abakalen

iTrader: (1)

I was lucky it didn't go into the cylinders...

Yesterday I was changing spark plugs on my 2k2 maxima @ 110K, so when i took off the upper intake manifold, i thought i've heard something, and then i shook it and the screw came out, i couldn't believe it...
I looked on the throttle both screws were in place, so then i took out the power valve, and there it is one screw was missing, it must have been loose there for some time because the screw was kinda rounded up from being beaten up inside the intake manifold.

Another thing was kinda strange that top three runners were very clean, but three bottom runners were pretty much gummed up, and the same with spark plugs on one bank all three spark were clean and in good condition, but on the other bank the sparks were carbon fouled.
Looking further into this i found a hole in y-pipe (stock), apparently the bracket that bolts it up to the block broken/rusted off creating 1/2 x 1/4" hole. I got it welded back on. Hopefully this will fix it.

I couldn't take the pre-cats off, but i don't think they're clogged, with y-pipe off, i started up the car (oh man, was that noisy) and could rev up to the redline with no problems, also the main cat didn't seem clogged, i took it off and could see the light through...

Anyway, i don't know if this common to have the screws missing from butterfly valve, i didn't see much here on the forums about it, but Nissan quality is sure not what it used to be...

teksurv

For the 2.5 motors in the Altima, Sentra, etc. yes it is common. I've not heard much mention in the 3.5's though I haven't searched.

spiromax

The QR25DE Sentra owners over at b15sentra.net have been putting locktite on their butterfly screws to keep this from happening to them. It's not unbelievable to assume that VQ35DE owners might have the same problem.