Squeal starting at 6200 RPM (sounds like a belt)

[mxr662]

There is a squeal at about 6200 rpm which gets louder until the cars shifts and rpm drops. New belts, water pump. Forgot to get the pulleys when last ordering parts, but pulleys will be ordered Monday. The existing pulley bearings seemed fine. Did not check the tension of the old, very warn belts before removing them and never ran car at high rpm's because of original timing guides, so I'm not sure if it squealed before. I am unclear about how tight the belts should be. I have really no idea how tight they should be. KG of pressure and deflection in mm seems impossible without a tool. I tightened the belts a bit more but no help. They seem quite tight. Could they be too tight?

Andy

[carfrk666]

ya mine does the same thing, and i have kinda old belts on it, its from the belts not having enough tension on them, they are slightly loose so at high RPM and they stretch and start to squeal.

[DrewQ45]

If memory serves me correctly, there should be no more than .25 inch of deflection given human effort. Make it too tight however, and your water pump gets eaten in very short order due to stress on the bearings. Have someone rev the engine while you spray WD-40 on the belts one by one. If it quiets, you'll know which belt it is. Get a long straw and use it as guide to drip the WD-40 as you can never get close enough to spray with the fan running.

Somehow though, I doubt it's your belts.

[maxnix]

There is a squeal at about 6200 rpm which gets louder until the cars shifts and rpm drops. New belts, water pump. Forgot to get the pulleys when last ordering parts, but pulleys will be ordered Monday. The existing pulley bearings seemed fine. Did not check the tension of the old, very warn belts before removing them and never ran car at high rpm's because of original timing guides, so I'm not sure if it squealed before. Andy

Must at least refer to the FSM.

Never use WD-40 as a bearing lubrcation especially, and keep it away from rubber.

[StarPD]

Must at least refer to the FSM.

Never use WD-40 as a bearing lubrcation especially, and keep it away from rubber.

I agree wholeheartedly. WD 40 is nothing more than de-scented kerosene, and should not be used as a lubricant anyway. It's a great solvent, but doesn't last as a lubricant. Spray it into bearings and it will dissolve and carry away existing bearing lube, causing it to seize.

There are belt sprays that can help belt traction, but care must be used when spraying anything on belts and around parts like alternators and on painted and plastic components. Moderation is the key when doing this.

There are tools that measure belt tension. The manufacturers usually provide common belt tensions for given applications (alternators, water pump, etc.) and belt sizes. Absent access to one of those, using two rulers or a ruler and a straightedge can work. With the motor NOT running, lay the straightedge across the tops of two pulleys that are accessible and the furthest apart parallel to the belt. Place the ruler perpendicular to the straightedge and against it so the ruler can be read, 90 degrees to the belt. Push down on the ruler and measure the distance you can push the belt from the straightedge. Usually you can only hold the ruler tightly enough to push it far enough to get a reading. Don't try to push TOO hard. This is not a muscle demonstration. Of course, be careful to not cut or chafe the belt with the ruler. 1/4" is a reasonable measurement to use for most belts.

Unless belts are new, suspected belt squeal is frequently cause to replace them. They aren't that terribly expensive, and should be replaced if not necessarily regularly, then at least when aged and in the presence of squealing. Note that belts can be shot and not look like it from the top. The bottom, or friction side of the belt is what counts, and often glazed and sometimes even cracked conditions aren't readily apparent until the belt is removed.

Also consider that an accessory that is driven by belts may be on the way to failure and putting more load on the belt than the belt can overcome at higher speeds.

Let us know what you find is causing your squealing when you isolate and repair it.

[DrewQ45]

Must at least refer to the FSM.

Never use WD-40 as a bearing lubrcation especially, and keep it away from rubber.

Not sure if that meant my advice. At no time did I suggest using it as bearing lube... hello? Turn off the sirens please...WD-40 is a great tool for squeal detection which is the guy's problem. Use by process of elimination. I've only used it for 20+ years...LOL When you find the culprit, you fix it. Use belt dressing (spray can) if it makes you feel more comfy.

[Skibane]

If the squeal is still present with the climate control turned off, you can probably rule out the AC compressor belt...

[Q45denver]

Most likely your idler pulley tensioner bearings need to be replaced.

[Jesda]

Its pulley time.

[nuQ]

definitely sounds like the pulleys, not a belt. mine did the same thing and after changing all the belts the squeel remained,,,,,pulleys

[elwesso]

Definitely take the pullies off and see if they roll smooth. If not you can replace the bearings.

[mxr662]

Removed the pulleys and the bearing seem ok, but will replace bearings tomorrow. There is a NAPA store with a press near my work. Maybe I got the 2 narrower pulleys mixed up before. The alternator/water pump pulley is wider so I know where that one goes. But the AC and PS tension pulleys are same width only one has a slightly larger diameter. The smaller one has 0112 stamped on it and a blue dot. The larger one has 9Z28 on it and an orange dot. Which pulley goes where?