Idle problems only with a/c

[97TaurusGuy]

I am experiencing idle problems only when the a/c is on. The idling will drop down to 500 and go up again to about 1200 and repeat. It even drops down a bit when I am driving with the a/c on. It also blowing warm air but I assumed it just needs to be recharged. Also, you can hear the compressor cycling on and off. This s when the engine drops is when the compressor kicks on. When the compressor turns off, the engine goes back up.I did use the search and didn't find anything relevant. I am hoping for some replies this time. Any ideas??

[Gary1234]

Sounds normal for an engine running a/c with no refrigerant.

[shorod]

Sounds like you might have a Idle Air Control (IAC) servo that is not working like it should as well. The IAC should adjust the engine idle speed to compensate for the added load provided by the A/C compressor.

-Rod

[Gary1234]

You can figure out if it's the a/c or a sensor by unplugging the a/c clutch (2 wire plug near front of compressor). If the problem is a sensor, the idle will still vary between 500 and 1200 rpm ... If the problem is the a/c mechanics, the idle should run at normal 750 rpm.

[zorobabel]

Originally Posted by Gary1234

Sounds normal for an engine running a/c with no refrigerant.

Hi every body,

This is my first post here, out of a long line probably. I've been silently reading the Taurus forum for a while now.

I have the same rough idle issues (although it doesn't go bellow 700 rpm) , but that doesn't bother me. What bothers me is the lost effectiveness of my A/C.
I've bought my '99 Taurus Wagon 3.0 Duratec in February at 109000 miles. Back then the air conditioning seemed up to the job. But now as the temperature rose, the A/C blows rather warm air when it is hot outside. When it drops bellow 70F outside, my A/C starts blowing cold air again, so I know it is partially working.

Do you guys think I should add more refrigerant? And how do I check the refrigerant level? Or is it something else? Can anything be done? And how?
I have to mention that this is my first car ever, and I'm short on cash too, so I'd like to do myself any repair possible.

Thank you for reading and hopefully posting!

[Gary1234]

A 16 oz can of refrigerant should be enough to keep your A/C running for a couple of years .. refrigerant leaks out naturally over a long period of time (that's why most systems work for about 5 years before they need a recharge).

A recharge kit (gas and input line) should come with instructions ... I usually inject the refrigerant SLOWLY (over a period of 10 mins or longer) into the low pressure side (at firewall) with engine running and A/C on. If you inject the new refrigerant too fast you run the risk of compressor damage due to hydrolock.

[MyTaurus8AChevy]

Originally Posted by Gary1234

refrigerant leaks out naturally

Are you sure about this? Others here have said that it is a sealed system and you only need to add refrigerant IF a leak occurs.

[PTG1212]

Shraeder valves themselves are going to leak over time. They aren't spec'd for zero loss. I just had an issue recently with my a/c in my 2001 Windstar. No cold air and compressor cycling. I bought a 19oz can I think, 16oz R134a and 3 oz oil with a gauge on it. Cost was $20 at Advanced Auto parts. I found the low pressure side (r134a fitting won't fit on high pressure side).
Cap on low side also had an "L" on it. Must warn though, if by chance you could get the fitting on the high side you'd blow the can up in your hand. So although it's pretty idiot proof, it's still to be taken seriously. As soon as I started putting refrig in, compressor started working normally and air was cold. It's been over a month with no measureable loss of r134a, with my cheap gauge anyway.

Note that car is running with A/C on max and doors/windows open so compressor is running to draw in refrig. Put r134a in a bit of time and monitor gauge. Whole process takes 15 to 20 mins. You need to be continuously shaking can while putting in refrig to keep the oil mixed in. I think the product I bought also had some sealer in it, which simply expands rubber parts to prevent leaks. Read all the instructions before doing this if you haven't done it before.

All in all it was one of those, damn, I fixed my A/C for $20 moments. Gotta Love it.

[Gary1234]

My manual gives your A/C a normal working life of 7 years.
I'm sure to get a lot of posts claiming their systems have worked longer ... there are always some lucky folks out there.

[zorobabel]

Thank every body for your posts!
I think I'll try the refrig kit, I just have to get my hands on the 96-99 taurus manual, now ...

[MyTaurus8AChevy]

Originally Posted by zorobabel

I just have to get my hands on the 96-99 taurus manual, now ...

Do NOT get the Haynes or Chilton (same company makes both) manual. They are pretty much worthless. We returned ours and went to e-bay to buy a Ford CD manual for 15.00. AllData (owned by AutoZone) is another good option, but only available online.

[97TaurusGuy]

Originally Posted by MyTaurus8AChevy

Do NOT get the Haynes or Chilton (same company makes both) manual. They are pretty much worthless. We returned ours and went to e-bay to buy a Ford CD manual for 15.00. AllData (owned by AutoZone) is another good option, but only available online.

The Haynes/Chilton manuals are a very valuable tool when working on these cars. Lord knows I have used mine enough. I have a Ford CD also and find myself going back to the Haynes manual.

[Huney1]

Yeah, I had the same erratic idling and Rod told me to clean or replace the idle control valve. I cleaned and it runs fine now. Piece of cake, takes 15 minutes. Use the mass air flow sensore cleaner and let it sit a few minutes and the piston shaft will free up. I put a couple drops of thin spray lube on the shaft and it works fine.

Talking about AC's . . . Gary and I were previously discussing AC's and I came across this and thought I would share it.

"The A/C problem could be a bad Body Control Module (BCM) or Evaporator Temperature Sensor (ETS). The evaporator probe is a temperature sensing element located at the coldest point on the face of the evaporator. The evaporator temperature sensor prevents condensate water on the evaporator core from freezing and obstructing A/C system air flow. Output from the probe is sampled by the BCM. It is used to switch the A/C compressor clutch off before evaporator freeze up occurs. The clutch is switched off when the probe reaches 33.7 degrees. It is allowed to switch on when the probe temperature reaches 35.7degrees. Either one of these could be the cause of the A?C problem. The problem is worsened when the recirc or Max mode is on."

So now we know how and at what temp the temp sensor turns the compressor off. Seems like everytime I punch in here I learn something.

[Gary1234]

As far as I know, Ford uses an "orfice tube" to control icing on the evaporator. It's a small valve about 3 inches long located in the refrigerant line just before the evaporator ... it stops the evaporator pressure from reaching the freezing point.

An orfice tube system does not cycle to control evaporator freezing.