Serpentine belt coming slightly off

[pandemonium]

I'm having a fun time diagnosing the cause to this problem of my drive belt coming off about a 1/4" toward the driver's side of the car. I can walk it back with the engine off and it does it again if I crank it. 2006 RSX, stock K20Z1, 204k miles.

My initial diagnoses showed auto-tensioner positioning was dead center when the engine was off and running. All of the pulleys are tight, with no wobble or misalignment from what I can see.

My first thought was a bad belt, so I replaced it. The original belt had a few cracks, but nothing major. It wasn't that bad, but it did have 140k+ miles on it, so I figured it wouldn't hurt to replace it. I replaced it with a Gates Micro-V K070669 (found at O'Reilly's). It popped off once, so I checked the power steering fluid and flushed out most of it with new. After flushing the fluid, I thought I had solved my problems until 3 days later (about 200 miles worth of driving) it popped slightly off onto the edge of the power steering pulley and frayed the belt. After faithfully limping home, I ordered the Ktuned OEM replacement autotensioner and OEM replacement belt.

I got both in (the new belt had very little slack with the new tensioner, but I finally managed) and it pops off slightly as it did before as soon as it cranks. The autotensioner positioning is just behind (toward the rear) of the marker. I assume that's a little tight, but not overly so.

So, here's where I'm at: I'm thinking maybe it's bad pulley bearings on the power steering pump (or a bad pump altogether; however, it pumps fine while it's running), causing drag on the belt and making it walk over. If I spin the power steering pulley toward the front of the car, there's a good bit of resistance. If I spin it toward the back, there isn't much at all. Interestingly, if I spin it it back, then front, I can hear an extremely slight clicking sound just before the resistance pops in. I'm not sure if that's a sign of anything or if that's normal.

Anyone have any ideas what I'm dealing with? I appreciate any input!

Thanks.

 

[RLGL]

It is out of alignment, one of the pulleys may be moving fore and aft while the engine is running

 

[pandemonium]

It's only ever moving toward the driver's side though. I've spun all of the pulleys manually with the belt off and don't see that kind of play. Granted, the crank pulley is pretty difficult to tell (since I haven't removed the spark plugs to make that spin easier).

 

[pandemonium]

Stupid question: I should be fine to run it from a cold engine without the belt on for a little bit to see if the crank pulley is sliding back and forth, correct?

 

[PottedMeat]

so this belt goes around
-crank pulley
-tensioner
-power steering
-compressor
?

maybe theres some crud between the tensioner/ps/comp body and the engine causing misalignment

 

[pandemonium]

Yeah, with a clockwise rotation.

When I replaced the autotensioner, there was some build up of belt on that pulley, but the new one is sparkling clean. I also cleaned all of the pulley tracks just for giggles, but there wasn't anything built up enough to cause the belt to jump off the tracks. The only pulley that the belt is coming off of is the power steering, and that pulley wheel is pristine with no nicks in it.

Otherwise I'm not sure where crud could be built up. What should I look for?

 

[boomerang]

I think you had a bad tensioner and you replaced it with a bad tensioner. Yes, it's new but there is something wrong with the alignment, a bit too much slop in it or some error in the machining relating to the mounting. Another possibility is that some crud is under one of the mounting holes cocking the assembly or the spring tension is too weak.

I had a car I replaced the water pump on. The pump was new, not rebuilt but there was a minute amount of play in the bearing that translated to a tiny amount of play in the pulley. The belt would not track right. It ran off the edge of the pulley and would have ruined the belt in short order. I had to remove the pump and return it for a replacement. I got one from a different manufacturer because I didn't want to take the chance of the problem repeating itself.

Rock Auto's most expensive tensioner is $70.

What I find curious about your situation is that if the illustration you posted is accurate, the belt is jumping a flange on the PS pulley. That seems very odd to me. Also, if I understand you correctly, the belt is running off towards the engine not away from the engine. I would expect the belt to go the other way if the tensioner is the problem.

Has any other work been done under the hood prior to the belt problem surfacing?

 

[pandemonium]

Hmm, I very much doubt the Ktuned autotensioner is bad. That company specifically designs parts for the K series engines and has been for many years with a stellar reputation.

I can double check the autotensioner's mounting to make sure nothing is preventing it from being seated properly. I made sure when I put it on there wasn't anything built up and that all of the bolts were tightened properly though.

I'll do that and check for any crank pulley play, double check the tracks, and report back if I find anything.

We're pretty confident that the power steering pulley having resistance isn't a problem then?

 

[pandemonium]

Well, I believe I found the problem. The crank shaft pulley is busted and riding on the inside of the shaft. I admit I didn't check that very closely because it wasn't very good light when I did initially, but with the sun shining almost directly in there, I can clearly see the problem.

Thanks for the assistance, ladies and gentlemen!