Quieter AC operation (1 Viewer)

[COYS]

My FZJ makes it known when the AC cycles off and on. When AC on, it introduces more noise into the cabin in the form of a noticeable buzzing vibration. I'd like to quiet it down as in make it less noticeable like new.

Any tips/tricks or general guidance to smooth things out a bit as I will be using the AC a lot more with Spring/Summer approaching.

Thank you very much.

 

[gummycarbs]

What's your RPM with the engine fully warmed and the A/C active? Off the top of my head, it's supposed to be 900 RPM in neutral/park.

 

[COYS]

What's your RPM with the engine fully warmed and the A/C active? Off the top of my head, it's supposed to be 900 RPM in neutral/park.

Nothing unusual on my rig from RPM side. It's just that when the AC cycles on, again, the cabin buzzes a bit. When off, back to normal quiet.

Would these belts help? Not sure if this kit includes the AC belt.

80 Series 1FZ Complete Belt Kit

 

[gummycarbs]

I didn't ask if it's unusual, I asked what your RPM is with the A/C compressor working.

 

[flintknapper]

Nothing unusual on my rig from RPM side. It's just that when the AC cycles on, again, the cabin buzzes a bit. When off, back to normal quiet.

Would these belts help? Not sure if this kit includes the AC belt.

80 Series 1FZ Complete Belt Kit

^^^^^ The belt kit includes ALL belts (3) for the 80 series (2) Alternator/Drive belts and (1) A/C belt.

But belts are an unlikely source for 'in cabin' vibration.

It would not hurt to check the tension of each belt, just for maintenance sake.

IF the vibration only occurs while at 'idle' then check your idle speed. IF it also occurs under power (acceleration or highway speeds) I'd look for imbalance of any rotating mass and check the condition of your compressor.

 

[Tools R Us]

Check the compressor pulley for play, listen with a stethoscope for noise. It's not uncommon for the clutch bearing to take a dump, causing a rumble.

 

[COYS]

^^^^^ The belt kit includes ALL belts (3) for the 80 series (2) Alternator/Drive belts and (1) A/C belt.

But belts are an unlikely source for 'in cabin' vibration.

It would not hurt to check the tension of each belt, just for maintenance sake.

IF the vibration only occurs while at 'idle' then check your idle speed. IF it also occurs under power (acceleration or highway speeds) I'd look for imbalance of any rotating mass and check the condition of your compressor.

It's more of a buzzing (vibration) than say a vibration as in cabin is shaking. It happens on most all cars when you turn on the AC, just that newer cars insulate you from these noises. Definitely only at idle. Thanks for helping out with the belt info. Ordered!

 

[fj80toyman]

Depending on the buzzing, check the blower fan inside the cabin for leaves or debris as well.

If junk gets in there it can collect and make that type of noise.

Another thing to check for you!

Dan.

 

[thatcabledude]

Engine RPM raising (like normal) causing some wore out/old interior piece to vibrate/rattle.

 

[Golgo13]

Is there any junk in the blower? That could cause a buzzing noise/vibration. Or is it ONLY when the actual pump is running?

 

[COYS]

Is there any junk in the blower? That could cause a buzzing noise/vibration. Or is it ONLY when the actual pump is running?

Not sure. It's an NVH type buzzing vibration the moment when you hear that faint click and the AC cycles on. I'll have my shop figure it out. Thanks, all.

 

[GA Trevor]

Sounds like a 20 year old car problem, I wouldn't fret it

 

[COYS]

Sounds like a 20 year old car problem, I wouldn't fret it

I underestimated how raw these 80s are. Back in high school, my buddy had a new one and during that time, it felt so normal (until he rolled it into a ditch).

Starting to need an A.F.I. attitude with this tractor of a tank of a truck. Ahhh F It.

 

[MikeB]

You might want to check the idler pulley. When my idler bearing started going bad, the vibration was only really noticeable with the compressor on. Take the belt off and spin to idler pulley by hand to see if it is tight and smooth. You easily find a generic bearing and replace it in the pulley if yours is bad.

 

[Dave 2000]

My diesel has an 'idle up' switch when the AC compressor starts, this prevents the load lowering the idle too much, I would test in neutral and in 'D', if the OP is auto? I think the petrol version has something similar but may be ECU controlled ?

When the idle is too low on my 80 there are some odd rattles here and there but, I found the pipes that went to the rear heater were rattling against the bulkhead. They had to come out anyway due to tin worm, and I have no doubt the rubber insulators on the motor mounts are past their best.

By coincidence I have just ordered a new set of OE mounts for mine as part of PM.

Regards

Dave