Amazon has the grommet and valve

 

20,000kms ago according to the maintenance records. NGK wires. I'll have to pull the plugs to see if they are fouled from the previous plenum leak

 

so I finally pulled the plugs are they are white. Meaning running too hot or lean... So I am going to replace with autolite 3923's, do a seafoam treatment and run some cat cleaner through it and see what that does. I'll put some 91 octane in as well. I'm hoping this will help? Pretty much at the end of my rope on this thing. I bought it to use as a tow vehicle for the summer and it's a dog with my ski boat on the back. Nothing like my 2001 rt back in the day.

 

How is your fuel pressure?

 

not sure. once i do all this ill see where we're at.

 

So some interesting observations yesterday. I decided just to swap in the autolite 3923's for the 5224's first. When checking the old spark plugs I noticed the front 2 cylinders on either side of the motor look white and ashy while the rear 2 look like normal wear. I fired her up after and cold idle seemed a little rougher but seems to have more power while driving. I went to the gas station and put in 91 octane as I've been using 87 since I bought it. When I opened the cap a bunch of air escaped from the filler opening. It was quite loud and surprised me. So that is another issue. It seemed to accelerate a little better but it still has a rough idle that seems to surge in a rhythm. Also I've noticed that once it shifts to second gear, even if I punch it, it won't kick down to 1st. I am not sure if that is normal.

So to summarize:

1. While switching to autolite 3923's for the 5224's I noticed the front 2 cylinders on either side of the motor look white and ashy while the rear 2 look like normal wear. (lean condition?)
2. When I opened the cap a bunch of air escaped from the filler opening (plugged tank vent or other evap issue?)
3. once it shifts to second gear, even if I punch it, it won't kick down to 1st
4. rough surging idle ( vaccuum leak, )
5. still seems low on power compared to my old 2001 RT (cat plugged from old plenum leak?)

Work that I've done in the last month or so:

1. Intake and plenum gaskets
2. thermostat
3. MAP sensor (aftermarket)
4. grommet and pcv valve (aftermarket, I think I started seeing a little oil residue in the intake after this)
5. autolite 3923

I'm going to run a cat clean through the tank, do a top end clean with seafoam and see that that does. Any ideas or suggestions are welcome. I am having to tow my boat on the 1st for a bout 110kms through many long hills so I want as much power as I can get before then.

 

Surging is a vacuum leak.

Pressurized gas tank is normal. The fuel system is closed, due to emissions regulations. If there was a VACUUM on the fuel system, THAT would be an issue.

 

ok, it seemed very forceful and loud, I don't get that on my x5 at all.

As far a vacuum leak, where are normal places to look on this motor? I sprayed throttle body cleaner all over the place and can't seem to get the idle to change.

 

What motor is in it? For the most part, anywhere there is a gasket you might get a vacuum leak... If you have the 5.9, it has a two-piece intake, and is absolutely famous for the plenum gasket to fail.

 

its for 5.9 and the plenum gasket was just done. Could a failed pcv and a Chinese pcv cause this? Also what about the kicking down to first and the front 2 plugs on each side looking lean?