Has it happened to anyone or it is unique scenario in my case? It is still very rainy here in FL and every time I go through deep water, it splashes to the alternator and makes the belt to slip for a short time. I can see it on the charging needle, it drops sometimes as low until the charging light comes on. Plus a metalish noise is coming from the front of the engine and I assume the alternator’s bearing does that. This noise is not continuous, it’s loudest mostly at cold start. My car’s got 135xxx miles and the alternator is one of the part I haven’t replaced yet.
I appreciate any comment about this.
Thank you.
Joe, my car did exactly the same thing in winter, disappeared when spring came along. A pal told me to spray a shot of WD40 “down in the front of the motor” and see if the noise goes away …it did, immediately. The car would be ok for about a week then it’d do it again …squirt, repeat etc.
I was surprised as it didn’t sound like a belt noise, but a as you say, “metallic” and usually just on cold start.
I’m convinced it’s a belt noise, (in my case I think it’s the compressor belt) and have three new ones on hand, ready to replace, however, haven’t got round to it yet as it’s summer and there isn’t any noise so the lazies have taken over …
Hey Joe … (sounds like a good name for a Jimi Hendrixs song !)
From what you describe it sounds like the fan belt that drives your alternator is slipping.
Since it only occurs when the belt is wet (the water acting as a lubricant) that makes the most sense.
Try rubbing or spraying some belt dressing on the alternator belt. This should eliminate any oil or grease that may have gotten on it. If that fails to fix the problem the next step would be to tighten the alternator belt adjustment as belts stretch over time resulting in not enough tension on the alternator pulley. If that doesn’t work you’ll have to replace the belt.
As far as the alternator itself if it’s working normally with no noise unless it’s wet then that’s not your problem.
If the alternator bearings are going bad you’ll hear it all the time. But to make sure take a car stethoscope and place the metal rod on the alternator, if the bearings are acting up you’ll hear it. Don’t have a stethoscope…? Pick one up at Harbor Freight or any auto parts store. Don’t want to buy one (cheapskate) take a coat hanger and tape it to an empty soup can. place the coat hanger on the alternator and listen at the open end of the can.
Of course there may be other reasons for the screeching noise !!!
Larry, Grooveman,
thanks for the replies. I think the alternator bearing is about to go. It’s getting worse and worse. Sometimes I get that screeching noise during driving or when I park my car. The belts are in good condition and tightened properly. I replaced them about a year ago. I just wanted to know if it’s normal for the alternator to get wet or the plastic under panel is not doing it’s job properly.
Not in my case, I had a “screech” last winter but it disappeared as the weather warmed up.
As I said above, a squirt of wd40 stopped the screeching immediately and the effect lasted about a week before I needed to squirt it again …
If it is the crank damper, the first thing I would try would be a steam-clean of the damper then a big slosh of krazy glue all over it. Theory is, enough super glue will penetrate the separated seam to effect a new permanent bond …certainly worth a try, eh?
Hi Joe, you can even use a long handled screwdriver as a stethoscope for a one off job like your alternator bearings.
Or, slacken the belt and slip it off the alternator pulley and try spinning it by hand to see if it’s completely free and has no play when you try to rock it.
Even quicker is Larry’s method with the WD 40. if the bearing is worn and noisy the WD will immediately mask it and you will hear the alternator run quieter for a short spell, even if it isn’t screeching at the time you will hear an immediate change in the noise if the bearing is worn.
My car was around the 135,000 M like yours when the alternator started giving problems.There was so little of the carbon brushes left I was surprised it had worked at all, I never thought it was particularly noisy I replaced it because it stopped charging, but the replacement sounded so much quieter !
If the bearing has been binding when the alternator is under load and the belt screeching because it’s slipping, it would be wise to replace the belt along with the alternator anyway, even though you only did it last year.
My car doesn’t have an under panel and we get lots of rain here and plenty of deep puddles on our local roads, I don’t know for sure if my alternator stays dry or not, but I’ve never heard it screech because of the rain and wet conditions.
The last time I had the problem occur my drive belt looked fine too, no cracks or chips anywhere but it had to be adjusted far too tight to use before the noise stopped.
I think once they have slipped to the point of screeching for a while, the grooves in the belt get sort of burnt and polished and lose friction and then need too much tension before they grip properly.
good luck, hope it’s fixed soon whatever it turns out to be.
Thanks for chiming in. I sprayed some WD40 to the alternator. The noise went away like usual but at sudden rev up I heard that noise again. I stopped the engine, sprayed again but the result was the same. I start to think that Bryan’s theory and my 2nd guess is the source of the problem: crank damper pulley.
if the problem is the harmonic balancer then I’m going to send it to Dale manufacturing in Oregon. According to their website they charge $115. But they’re closed in every 3rd month so I gotta wait until July. Damper Doctor in CA gave me a $275 price estimate.
