When starting my 1991 Civic LX (1.5 liter, manual transmission, no air conditioning) for the first time each day, I hear a loud screech. It lasts about two seconds. I then drive as usual with no funny noises. Driving for 20 minutes, then stopping (car off) for 20 minutes, and then starting again does not give me the screech. The screech began after I did some maintenance on the car the other day. This maintenance was: -- Replaced the alternator belt, setting tension correctly (I think) for a new belt (7-9 mm). -- Partly drained the power steering system, removed the power steering belt and pump, and then re-installed all. The old power steering belt looked fine, so I did not replace it. Again, I think I set the tension correctly. (I removed the belt last week and then re-installed it and did not have this screech.) I followed the procedure at http://timingbelt.soben.com/ to purge (I hope) air from the power steering system. -- Removed the timing belt, installed a new front crank seal and a new camshaft seal, then re-installed the old timing belt. My first guess was that I have somehow messed up either the power steering belt's tension or the alternator belt's tension. I have checked both, and they seem fine, albeit I'm not using a belt gage. Just pushing in the middle of the belt with a finger to the tune of I hope 22 lbs. and then measuring the deflection. Except for this screech at cold startup, the car drives great (so far, after some 35 miles). Any suggestions to diagnose this?
I would guess that it is a slipping belt. I don't know which belt is slipping. However, you may be able to figure it out by raising the hood and watching the belts as a friend starts your car. You may get lucky and actually see or hear which belt is slipping. You should visit a auto parts store and see if they can sell you a spray that may be called something like "Belt Spray" or something like that. I know that they sold it several years ago when I was having a problem with a slipping belt. I don't think that it is the timing belt. If it was slipping, your car would not be running so great.
================= Same happened to me after I did my timing belt. I just had to tighten one of them tighter. Try starting up with the heater fan, headlights, cigarette lighter, rear defrost, radio, wipers ON. If it's any worse, you'll know it's the alternator one. Simple. Those belts have to be pretty tight. You can also squirt a fine mist of water at the suspect belt and see which slips. Harder trick than other. Gets face wet. 'Curly'
Thanks Jason and Curly for sharing your experiences. You all were pretty much right on. It was the new alternator belt. For the archives: I had "Sharpie ink" marked the alternator adjusting bolt slide before removing the old alternator belt, indicating where on the slide the bolt lined up. But I did not adjust the new alternator belt to the same point. My "guesstimate" of the belt deflection seemed to support this. Wrong. This morning I increased the tension to just a tad shy of the old belt's mark. No more morning squeal.
