1981 380sl that makes a whistling sound inside when the air blower motor is running Is there some way to stop the whistling?

Answer 1

It sounds like you have a bad blower motor. I don't know if you're hearing a whistling sound, but a bearing sound. I had that same problem once. By letting the blower run at different speeds, I was able to get rid of that sound. If that doesn't stop the noise, you'll probably need to replace the blower box. However, since I obviously can't hear the noise in person, there's one other thing you can check. You might have a vacuum leak in your system. A whistling noise could be a broken diaphram. There are 4 of those vacuum units inside the dash area. If you have a vacuum pressure guage, you can hook it into the system, run the heater, and see if there's a leak in the system...you can also check each unit separately...but you will have to remove the glove box and possibly the instrument cluster and radio to access these vacuum units. Other than what I've mentioned, I don't know what else it could be. My guess is, its a vacuum module. Remember, if one starts to go, the others are not far behind...and since accessing these units can be a pain in the ass, you might want to check, and replace the others as well. Also, you want to check all the air lines and connections for leaks. A honest mechanic might be a good way to go too...this stuff can be a nightmare if you don't have good mechanical skills.