[Kidd-7]

My A/C coolant is low or just plain empty, it's putting a terrible load on the engine when running defrost, etc. I was sitting at a light and I could feel the car almost lurch when the compressor cycled. Thankfully it's not hot enough for A/C yet, but that's coming real quick.

First off; Is running the defrost in this situation going to cause more damage? Should I unplug the A/C clutch to prevent said damage?

I've never worked on an A/C system before; can ya'll give me some troubleshooting guidance?

 

[T6Rocket]

It's a good sign that the compressor still comes on. Once it gets too low, it won't cycle any more and you have to use a jumper wire to get the compressor to cycle to fill it. It might just need filled. A lot of older cars can get by with a fill once a year, or every several years. It's best to let a shop evacuate and replace. It lasts a lot longer, and works much better than the DIY kits.

Does it not blow cold at all? It puts the same load on the car whether the air is cold or not. When my 97 was low, it would cycle every few seconds, which was irritating.

But now that you mention it, my 97 has done the same thing. It sometimes lurches while sitting at a light with the A/C on - it loses brake vacuum and the brakes let go. The air blows cold however (knocks on wood).

Al

 

[dDUBb]

You should never have to top off the AC refrigerant charge, ever. .. if it's low, there is a leak.

 

[supergordo]

If the Ac compressor is coming on, then it isn't TOO low on r134a. However if when it comes on it's putting a huge load on the engine then you are likely dealing with the compressor clutch beaing that is going bac, or the bearings in the compressor are getting bad. If it was really low on r134a it would cycle on then cycle right back off again.

 

[Kidd-7]

Yes, it's a sealed system, if it's low, it leaks. A slow leak can be mitigated by adding r134a.

It did seem to short cycle when warming up in the driveway, combo of being cold out and possibly low. But it did seem to be putting a more than normal load on the engine. The RPMs were really changing drastically, I didn't specifically monitor the RPMs.

If the bearings are wearing out what's your thoughts? Replace it soon, start saving, wait for it to squeal, etc?

 

[theterminator93]

If the engine struggles at idle with the A/C cycling it's indicative of a compressor possibly going bad. When the engine is off you should be able to easily turn the swashplate of the compressor by rotating the front of the clutch by hand.

 

[Derphound01]

R-134a also provides lubricant to the compressor. If your refrigerant is low, which isn't necessarily uncommon for a 25+ year old vehicle, it can cause a RPM dip when it does the quick cycle on and off.

Pull a vacuum on the system to see if it holds. If it does, recharge it to the correct weight and add dye (to check for future leaks).

If the compressor still bogs the RPMs down, check the belt, tensioner, and idler pulleys for wear. If those are all good, it's probably time to order a new compressor, condenser, orifice, and dryer. RockAuto sells the whole kits.

Until then, leave the switch on "PANEL" so it's not incessantly cycling.

 

[theterminator93]

Actually there's no lubrication at all from the refrigerant. There is PAG oil in the system with the refrigerant, which is circulated by the refrigerant as the compressor runs. When the refrigerant runs low, it causes lubrication to decrease.

You can disable the A/C by pulling the pigtail from the low pressure cycling switch on the accumulator so you still have access to defrost.

 

[Derphound01]

Actually there's no lubrication at all from the refrigerant. There is PAG oil in the system with the refrigerant, which is circulated by the refrigerant as the compressor runs. When the refrigerant runs low, it causes lubrication to decrease.

Correct. I should have used the word "circulates" instead of "provides".

I had the same problem with mine when I bought it. Idler pulley was seized up and causing all sorts of problems, including AC issues. New pulley and belt fixed it.

 

[Kidd-7]

As a band aid I added some R-134a. It doesn't bog down any more. I apparently have a leak. Is there an easy way to inject dye without evacuating the system first?
If not, I'll have to have this evacuated & recharged properly with dye to evaluate.

 

[Grog6]

What you will likely find is a shaft seal leak on the compressor, unless you have physical damage. The condenser is a target for road debris, look it over.

 

[Kidd-7]

Will check the condenser, my front end is speckled from road debris and it's time to replace my windshield again. I need a work from home job...

 

[supergordo]

You can usually buy a small can of dye at autozone that has a short hose on it so that you inject dye.

 

[T6Rocket]

Don't you need special glasses to see the dye? You can easily overfill the system with those DIY kits.

It was never mentioned whether or not the OP's A/C is blowing cold or not? Only that the car was bogging down when compressor engages, which the A/C always does.

I also thought my car seemed to be bogging down from the A/C the other day. It was just from not being used to the A/C running for the last 5 months.

Al

 

[Kidd-7]

Yes you need UV glasses and a flashlight, which I can either borrow or buy. As for blowing cold, I have not answered yet because winter decided to finally hit this last week. So yeah it was blowing cold, but not necessarily because it was working.

 

[supergordo]

Don't you need special glasses to see the dye? You can easily overfill the system with those DIY kits.

It was never mentioned whether or not the OP's A/C is blowing cold or not? Only that the car was bogging down when compressor engages, which the A/C always does.

I also thought my car seemed to be bogging down from the A/C the other day. It was just from not being used to the A/C running for the last 5 months.

Al

There are yellow glasses they sell that can help you spot the dye. A UV light is more important. The glasses are not necessary really. Just helps a little. Especially if one is not used to finding dye markers.

 

[Grog6]

Itink I paid $5 for an led flashlight . You don't need special glasses, just don't stare into a uv light. do it in the dark,and it will light up like crazy.

 

[Kidd-7]

Ok found some glowing tonight, now I need help with what parts are leaking. I'll post pics below, but the tube that goes down from the high pressure connection down to a barrel, it's the tube going up to the compressor.

 

[supergordo]

That is the discharge line. What year is your car?

 

[Kidd-7]

it's a 96. 4.6L