A/C Compressor Clutch Caught Fire

Discussion in 'The Big Chill' started by Hexafamily, Aug 28, 2013.

  1. Hexafamily

    Hexafamily Member

    Took the GSX to a work sponsored car show yesterday, about a 13 mile drive, mostly highway. On the way there, the car ran fine, but when I pulled off the highway, the engine started to heat up. Drove a mile to the show, and it was getting real hot by the time I parked. After setting all day, and finding nothing wrong, I took the non highway back roads home and watch the gauge. Over the 13 miles it slowly climbed, until about a mile from the house, while stopped at a light, the temperature shot up and the car started smoking. The light turned green and with no place to pull over, I just raced the mile home. When I pulled up to the house and opened the hood, I found the compressor clutch had ignited and fire was coming from the front of the clutch. It was not much of a fire, so I took the garden hose and extinguished it. I cut the drive belt off the compressor, then started the car to try and cool it down while I ran water over the radiator. It took a bit but it very slowly dropped some. Under the hood, the overflow was full and spilling onto the ground. I never ran the A/C at any time during trip to and from work. The car ran fine last weekend and the A/C has been working. So my questions are, has anyone experienced this before and why would the car over heat? The temperature was about 90 degrees with high humidity. After everything cooled off, I checked the clutch and compressor. With the belt off, the pulley spins freely (although burned and damaged) and the compressor turns okay. Not sure what happened.

    Thanks
    Don
     
  2. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Had that same thing happen to me when driving my Dad's '65 Thunderbird years ago. I smelled something burning but due to traffic wasn't sure where it was coming from, then saw smoke coming from under the hood and pulled over. The compressor clutch was glowing red and smoking. Didn't quite make it to flames but definitely was right there. I cut the belt and went on my way. I wasn't running the A/C as it didn't work any ways.
     
  3. SteeveeDee

    SteeveeDee Orange Acres

    The springs on the shoe (the piece that is pulled in to engage the clutch) were weak from wear and allowed the compressor to partially engage, so a lot of heat built up, just like riding your brakes. You'll have to replace the shoe, and potentially the clutch. IIRC, this does not require discharging the system. It's been awhile since I've done one.
     
  4. philbquick

    philbquick Founders Club Member

    If the clutch gap gets too big from wear it will stretch the springs and it won't return all the way so the clutch rubs a little and that generates a lot of heat. I wouldn't think the heat would transfer to the engine but I guess it's possible.
     
  5. tom_gonzalez@ve

    tom_gonzalez@ve Well-Known Member

    Two separate issues, The A/c clutch would have no bearing on the engine temperature. The comments addressing that are spot on. As for the overheating engine- Fill the radiator all the way to the top of the neck and start the engine. There should be some movement of the water as the engine is running. As it reaches operating temperature the movement will increase. There will be an overflow of water also as it heats up, so beware of the hot water. If there is no movement of water, either the thermostat is staying closed, the radiator core is plugged or the water pump is going down.
     
  6. jay3000

    jay3000 RIP 1-16-21

    If you need an oversize clutch, I have one..
     
  7. Hexafamily

    Hexafamily Member

    I agree, they should not be related, but I am baffled why they both occurred at the same time. I am concerned the thermostat is not working correctly, so I will be replacing that. I know the fan clutch is weak. Spins way too freely, even when hot, so I am replacing it too. I am just confused why it worked fine four days prior, but then suddenly overheats. Hopefully its the thermostat.

    ---------- Post added at 09:08 PM ---------- Previous post was at 09:06 PM ----------

    I was leaning toward replacing the whole compressor, due to clutch cost. How much are you wanting for it?

    Thanks
     
  8. jay3000

    jay3000 RIP 1-16-21

    http://www.partsgeek.com/ftdng95-bu...-1981+Buick+Riviera+A/C+Clutch+-+Four+Seasons


    I have only the center part that is shown in this picture if that will do you any good, it's free.. But I do have the bigger pulley version like the cars had that were geared high.
     
  9. lsrx101

    lsrx101 Well-Known Member

    "I am concerned the thermostat is not working correctly, so I will be replacing that. I know the fan clutch is weak. Spins way too freely, even when hot, so I am replacing it too".

    I believe you just put your finger on the core issue.
    If the fan clutch is dead there will be too little airflow over the condenser at lower speeds. This causes the AC Head pressure (High Side) to skyrocket which overstresses the clutch and causes it to slip. This also causes the condenser to run much hotter, greatly preheating the air through the radiator. The preheated air reduces the radiator cooling efficiency leading to the engine running hot.

    This is one reason that many GM vehicles were equipped with a superheat switch and thermal fuse or a high limit switch. Make sure that part of the compressor clutch circuit hasn't been bypassed or eliminated.
     
  10. Hexafamily

    Hexafamily Member

    Thanks for the offer Jay. I think I may have one stuck somewhere if I can just find it. If not, I will get back with you.
    Thanks
    Don
     

Share This Page