2002 QX4 back on the road after engine removal for sucked power valves (long)

[QX42002gold]

I just wanted to follow up with everyone after getting my QX4 back on the road. First...read the sticky post on putting threadlock on the power valve screws!!! If I had known about this potential problem before my engine sucked down three of them, I wouldn't be writing this today.In short, this project sucked big time, trust me when I tell you, you don't want to do it or worse...pay someone else to. Upwards of 40 hours work all told, of course I've never worked on this engine before but I'd be willing to bet the bill would easily be in the thousands. Anyway, good news is no major engine damage but I had to tear it all down to be sure since the engine did eat six of the little brass screws. Once I had the intake, both heads and the oil pan off I was able to inspect the entire engine top to bottom and must say for 96,000 miles internal wear is at a minimum: Mains, pistons, rings, cylinder walls, cams, valve seats, seals, timing chain and tensioners all looked suprizingly good. I have been running Moble 1 since the day I bought it @ 54k and the first owner had documented dealer oil changes every 3k since new.. a testiment to routine maintainance.The only damage I had was some marks on the heads right around the intake and exhaust valves where the power valve screws beat themselves into dust. I was able to polish these out with some fine emery cloth. I found all three power valves from the intake so luckily the combustion chamber never saw any of the silver-dollar sized disks. One was laying on an ajacent valve and the other two were stuck in the web that seperates the two intake valves in the #1 cylinder. This is where all the noise was coming from, everytime the intake opened for that cylinder the two pucks would clank together like shuffling a deck of cards (brass cards).So, to anyone who owns one of these fine vehicles, take the time to have the intake cracked open and make sure your power valves (secondaries) are nice and tight! I'll also add when I went to get new screws for the valves, the new ones have a flat washer which helps to keep them tight, I would recommend you just buy all 12 and use locktight too just to be sure. I also learned from the guys at the parts counter that this was a recall on the 2.5 sentra motors, thus the reason for the new screws with a washer.

Anyway, the Q is back on the road with all new gaskets, belts, hoses (15 cooling systems hoses!) plugs, intake and exhaust valve seals, water pump, thermostats (yes there are two) and it's all nice and clean and running like a champ. Drove it 150 miles today with zero problems.