Crank & crank pulley question- car problems - need help
 

The intermittent metal clacking noise coming from the left mid/rear side of my motor has yet to be figured out. The car is a 1999 auto max with only 45K original. It just started doing this about 4 days ago. I tried to pull codes several times and am only getting 0505. It appears (through top view) that the crank pulley is slightly less linear as far as circular rotation than the others (slightly wobbly). I as well as 2 mechanics and 2 very reasonably skilled car guys have tried to narrow down the problem but can't without taking things apart. We thought that possibly the rubber part on the crank pulley (damper or whatever) has cracked, that the pulley has come loose, or that there is an automatic tensioner problem. This would seem logical given the age of the vehicle. The other scenario is that there is a problem with the crank bearings or something generally more serious. This would seem hard to believe given the car is an automatic w/ only 45k. At any rate, I called nissan to see if the crank pulley is commonly or at-least occasionally due to fail when old. They said that they've never heard of a crank pulley needing to be replaced and that it is probably something with the crank (walking). With your experience, is this true, or as I think may be, that they are full of crap. Please help me out here because I'm afraid to keep driving it like this. :gotme:

Is it that difficult of an issue to tackle? Or is everyone too busy responding to lame "hey should I get a supercharger" posts j/k.

Are you sure the crank pulley is wobbly? I would take a laser level (on a tripod or other stand NOT on the vehicle) and sight it across the pulley. If it really is walking, then you will see it break the beam.

As far as the noise... This is a really wild guess. But power steering pump. It would be approximately in the right location for the noises. Get a turkey baster, suck out all the old fluid from the resevoir, replace it with new fluid. Turn wheels lock to lock, left to right, top off fluid again.

If that doesn't fix the problem, it's either 1)something else. 2) more serious.

Can you describe the clacking noises or what RPM it happens at? cause I;m not feeling the Power Steering guess. Just a shot in the dark and it only costs $3 to change the fluid.

sounds like metal on metal and can be heard (with s***hescope) through the valve cover, exhaust manifold, but not oil pan. Almost like the noise a rock would make if it was bounced off of a dull sheet of metal. It is not too loud, but not soft either. Happens repeatedly and intermittently. Will happen more after revving up and letting down. It just seems impossible to narrow down since it resonates through everything.

You gonna have to open that front valve cover at some point. There's a s*** load of moving parts in there and the area you describe could easily indicate an exhaust valve/cam clearance issue. Not trying to be a pessimest, but tavarish had a similar question a while back, and it turned out not good. See "Last straw for the VQ30DE" currently on page 6. The sooner you diagnose it the better your chances of a good outcome.

Are you leaking coolant?