Decided to take an official look down the throttle body today. Just to make me feel a little better, please say it is not blown!

But really, all that oil in the intake manifold is normal, right?

There's no way it could be blown with 196xxx miles on the engine, right?

I only get 9-10 mpg because i'm a leadfoot, right?

Theres no way the rough idle is caused by this, right?

Well... here's some pics.

 

actually you took a picture of the wrong thing.
go take a picture of the V8 emblem on the door.
if it says Magnum, then the plenum is leaking. LOL.

its hard to tell from your pictures. the pcv dumps in oil vapor, so its going to look like **** whether its leaking or not. the tell-tale sign is a puddle of liquid oil at the rear. i don't think you can see the rear w/o removal of TB.

given the popularity of the hughes plate, another test you can do is stick a long magnet down to the plate. if it sticks (steel), you need a aluminum plate. if it doesn't stick (aluminum), then you've already got a plate, and worst case, you just need a gasket replacement.

edit - i also don't believe the plenum is a direct cause of poor mpg. it might foul plugs and o2 sensors and stop up cats, but running lean with from the vac leak doesn't use more gas.

 

So this is normal for someone with a plenum that isnt blown? I thought that any oil deposits/residue was a sign of a blown plenum...

I will take the whole throttle body off tomorrow, I guess.

 

Get yourself a vacuum/pressure gauge and do the test called out in the TSB.

That looks like a reasonable amount of baked oil for an engine that's got nearly 200k miles behind it. Also, replace the PCV valve unless the one you've got is very new.

Rough idle can be caused by many things. If these things have not been addressed, you've probably got a lot of slop in a timing chain that's about ready to fly apart, a wobbly rotor in the distributor, old tired sensors (particularly the oxygen sensor) everywhere else... you might want to start doing diagnostics rather than just throwing money at the problem hoping you hit the right part along the way.

 

PCV valve was replaced along with the spark plugs and wires.

By a vacuum guage do you mean this ? http://shop.advanceautoparts.com/web..._T|GRP2018____

Would advance auto let me use this on one of their tool loan outs?

I plan on doing the rotor this weekend, I will follow the DIY for it. What is the easiest way to tell if it needs to be replaced?

As for the timing chain, I haven't look at that. Is there a DIY or something that would help me?

The o2 sensors I'm pretty sure are fine, just had the exhaust replaced ( cat and muffler) and i'm pretty sure they would have noticed a bad o2 sensor. Nevertheless, I will also check those tomorrow.

 

you could dump some seafoam in there to clean some of that up and make a smoke show lol make sure the enigine is warm though it will clean up the heads pretty good too

 

No, and I don't see one in a quick scan of the Advance web site. What I'm talking about is one of these handy dandies.

I don't know -- I don't shop there. Maybe someone else knows.

I thought I'd seen one but it's not jumping out at me just now. It's relatively straightforward and the instructions can be found in the Haynes manual.

Good luck finding the culprit(s)!

 

If I were you, I would take off the TB and give it a good cleaning with any kind of TB cleaner. I would replace the IAC along with the TBS (about $60 for both); and if feeling frisky, I would take off the intake manifold and give it a good cleaning + change the gasket.

Yeah, right! Thay could care less about your O2 sensors. Plus, there is no way for a muffler shop to notice a bad O2 seonsor, unless you have a CEL on.

9-10MPG, however, is pretty low. I get that with the v-10...

 

Well,

I changed my plenum at 48K on my 2001. The plenum plate was so clean I could eat off it. Seriously. Looking at that I would say your plenum is blown, but not that bad. It will just get worse though.

The guy brought it in for service religiously. So the PCV was replaced regularly. Also, My lifter galley, and valvesprings looked pristine. Even someone here thought i put brand new heads on.

I got a 2001 made in saltillo Mexico...It seems like they can assemble a great truck.

 

198K miles...do you really need to ask?