Alternator running hot

[gerhardm]

I notice a burnt smell in my 2003 Envoy's engine compartment. The alternator appears to be running hot (the alternator housing gets very hot after only a few minutes of running). The alternator still appears to be charging the battery just fine but I noticed a "whining" noise coming from the alternator lately. Has anybody else had a similar problem?

[maxwedge]

They do get hot normally, I would check the voltage output, see if it is within normal range, also check amps if possible, make sure the pos cable on the alt is tight and the battery and ground cables are clean and tight also. Can you trace the smell to the alt. My TB does this for days after changing the oil and filter as some oil gets on the block.

[rodeo02]

If you are getting noise & heat from the alternator, the inboard or outboard bearings are probably shot on it. Only way to tell for sure is pop off the serp. belt and spin the alt pulley. In my experience, GM alternators are not the best in terms of longevity.

Joel

[gerhardm]

Thanks for the tip. I can trace the smell to the alternator. I removed the V-belt to check the alternator and idler pulley. While the idler pulley seems fine the alternator makes a squealy noise when turning it by hand. When running the engine the alternator makes significant noise. I suppose the alternator bearings or at least one of them has gone bad and the smell probably comes from burnt lubricant. Time to run to Murray's and get a rebuilt alternator...

[gerhardm]

I have replaced the faulty Delphi alternator with a brandnew alternator from Bosch and everything works fine. The new alternator will probably outlast all the other Delphi parts on this vehicle .