morpheus

Blue smoke = Burning oil Black smoke = Unburned fuel White smoke = Burning coolant Have you pulled out your spark plugs at all? I'd guess most likely head gasket if there is no external leaks. With loosing that much coolant, you should be able to tell by looking at the tips of the spark plugs. The cylinder(s) that are causing the problem will most likely have white tipped plugs. If you can get your hands on a cooling system pressure tester and a borescope you can pull the plugs, put the system under pressure. Wait 2-3 hours and then look into each cylinder with the scope. You will most likely find a puddle of coolant on the top of the pistons of the cylinders that are leaking. The black smoke you are getting is probably when the engine is burning off the coolant, it can't burn the fuel.

They're really bad for u-joints. probably front and rear need replacing.

I don't recall off the top of my head the manual vs. auto, but I think someone here had a manual one they said they took apart and it didn't have them. We only had that one, and it was a couple of years ago now. nothing since.

I'm a service manager for North End Nissan ( www.northendnissan.ca ) I've only ever had 1 R50 with 1 power valve screw missing, and we replaced the entire power valve manifold section under warranty.

only if you're pre- 90. 90-96 will all be quads.

It seems like there's a lot of people asking a lot of questions here. Let me set a couple things straight for everyone. 1) The power valve screw issue was NOT a large problem with the 3.5l. Did it happen on some? yes, most, no. In all the pathfinders's I've serviced, I only had 1 of these happen to them. 2) The power valve screw issue with 2.5l sentra's and altima's WAS a problem, and a recall was issued on it. 3) Can you take your intake apart and secure them for peace of mind, of course you can, it's actually a pretty simple process (3 hours should be plenty of time) 4) If you are going to do this repair yourself, MAKE SURE that you only remove 1 screw at a time and thread lock it. The valves are percicely aligned, there is a special jig that is used to align the ones on the altima/sentra's. 5) The power valves and screws are NOT seperate from the lower intake manifold collector. Hence it makes it a power train item and is covered under the powertrain warranty. The person with the 04 should still be under warranty, unless his 04 was registered in early 03 6) If a screw happens to fall out, chances are that it will simply embed it's self into the catalytic converter, where is may/may not stay. If it comes free, it can be sucked back into the engine and score the piston walls. If it simply goes in and out, it's unlikely there would be any damage, but if you are doing this repair and find a screw missing, pull your exhaust manifold off and remove the screw. Yes I know that's a tonne more work, but it's worth it. 7) any locktite should do, but I'd suggest red locktite. There's no reason you would ever need to remove the screws for servicing. 8) You should be able to re-use all the gaskets, unless any become damaged in the process, and in a pinch a dab of silicone gasket would get it back together. 9) Only Pathfinder's and QX4's with the 3.5 have the power valves. All other 3.5's (altima/maxima/etc) have a different intake design.

The 300zx is a quad cam engine. I'm certain that it would not work.

I installed LT245/75R17 BFG Tk tires on my 98 with no issues at all, all factory suspension. They are about 31.6" tall tires.