So for two years or so, my engine has been making a loud chirping noise on idle, and now it's to the point where it squeals very loud at low speeds. The cold seems to make the noise and everything worse. I have taken the truck to the Ford dealer and the local shop. They have replaced the fan clutch and many pulleys, but none of this has helped the issue. Again, I had to take the truck to the shop today, and they said the AC compressor has a bad bearing and doesn't move at all, so they want to replace it, along with a hose and something else, which will cost $1700. Looks like I'm gonna have to live with this embarrassing squealing for a while. Hopefully nothing breaks, and I'm assuming this is not an easy DIY job.

 

There is another option that will save you a grundle of money. You can actually just remove the compressor and add the bypass pulley in the link below. That said, you would also need to replace pretty much everything else when you get around to doing the compressor - but for $1700 it sounds like that was their plan anyway.

 

So this may be a dumb question, but if I install an AC bypass pulley, then will my heat or defrost work at all? I really need it considering I'm in Colorado.

 

I'd check with some other mechanics. My a/c compressor went out on me and I had a friend who was a mechanic and he got me a new a/c compressor, put it on and filled with freon, for only $250. You can order the a/c compressor yourself for less than $200.

 

Yes, that will all still work.

 

You'll get heat for defrost, but since the compressor isn't running, the air won't be as dry out the vents, so it might take a bit longer to evaporate water off the inside of the windows. On the plus side, the air will be warmer once the engine warms up, which might be a plus in Colorado.


Can't you just unplug the compressor clutch or something? On most systems the AC compressor already doesn't spin most of the time, but cycles on and off via a clutch. Unplugging it usually means it never engages and tries to spin the compressor. Of course, the clutch could be seized and causing the compressor to turn all the time, but those are usually replaceable without replacing the compressor. I unplugged the clutch on my Volvo since it leaked enough freon the system hardly worked anyway and I wasn't going to vent the remaining Freon -- no sense having it decide to try spinning the compressor only to cause collateral damage because the pump had seized up at some point.

 

My suggestion was based off of "AC compressor has a bad bearing and doesn't move at all". But yeah, this will work if you just don't want it to engage. Or you can unplug the A/C switch in the line up on the left side of the radiator.

 

I had the same noise and situation. Ended up being my camshaft synchronizer

 

That's interesting... Did you replace it yourself or did you have to take it somewhere? How were you able to find the problem in the first place? This problem has been driving me crazy for a long time. Thanks.

 

So your saying the compressor pulley isn't spinning at all meaning its locked up? So the belt is moving over the pulley but the pulley not moving which is making the noise?


The compressor isn't hard to change, the problem is that you should have it the Freon removed and after replacing the compressor(and orifice) have the system vacuumed down and Freon and pag oil added.


Wayne