So my 1980 rx7 has this squealing noise at starting at 3000 rpm. I removed the belts and of course the noise is gone. So thinking it was belts or water pump issue I replaced both (it was time anyway to refresh these parts). So after that the noise is still present. If I tighten the belt tension (more that it should be) this caused the noise to start at a slightly higher RPM. So is the fan clutch known to squeal but not fail? Or is there another issue that I should be looking for? If its the fan clutch is there an aftermarket one that is available?

 

One cause can be a bad alternator bearing. Another is if the air pump is removed, the water pump pulley doesn't have enough tension with only one belt.

 

If you have multiple belts, try removing each one to narrow it down. Could be a component thats dragging and causing the belt to slip like the AC or air pump or possible the clutch fan. Of you think its the fan just remove it as a quick test and see if that helps.

 

Another, quicker test is to spray WD40 on each belt pulley until the noise stops. This tells you which belt and/or which component bearing is causing the noise. Typically, if you're hearing this at a specific RPM, it's due to belt slippage. Loosen belts and take some 180 grit sandpaper and lightly sand each pulley to remove the varnish left by the belt. Sand in a perpendicular pattern against belt motion. Also, buy quality belts - I like Gates.

 

Probably are the belts themselves.

A friend of mine had the same problem....no matter how loose or tight the belt were the will always squeal. He ordered straight from Mazda the belts without ribs and problem solved...

You can try that ...

 

Thanks for all the input. I was thinking that since I did remove the air pump some time ago that this could have changed the loading on the water pump pulley. But I did not notice this issue when I first removed the air pump. That being the case I was leaning more toward a failure of the fan clutch. Playing with belt tension changes the point that the squeal starts so I plan to remove the fan and test it without a fan with a normal of even low belt tension. I think that doing this may hide the issue since without the fan load on the pulley it may just change the torque load applied to the water pump pulley. I will try this then see what happens. I may also look at a slightly shorter fan belt so the alternator position puts more belt contact on the water pump pulley. Thinking more contact on pulley makes it harder to slip if that is what is truly happening. Update to follow.
Best Regards to all,

 

Be careful monkeying with overtight belt tension - the front bearing has to shoulder this load, and putting side loads on the bearing in excess of FSM spec is a good way to damage it. Since you mentioned removal of your Air Pump, your water pump pulley has lost some of its traction. There's a reason why a Dual Sheave Alternator pulley exists, and it's to restore belt traction across the eccentric shaft, water pump (*and fan), and alternator WITHOUT cranking up tension on the belts. I run Dual Sheave Racing Beat alternator pulley and 2× belts because I can't risk reduced water pump efficiency, living in the desert.

Additionally, belts are designed to stretch. Overtight belts will simply stretch more, and then fail. Do it right, or risk damage...

 

If you removed the air pump, you need a dual sheave pulley on the alternator so you can run 2 belts for the fan/water pump. Belts should give about 1/2 in when you press on them hard, any tighter and you have em too tight.

 

Somebody should make a spring-loaded tensioner wheel to mount on the front cover somewhere, like modern serpentine belts use. I have thrown belts with a dual sheave pully set-up and destroyed my dist. cap (Air Pump removed), but over-tightening the belts wears out your early.

 

This reminds me of when I purchased my 1975 REPU (sold this last year). A previous owner had removed the air pump and put on a header. In place of the air pump, they had rigged up a bracket with a pully that mounted where the air pump did. I've never seen this before. And like a idiot, I removed it and replaced with a double pulley and threw the rigged pulley away. It worked better then the double pully.

 

Not an expert, but tightening is a sure way to **** your day up. Go with Mazda or Gates belts, I used a long THIN screw driver to tension the alternator up .

 

Sometimes the answer to a problem seems so simple once you have found it. After reading all the replies to this post I started to think about all the possible reasons and types of fixes. Two post suggested getting Mazda supplied belts. This got me to think about this car when I purchased it new back in September of 1979. Back then a notched belts did not come on this car, I don't think that they where as common as they are today. So because this idea was easy to try, I just went to NAPA and purchased a A31 belt without notches. This old type belt has a slightly different width than the ones that you would get if you purchased a replacement for the car using the more common supplied notched belts. In my case I just used what Rock Auto supplied. The notched belt has a top width of .41 inches and the old school A31 NAPA belt is .5 inches. I installed it with a normal amount of tension and problem is gone, revs up to 6K no squeal.
Best Regards,
MJG

 

Always start small . A few months ago I was smoking thick white clouds after the car would warm up and only during idle , much contrary to the typical coolant leak where the white smoke gets better as the engine warms up . I asked and people kept telling me I had a blown water jacket or a blown oil control ring. The issue was my engine had 3,000 miles on it and I had never overheated .
I checked my oil daily and rad levels and there was no dip in fluid. I asked all the rotary mechanics near me and they all preety much told a rebuild was in need or at the least my intake manifold was leaking.

I also noticed my automatic transmisiom fluid was always low even though I had no leaks
So I said " what if my engine is sucking up ATF" . I was told this was impossible but I had my doubts so I tracked down the FSM and looked for every pipe that ran from auto trans to engine only to find one , the vac modulator . 32$ on ebay ( manufactured in 1978 LOL) . I hacked up a gas filter and spliced it between the pipe and turned my car on .. Within 20 seconds a drop of ATF wept up into the filter . It would take about 15 mins to get to the point the engine would suck it up and burn it and the smoke would start up.
The part took 5 mins to install and my issue was solved , but for a while I scared my self into a few thousand dollar issue when the real issue was a simple 30$ modulator .

Also , for any one with a squeeky belt , DO NOT OVERTIGHTEN it , it will destroy your alt bearings and at worse your pully bearings. Do what he did!