Every time I start the vehicle I hear a tapping noise that is getting worse. I appears to come from the area where the alternator belt is located. The alternator does not seem to be spinning when the belt spins. I would like to show a video of it please. Any suggestions on how to diagnose this issue?? I am a “hands off” mechanical engineer. I know the theory but have no practice on it.
Start with a voltmeter. At rest, ignition off, the battery should read about 12.5 volts. Watch the voltmeter when younstart the car. It will drop to about 9 to 10 volts but should pop right up to 13.5 to 14.5 volts once the engine catches. If it doesn’t, the alternator may be failing.
So remove the serpentine belt and turn the alternator by hand. Does it spin smoothly? Or feel rough? My thought is the bearing in the alternator is failing and causing the belt to slip. While belt is off, rotate the idler pulleys, power steering pump, if it has one, and water pump checking for the failing bearings in one of those.
2 Likes
Thanks,
I am buying the multi-meter right now. I have gloves and a few tools. What else do you think I am going to need? what should I use to clean/lube the engine so I don’t get too dirty while working on it and make it shiny.
Getting dirty is part of working on a car. If you insist, there are special spray cleaners that you can buy specifically for that job. Take the car to the coin-op high pressure spray wash and follow the directions on the can. Don’t over-do it and spray blast the electrical connectors. They don’t like that. Use aluminum foil to protect fuse boxes and such.
You’ll likely need metric open end wrenches and a 3/8 metric socket set with some extensions plus a 1/2 breaker bar to swing the belt tensioner out of the way. A pry bar is nice as are a set of screwdrivers.
And there is no lubing of the outside of the engine. The important parts needing lube are INside. The belts don;t like ANY lube AT ALL. Rinse off all the soap, don’t spray the cleaner on the belts if you can help it.
if you take a video of it, the easiest way to show it here is to upload it to Youtube and link to it here. This site unfortunately doesn’t really have a nice easy way to upload a video
I prefer to just carefully wipe down everything I can reach with a microfiber cloth sprayed with quick detailer. It might not look perfect, but that way I’m sure I’m not getting moisture into any components that aren’t meant to get wet.
I think that most everything under the hood gets a little bit wet when driving in the rain. I’d take off the engine sound cover, put plastic bags on the electronics, spray the cleaner, and carefully use the spray wand to rinse off the cleaner.
You just diagnosed your problem. Remove the belt and hand-spin the pulley, unless it freely spins, replace the alternator.
3 Likes