OK so iv read the end all be all plenum thread, and most of the sticky's, but here is my plenum question. I bought a 98 4x4 with a 5.2 the other day with 222,xxx on the clock. it runs fine but i don't think its as strong as it should be. no trans slippage just seems like engine isn't all there. so today i change the plugs, cap rotor and wires. while i was changing the plugs i looked inside the tb, and the intake is dirty, bad dirty, however it doesn't look wet more like just crude. and none of my plugs were oily, in fact they were all white, just burn't like its running lean. so is it the plenum or does it just need a good cleaning with some seafoam.

sorry for the long read

 

Well keep in mind that the pooling typically occurs towards the front of the intake, so looking down the throttle body may not tell the whole story. If you have a good mirror and light you can get a better look, but with 222k on the clock - the 8 ball says it's probably toast.

 

I think you mean the back of the intake, i.e. the firewall side not the radiator side.

 

the truck is running lean. yes i would be doing the gasket set. even if there is no sign of pooling or oil on the plugs your pulling too much air from some place that the TB is not accounting for. and with the miles that are on it. i would be doing it anyway right along with the tune ups

 

And with that kind of mileage on it, timing chain and gears would be a good plan too.

 

thanks for all the replies. i havent dug in to check the timing chain just a tune up. i havent done the magnet test yet but will tomorrow. would the plenum gasket being busted cause a your ac vents to switch around, kinda like a crazy vacuum leak. Also the previous owner put 285's on it with the stock gearing so i know some power loss has gone there.

 

Do a search on "wild vents" for the fix for your vents doing silly things.

 

yea do timing chain...i jsut changed mine at 208,xxx about 500 miles ago, and i could almost pick the chain off the gears it was so loose....VERY simple job to do that, and get the huhges plenum set....just a gasket will not fix it.....and get the manifold cleaned at a machine shop, nd it will do wonders for you.

 

guess i'll be ordering the plenum kit after payday. how long did it take yall to install roundabout.

 

LOLOLOL. that's a trick question.

Mine took several days..... but, that was because of broken bolts, and a faulty gauge on the torches.

If you don't run into any problems, figger on at least a full day. Then, if you get done early, you can smile wider, and pat yourself on the back harder.