AC low side line at 73 lbs. preasure
 

Welp fellows here we go. After searching and reading Jon89 very informative thread https://www.jaguarforums.com/forum/s...e-start-36924/, this subject was not touched upon.

With my cheapie AC gauge on the low side line I am getting a reading of 73 lbs. which is way into the red section of the gauge. I have been in contact with 01stype30, he is very graciously going to let me borrow his newly aquired professional AC gauges and other tools to get proper high and low readings. Hopefully I will get them in the next couple of days.

Well heres our problem ever since we purchased the vehicle over 2 years ago there has been a green light oily film on the compressor, I clean it, it comes back slowly. Leak right(?) thats what I thought until I put the cheapie gauge on the low side. The AC has worked flawlessly over the years until now, I have never added any R 134A. It blows coldish air while driving, come to a stop *poof* warm air, start driving cools back down but not icy cold.

Back of my head is saying compressor time, although it makes no unusual noises and appears to kick on and off at idle with AC set at coldest setting with fan on high.

Thoughts???

If the oil's coming out then surely the gas has largely gone so it's in need of a top-up I'd think. Pressures (when on) at both ports will help. However, if it's leaking then curing the leak sounds #1 thing!

Proper gauges for high & low are quite cheap (even here!!).

Rick,

Raise your front end, remove your belly pan, get a mechanic's stethoscope, crawl under there, and listen to your compressor while the engine is running and the A/C is set to high. Remember that our compressor was diagnosed as faulty in May 2010. I didn't believe it initially because it sounded normal to me when I was standing over the engine bay. But when I crawled underneath the car and used the stethoscope, I could hear the piston sounding like a cement mixer inside the compressor. The A/C shop said that it was in the early stages of failure and that it would eventually give out. It may have lasted another couple of months or it may have failed within a week. The bottom line is that it was in the process of giving up the ghost and it could not cool the cabin any longer when the outside temps rose above 85 or 90 degrees. As you know from my thread, a new compressor solved our problem....

Other members here have had to replace their compressors during the last few months as the weather warmed up. While they don't fail on command like the IMT O-rings and DCCV, they do indeed fail. I haven't had a compressor go bad on me for 20 years until this one began to die late last spring, and that's why I had a hard time accepting the fact that it was indeed the compressor. It sure sounds as if yours is beginning to die as well....

I hope it is something less costly for you such as a worn O-ring causing a 134a leak. But I really suspect your compressor based on what you've said about it thus far. Good luck and keep us posted....

Remember that IF you do need a compressor that the Lincoln LS unit will be fine and is MUCH cheaper.
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Often the high pressure is related to the A/C system not being turned on. Check to see it is on and that the compressor is engaged and no blown fuses. As for the compressor I understand that a control valve operation is a problem.

Well guys, taking a crap shoot here, I just purchased a reman. compressor off ebay, just shy of $165.00 total it will be here friday.

REMAN AC COMPRESSOR 2000-2005 LINCOLN LS V6 3.0 | eBay

I will be picking up 01stype30 AC tools tomorrow and looks like a go for friday night fun!

Boy to highjack my own thread this has been a costly month in vehicle care:

Jaguar: Finally got around to ordering the rear tie rods (the ones with the visable bushings through the wheels) $200.00 ea., the rear sway bar bushing/bolts (visable only with rear tires off) $30.00 ea., 2 new Michelin Pilots $200.00 ea. (includes mounting and balancing), and an alignment. This work has not been done yet but will have to wait until next week.

$65.00 in rear ceramic brke pads 3 weeks ago.

Now AC compressor $165.00 and 3 cans of R134A $20.00ish a can (?)

Full write ups on above w/pics to come!

Escalade ESV: 2 weeks ago $400.00 in 2 rear shocks.

Well we are still smiling after all the above! Just think if we had to pay someone to do all the repairs :)

You should replace the 4way pressure switch if you are going to replace the compressor. That switch failed on my xk8 and had to drain the system to replace it, I hate to see you do it all over again.

Thanks Gus, you mean #5 in your above ACsystem pdf?

Yes! If it is not working it will prevent the compressor from kicking in.

I hear you, Rick. It's no fun shelling out cash for costly repairs. I don't mind routine maintenance but when expensive things break, I'm not a happy guy. 2011 has been a very quiet year thus far with nothing major failing on any of our vehicles. I'll do the rear brake pads on the S-Type this summer (probably with Vance's kind assistance), and I expect the factory batteries in both the S-Type and the Lexus SUV to give up their respective ghosts sometime later this year, probably as the weather turns cold again. Cheap as I am, I'm not replacing those batteries until the telltale signs of failure show up....

Good luck with the rebuilt compressor and the HVAC evacuation and recharge. Sounds like a busy weekend at Rick's Shade Tree Emporium and Gnome Ranch. Keep us posted....

Sorry I've been out of the loop Rick. I was in DC for two days for FDA compliance training.

Did you ever get high / low side pressure gauges setup on it yet?

Call me.

Take care,

George

I thought I would check in to see how the compressor replacement went. I hope all went well.

+1 How is it going?

A few things popped up. Long story but I haven't done anything to the vehicle yet, I have all the parts and equipment (thank you Nick) Sunday is now the day.

I will report.

Ok guys:

Ambient Temp: 70 degrees
Low Preasure: Fluctuating between 51 and 55 psi. (needle jerking)
High Preasure: 100 psi.

As car runs, the high preasure dropped from about 125 psi down to the current 100 psi, vehicle has been running for 10 minutes. AC on coldest setting, fan on high.

This should help. http://www.gusglikas.com/images/Auto...s/ACSystem.pdf I am not an expert but it seems that your pressure is low and if it is (based on the attached chart) the pressure switch will prevent the compressor from kicking in and allowing the A/C to work. My system did not work properly when I got the car and charging it fixed the problem.

Rick,

95% you are describing a compressor failure.

The low side seems a bit high, but the high side is definitely low, as if the compressor is not efficiently functioning. I think one of the internal compressor seals may be failing, as it seems like some of the high side pressure is bleeding back to the low side.

The jittery gauge also is indicative of a compressor that's seeing friction on a bearing.

I can walk you through the proper vaccum / recharge procedure. You have Nick's gauges and vacuum pump right?

Take care,

George

I agree George.

Thanks guys heres the new scoop.

The remanufactured compressor is wrong part, although it is listed as a 2005 Jaguar S Stype replacement AND Lincoln LS. I could make it work but for $165.00 (2nd day air included), we will wait for a replacement. I could use 1/2" spacers to make the reman work.

The good news is that it took longer to drop the belly pan than it did to drop the compressor. I spent 1/2 hour from jacking up the car to having compressor on work bench!

Ok I see I did not explain the difference in the 2 compressors below. In the yellow rectangle the bolt guides are about 4" long for the 3.0 litre engines. The red rectangle is for the V8 engines with the bolt guides at 3 1/2" long.


https://www.jaguarforums.com/forum/a...2&d=1305471716

Pull the cover off the old one and see if the "O" ring is part of the problem.

Just wondering: how did you conclude it had enough gas (R134a) in it?

The 50psi ish low pressure reading shows that there's a proper charge...

Take care,

George

Back in the fall, when this problem first really occured, I put a cheapie Auto Zone dial gauge on the low side and I had gotten a reading of 125 psi which would be an over charge. I have never put any refidgerant in it.

Of course I said the hell with it and fix it over the winter............well that was one fast winter! :)

Was the car running and the A/C on? That 125psi reading (albeit with the craptastic AutoZone gauge), seems WAY high, however when the system isn't running, the high and low side pressure equalizes.

I'll call you in a few mins,

Take care,

George

You mean it should be able to pump harder and result in a lower low-side pressure?

Sort of. If the car didn't have enough freon (under 25 psi) on the low pressure side, the compressor would not engage.

When the system is at rest, the low and high side pressures equalize. Normally you see around 40psi on the low side and 200-220psi on the high side when the compressor is engaged. In this case, the compressor is working BUT not at it's proper level - there is probably a failed seal between the low / high side causing some bleedback, so the low side never drops all the way to 40psi, and the high side never reaches where it needs to be for proper cooling. Does it have the proper level of charge, we don't know, but it has enough charge to diagnose the malfunction of the compressor.

If the compressor was ok, you would see the same 40psi on the low side, and probably 175ish pressures on the high side if the charge was low, but not full. The car would have cool, but not necessarily cold air, but it would be consistent.

The jitter on the gauge on the low side is the tell tale sign here. Obviously that is indicative of a leak, or a failed bearing in the compressor causing it to bleed pressure back to the low side.

Take care,

George

^^^Thanks for the above George^^^

Saga continues, yesterday George sent me an ebay link to a Jaguar OEM NEW compressor (Jaguar S-Type *NEW* A/C Compressor 2004-2007 | eBay)

Auction ended last night with my winning bid of $110.00 plus $15.00 shipping. Great Deal!!!

The wrong remanufactured will be shippped back with full refund!

Thanks for the heads up on the OEM George!!!!

Thanks George - but to play devil's advocate:

1. couldn't the low dropping to 50 (instead of 40) be "just what the jag does"?

2. couldn't the jitter be due to 50-ish being the lowest the jag goes and so it's repeatedly tripping?

I suppose these are the same as asking "how do you know that 40 (rather than 50) is the target low-side operating pressure for the jag's a/c"?

Just from practical experience / measuring my own car, 40psi low side, 210psi high, air cold enough to need a coat in the summer and cause condensation around the vents.

The jitter isn't the compressor going on / off... you would see spikes as the pressure started to equalize (more than +_ 4psi).

The PROPER way to charge a 134 system isn't by measuring pressure, but by measuring weight of the gas. This is done via a digital scale on the r134a tank. You can get CLOSE using premeasured cans, but it's not accurate. Fortunately there is a fair amount of variation allowed in terms of actual refrigerant quantity that the system will still operate under.

Take care,

George

I measured mine but can't find the readings!

(I do know how to check / hold vacuum / recharge / etc, thanks.)

This worked for me and it might help you and I hope it does.

http://www.gusglikas.com/images/Auto...s/ACSystem.pdf
http://www.gusglikas.com/images/Auto...or%20Codes.pdf

UPDATE:

Just received the new OEM compressor a few minutes ago. There is 1 difference between the new and old, I will post pics later, otherwise the new one has the 4" casing bolts rather than the 3 1/2".

I will be installing tonight.

WOW what a fast weekend! Little update, installed new compressor and with Georges help got it all charged up and yes Joyces Jag is now blowing ice cold again!

As mentioned earlier I have pics and I will do a complete write up. Really was a simple job on a 3.0 litre.

Very impressive, Rick. Did you have an A/C shop do the 134a charge, or did you do it yourself? Again, I'm impressed but not surprised. I think you can fix most anything that these vehicles can throw at you....

He vacuumed it down and charged it himself with a little help from his friends :icon_wink:

Take care,

George

Thanks for the additional input, George. I didn't read Rick's last post closely enough. I should have known that you were part of the solution!

My wife has me very busy with home repair projects lately. Not much time to spend here on the forum. And with our S-Type running perfectly throughout 2011 thus far, not many questions to pose, either. I guess that's a good thing....

Ok as mentioned earlier, I purchased a "new" OEM AC compressor off ebay for MYs 2003 through 2008, 3.0 litre. It does infact have a Jaguar sticker on it.

There is 1 big difference between the old and new. The new did not come with the black cover plate as seen in the pictures. I have taken a couple of different pics for everyone to see "whats behind door #1", and it isn't a goat :).

The small black cylinder on the left is a 2 part micro filter, in the 3rd picture.

Attachment 171964

Attachment 171965

Attachment 171966

Did you need
 

Rick:

I am curious- did you put the cover plate on the new one? I looked at AllDATA and they indicate you need a


Did you have any use for these items or did you work around it or is this a false positive.

Thanks

'Tom in Dallas
2005 S-Type 3.0 58K

Tom are talking about the compressor?