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HybridZ

Train-wreck from under the hood


4x4nismo

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Hi guys, "new" to the forum (I've observed for a few years as a guest, never posted).

 

I have a squealing problem!!

I've had my car about 5 years. The problem started the first winter after I bought it- during startup there would be a horrible loud, ear-pounding scream coming from under the hood every few mornings. Any slight tap on the gas pedal, problem was gone. As soon as the winter passed the problem went away. Came back the year later, gathered up my money and had all the belts replaced (and plugs, wires, timing belt, etc etc). The next winter, the problem came back, but it was daily for about a month- same thing, tap the gas and we're good to go. Had a few mechanic buddies look at it over the summer, belts were re-adjusted, no fix.

 

This year, the problem started before the temp even dropped. Every morning, horrible squeal. If the squeal starts right away, sometimes turning on the A/C or headlights, or steering back and forth quickly makes the squeal stop (so does getting the RPMs up above 4k). If it Doesn't squeal on startup, it Does the second i turn on my A/C or headlights.

 

My lights never dim, voltage never drops, and the A/C never stops working when the squealing persists. This last month, sometimes if I go through a large puddle of water it starts back up. I had someone recc'd soaping my belts- worked for 2 days. I've tried belt squeal remover- an entire can works for maybe 2 days. The last few weeks, sometimes after driving a long highway distance the squealing will start up out of nowhere (after an hour of no problems). The last few days, while driving in city traffic during cold weather, the squealing is next to impossible to stop unless I take the car out of gear and floor it to 4-5k. That usually fixes it for good, unless I turn on the A/C.

 

As you could guess I'm no mechanic; but I did try removing the belt from the A/C condenser- did not fix the problem. The alternator tests fine and was replaced about 1 month before I bought it (I kept the same mechanic as the original owner, until I moved).

 

I've been reading through the forums; I'm starting to suspect that it might be my fan clutch. I've Never had an overheating problem, though- car only hit above the halfway mark Once, driving in stop-and-go traffic with the A/C on max and the temp at 110 (TX summers are great). But from what I've read, that isn't to say that my fan clutch is fully functional...

 

At this point, any ideas are appreciated. Unfortunately I don't have the know-how/equipment/another car to be able to tear my car apart as much as I'd like, nor do I have the time or money for a half-*** mechanic (who has never even heard of my car's model) to try and fix the issue.

 

Thanks!

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I second the alternator belt slipping theory. The Z31s seem to want more tension in the alternator belt than even called for in the manual to not slip when under a heavy electrical load. It's a rather tiny belt, and the alternator can load the contact area really hard, there's not a lot of wrap around the pulley so it can slip fairly easily. Most newer cars have idler pulleys to wrap the belt around at least 50% of the alternator pulley.

 

It makes sense to have more slippage in cold weather or with any additional electrical loads, as your battery voltage will drop and want more of a boost to bring back the power you used to start the car. The voltage doesn't seem to drop as the alternator is putting out enough power, it's just working extra hard and is having trouble stealing enough power from the belt to keep up.

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How old is your battery? If the battery is weak the alternator may be under increased load because of it. Turning on the lights increases the load and causes the belt to slip. Could also be a bearing going that in increasing the load cauing belt squeek.

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Are you sure? In what way?

 

 

Its the damper.....

 

 

The ruber in the damnper is rotted. You said when you drive through water it will squeel also. So open the hood and hit the damper with a water hose. I have seen the belt and accesories stop before. It may not be thee damner but my money is on it.

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Its the damper.....

 

 

The ruber in the damnper is rotted. You said when you drive through water it will squeel also. So open the hood and hit the damper with a water hose. I have seen the belt and accesories stop before. It may not be thee damner but my money is on it.

 

I'll have to give this a shot- I didn't think to try and duplicate the situation in this fashion.

 

As far as my battery goes, I bought a Yellow Top 2 years after I bought my car. It died under warranty (long story..) and was replaced with a new one about 9 months ago.

 

If it were the alternator belt slipping, would my interior and/or headlights dim? My voltage doesn't fluctuate when the squealing starts.

 

Also, something I forgot to mention; when the squealing starts on a very cold morning (sub 40), the squealing seems to be a bit.. slower (longer delay between the chirps), and not As bad (still LOUD, but not painfully so).

 

I'm half-tempted to just replace the fan clutch just to see if that fixes the issue.Car's rolling up on 25 years, it will need it soon regardless.

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I have the same problem, but don't wanna overtighten the belt, so I live with it, I have no mechanicle fan on my car so there goes that part of the theory for me.... i figure if I tighten the belt much more, I'm causing premature wear of h20 pump and alternator bearings.... doesn't bother me too much, Ive also heard that might be a bent pulley..... could probably tell just by watching the pulleys.... I am going to remove my alt, and h20 pump pulleys, and sand blast them.... and do the harmonic also... hopefully that cures it for me...... but when I will get around to it?????

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so you have not tested the damper yet?

 

I didn't bother. I went out at night (when it was nice and cold) and gave it a good listening with what was said in this thread in mind. As the noise goes on, the fan spins slower (less fan noise and air being pushed), and when watching it spin while squealing you can see the outline of the fan blades start to "wave" as if the fan is moving or the speed is alternating rapidly. half a second after the squealing stops (by revving the engine) the fan speed picks up, more air is pushed, and the fan can actually be heard. If I leave everything alone, it starts squealing and the fan speed slows down again.

 

I'm no mechanic (and I should have paid more attention originally) but I'm pretty sure you guys have helped me figure out my problem. I feel like I'm still kinda shooting in the dark, but if this doesn't fix it then I will at least know that it is Not my fan (or a/c, or a/c pulley).

 

(again, if it Were the alternator, I would see Some sort of fluctuation in voltage when the fan starts squealing, correct?)

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Replaced my hood struts, steering wheel (Momo evo rox!!), and fan clutch. 100 arm scratches later (damn fan shroud), I crank 'em up, and squealing starts. A few tears roll down my cheek, I let it run for maybe 15 seconds, then give each belt a quick feel. My alternator belt is noticeably Hot, just from 15 seconds of squealing. I adjust the tension, problem doesn't change. I adjust a bit more, problem gets worse. I think I found my problem!

 

My other belts were replaced with normal ribbed belts. My alternator belt has some odd tire-tread-lookin' setup. I pulled my receipts from the belt change and noticed it was a "gator-back" belt. Is this a normal belt for our alternators? Should it be ribbed like the others?

 

I've never messed with my belts before so it might just need to be properly tensioned.. we shall see (as soon as I find out how to do that!)

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  • 2 weeks later...

yah... 45 minutes and 2 wrenches, the problem is gone.

 

whose an idiot? this guy.

 

the frickin' belt needed to be tightened. at least i don't have to worry about the fan clutch going out anytime soon... thanks for all the help!

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