"scraping" noise from the fanbelt(s)

[coachsmith]

95 Pathfinder with 195K miles.

 

 

I'm getting what I'll describe as a soft metallic "scraping" noise from the fanbelt area. All the belts can barely be turned 90 degrees and none look to be loose and slipping or slapping (if you can tell that just by looking). While driving under acceleration, the noise will increase somewhat in loudness... sometimes getting alarmingly loud - and it decreases in loudness when I let off the gas. A few times when coming to a stop, it will fluctuate between soft and loud and it sounds as if it is slowly spinning to a halt even though the tach is right below1000 rpms.

 

The radiator fan will spin between a 1/4 and 1/2 turn when I give it a pretty good spin. It doesn't seem to be hung nor is it spinning free. I don't know of any other test for the fan clutch.

 

My uncle thinks it's the fan clutch or possibly the idler pulley... but he's a Ford man and is just going by what I told him. I'm also thinking it might be a bearing in the water pump - which I'm planning on replacing next week along with the timing belt (don't cringe, but it's the OEM pump that came on the Pathfinder! I forgot to tell them to replace it during the last timing belt change.)

 

I had the transmission rebuilt at 165K miles when the reverse went out. It required a rebuilt trans pump among other things. I replaced the radiator and added an after market trans oil cooler to work along with the one built-in to the main radiator. I think the cores slowly crud-up over time and let the transmissions cook themselves. Still, 165K didn't leave me feeling cheated.

 

Right now, I'm avoiding long trips because it's cold and I'm not lookin forward to walking in the cold if it dies on the roadside.

 

Am I going to have to wait for something to just "fall off" or should I just replace every pulley along with the timing belt, water pump, etc??

 

Thanks in advance,

 

Steve

Edited February 13, 2008 by coachsmith

[Simon]

The idler pulley for the AC belt is somewhat common to fail. Easy test....remove the AC belt and see if your truck still makes the same noise.

 

As far as I know, the clutch fan should spin more than 1/4-1/2 a turn.....it may be a combination of both those things.

[94extreme]

what simon said.

[coachsmith]

The idler pulley for the AC belt is somewhat common to fail. Easy test....remove the AC belt and see if your truck still makes the same noise.

 

As far as I know, the clutch fan should spin more than 1/4-1/2 a turn.....it may be a combination of both those things.

 

 

Thanks, guys!

 

- Steve

 

ps. Simon, I appreciate the advice. And -very- cool site, btw. Mzxtreme, thanks to you as well.

[zonianbrat]

If it is not either one of the things talked about above I would say water pump. I had one make a grinding noise on my old pontiac but it lasted a day then it went out.

[coachsmith]

Noise is gone - and I'm 99.999% sure it's the AC belt idler pulley.

 

 

Simon and Mzxtreme nailed it. I removed the AC belt and no more noise! In fact, after looking through this site and seeing how much info is available (step-by-step instructions, pictures, etc) I'm ready to tackle more than replacing a pulley. I'm getting my nerve up to clean out the junked-up garage bay below the apartment and do the timing belt myself week after next (with my mechanic uncle "on call" to get me out of trouble... I ain't no dummy!) I'm not going to fool with putting the AC belt back until then. It's 20 friggin degrees with 30-40 mile per hour gusts and blowing snow... even with a garage it's still Brass Monkey Alert weather here in East Tennessee this week.

 

I cleaned out 2 of the 3 bays this summer after my mom and grandma junked it up while I was off working out of state... and this is just the motivation I need to finish up bay # 3 so I can have a decent place to work.

 

I'll be studying up on the procedure in the meantime... there's a lot of stuff (like that original water pump, lol) I should replace while I'm at it and I want to get the job done right the first time.

 

Thanks a bunch, guys... I'm sure I'll be on here pretty soon asking a bunch of questions.

 

 

Steve

 

ps. The AC belt looked pretty old and was showing some wear so I removed it the easy way - utility knife.

[94extreme]

(with my mechanic uncle "on call" to get me out of trouble... I ain't no dummy!)

 

 

and what, we're not good enough for that?

[coachsmith]

Now that it's a balmy 38 degrees (compared with yesterday's 25 w/30 mph wind), I spun the AC idler pulley and "scrape, scrape, scrape"...

 

Whew....!

 

 

(I had been having nightmare visions of sparks flying inside the block as the crank tried to turn, etc)

 

The best part about the cold snap is that I don't really have to replace it and the belt until it gets a little warmer :-)

 

After _really_ reading the article on changing the timing belt, I'm having second thoughts about the process. Since the valves can get whacked by the pistons if the timing is way off, perhaps paying someone who is experienced do the job is worth the $$$$.

 

I'm thinking projects like relocating the oil filter, or replacing the 60 amp alternator with a 90 amp Maxima alternator are more in line with my ability factor.

 

Anyway, I appreciate the quick replies and the great advice. I'm looking to break 200K by the Fall and my goal this summer is to get my gal spruced up enough to be a reliable daily driver for the next 100K.

 

Steve