Video Inside: Need to replace A/C clutch plate? Also expanding gas tank?

[BOX88]

Car- 1988 Caprice

Decided to start her up and take the caprice for a spin last week, winter is here so I had to turn on the heater and use the defroster for a while. While idle at the light I kept hearing this annoying sound from under the hood. Pulled over and checked it out and took a quick video with my phone.

Note!-It also does this when the AC is on.

Here is a youtube video link

http://youtu.be/waLlsp8pgG8

Also not sure if this is a issue with the vapor canister or not. But during the night I hear this LOUD bang from my car, and it only happens during the night. Every time I have to get up because I think it's someone messing with my car, plus my dogs go crazy. I later found out that its my gas tank expanding and making the loud bang noise. I decided to loosen my gas cap and I can feel a lot of pressure releasing in every turn. If I twist it off really fast the tank makes the noise too. I thought maybe something to do with the cold weather, but it also does this in the summer too. Then I figure maybe the vapor canister under the hood is bad or a bad gas cap. None of my other caprice ever did this, and never experienced this issue so I thought it was weird and wonder if this has happened to anyone else.

[silicon212]

Your compressor is not running very long - this can also indicate a state of low refrigerant. The sound could be a slipping clutch, but it could also be the compressor itself.

The compressor runs obviously with the A/C on, but it also runs with the defrost on, due to the fact that cold air is much more effective at defrosting a windshield than is hot air.

As for the gas tank, change your cap!

[j cAT]

Originally Posted by BOX88

Car- 1988 Caprice

Decided to start her up and take the caprice for a spin last week, winter is here so I had to turn on the heater and use the defroster for a while. While idle at the light I kept hearing this annoying sound from under the hood. Pulled over and checked it out and took a quick video with my phone.

Note!-It also does this when the AC is on.

Here is a youtube video link

http://youtu.be/waLlsp8pgG8

Also not sure if this is a issue with the vapor canister or not. But during the night I hear this LOUD bang from my car, and it only happens during the night. Every time I have to get up because I think it's someone messing with my car, plus my dogs go crazy. I later found out that its my gas tank expanding and making the loud bang noise. I decided to loosen my gas cap and I can feel a lot of pressure releasing in every turn. If I twist it off really fast the tank makes the noise too. I thought maybe something to do with the cold weather, but it also does this in the summer too. Then I figure maybe the vapor canister under the hood is bad or a bad gas cap. None of my other caprice ever did this, and never experienced this issue so I thought it was weird and wonder if this has happened to anyone else.

when the air temp goes below 40degf the ac comp when on a cold engine will for sure short cycle as the temp drops so does the pressure.

recharging in cold weather I would not do. wait until its 75F or higher.

the fuel tank excess pressure is most likely the canisterplugged up also the controlling venting valves connected to it. if you park the vehicle after filling to the top you will get the canister damaged from liquid fuel making the charcoal a black fouling goo that plugs up these systems..

on engine shut down gas vapors are sent to the canister to be stored it the pressure rises too high the valve is to release pressure also the cap at a higher pressure should release pressure. when the enginne starts the valve now connects the canister to the intake vac port so that the vapor is consumed.

the clutch plate may be rusted and this will make scrap noise. the way to check this is to get ac gages and see what pressures you get when the weather warms up. 1988 would be R12. if this was converted to R134 with the conversion oils it is possible the seals are leaking for sure.

when you recharge use the dye. then black light for leaks.