My crank pulley looks like it's spinning SLIGHTLY off its axis, and I can definitely hear a little rattling/scraping noise coming from it. I see the jiggling when I view it face-on, but from above it looks normal. The belts are tight, none of the other accessory pulleys are moving strangely, and I don't feel any play in the crank pulley when I remove the belts.

My coworker says I might have spun a crank bearing. Anyone wanna tell me different?

 

Your coworker has no clue what he's talking about.

The crank pully has a rubber isolation sleve that runs around it. Check to see if it's starting to let go, you'll see the rubber starting to crack and break down. Replace it if thats the case. Remove the right front inner splash shield to get a good look at it.

 

Mine went when my Wife had it up in DC for the weekend (300 miles away, D'OH!). Had to rent a auto-dolly from UHaul, drive my truck up, tow it home, and then find a used crank pulley here on the forum... no fun. =( Plus I got a speeding ticket for doing 75 in a 65mph while towing the car home, which just added insult to injury... =(

Definitely look into getting a stock crank pulley to replace it or possibly look into getting a Motorstorm UD Pulley... =/

 

I checked that.... The rubber ring looks okay from what I can tell, and it's pretty uniform all the way around.

The thing is, even the bolt is moving around (the same way as the pulley). I would think that if it were just the rubber letting go, the bolt would look like it's just spinning in place, no?

 

I had the same problem with my old jetta. I never fixed it(car was a piece of crap). What i suggest you to do, is change the pulley(udp), put a new rubber ring and see if it works. I doubt the crank is off, cause the motor wouldn't run well. Other then that, i'm clueless

 

In what way would the motor run poorly if there were something wrong with the crank? It doesn't feel like it quite pulls as hard as it used to and my mileage is definitely a little on the low side, but those could be due to my driving and the big sub I put in the trunk recently. My engine isn't vibrating uncontrollably or sounding particularly strange at any RPM...

 

Here's another thought.

I was talking some more with my coworker, and he's thinking that the problem might be the water pump. I've had a coolant leak for some time now that is really hard to trace, but from what I can tell the water pump is the most likely source. Maybe the bearings have gone bad and it's shaking on the timing chain, causing the crank pulley to oscillate?

 

No help...?

 

thats a very bold question.

Well, if the bolt on the end and the pulley are wobbling together, and that rubber is still solid, I would be wary that maybe the crank bearing on that side is going bad. Never heard of that before on a maxima, but it's usually caused something unbalanced. Crank walk can result. Engine would definitely run bad. If it's a completely spun outer bearing, it's alot less worse than a spun con rod bearing. I'd still be pretty apprehensive about what you just described.

 

How do you figure? A spun outer crank bearing would definitely give visual symptoms like that. The bearing could still be intact, but on it's way out.

 

Yeah, I was worried that that would come across wrong. I was asking about specific warning signs (vibration, thrashy sound at high RPMs, etc.) to look out for. "Poor running" is a pretty general term.

 

The crank will not move around if one bearing spins out of place. You'll simply loose oil pressure.

It the crank shaft was moving, even the smallest amount do to play in any bearings, the car would **** oil out of the crank shaft seal.
And again, you'd have absolutely no oil pressure with a situation like that.

 

It does look like I'm losing oil from that seal, but it's only a few drips here and there... nothing huge.

Is the water pump theory looking plausible then?

 

free bump, in interested in teh results.

 

Thanks for the bump, s0ber.

For you and anyone else who cares, it looks like the water pump was indeed the cause. I just finished replacing it and based on a cursory examination, the old one looked like its shaft was bent by about ~2 degrees. The crank pulley looks MUCH better now, except for some minor vibration. It does have radial cracks in the rubber ring, which is not unexpected above 125k miles. I guess I'll be replacing that later.

But yeah.... chalk one up for weird stories.

 

yeah ive actually got a similar problem atm... unlike you though i can however feel the engine idling funny, see some lateral movement in the crank pulley from above, and hear a squeak coming from somewhere. i'm going to investigate this further this week, i havn't been driving the car much and it just started. grrr.