attached or get new injector orings also. Don't remove the TV cable from the bracket either, just disconnect the throttle cable first, then remove the bracket from the TB with the TV cable attached.

Edit btw, it probably wouldn't hurt to install a new oil pressure sending unit while the intake is off. Along with cap, rotor and wires as already mentioned.

 

Can you guys recommend and good wires, cap and rotor?

Zman: What is the bypass hose? What tab on the t-stat housing do you speak of?

Thanks to all!!!

 

Remove the thermostat housing and you'll see said tab. Take note, though, that the t-stat housing has a very, very slight bend toward the front of the truck. Ensure that it's reinstalled that way when everything is reassembled.

 

Bypass hose is a 90 degree hose that you will see once you remove the accessory bracket off the front of the motor. Goes from the WP to intake.

 

Mine had "FRONT" Stamped into the.... erm.... front of it.