A/C worked fine here in HOT AZ for 15 years. A couple weeks ago it began to blow cool, not cold. Outside temp was 110 which it is often in summer here. When I got home & shut off car, the engine fan kept running or ~ 2 minutes. (That has not repeated since) Last time it did that was 2004 & I ended up needing a new T-Stat! Usually T-stats last at least 4 years & my last new one was 12-2011) Engine temp shows as normal, exactly in in the middle as typical of these cars. A/C blows colder when cruising with higher engine RPM vs. Idling which is typical when low on Freon.

Brought it in to dealer same day & SA said may just be low on Freon. Mechanic said found leak @ drier & needed new drier but, must wait for part. He added Freon & A/C was much better but still not as cold as b4, especially when idling. A few days later part arrived so had drier replaced/leak repaired.
A/C still not back cold @ idle as used to be for 15 years!
I bought thermometer to measure vent temps.

When cruising I can get icy cold, low 40s which is how it always used to blow. But when I sit & idle in traffic, temp climbs to ~55 degrees which is not cold enough to keep car cool in hot summers here & certainly NOT the way it has operated in the past.

I brought it back & they checked & said no leak (had added dye last time) but “somehow” was 4 oz low on Freon, their new Freon filling machine must have made an error.

A/C has not improved. 20 min after I picked up car, I tested by letting idle on my driveway for 15 min & never got below 55. I had rental XF & did same test & it blows 40-42 when idling.

Any ideas?

It is broken & dealer does not know how to fix it.

Thanks,

Steve

 

Perhaps you should take the vehicle to an air conditioning specialist shop.

There may also be a problem with the expansion valve if the refrigerant level is correct but the vent temperature is below specification. What are the gauge readings for both high and low sides?

 

Thanks for the reply,

I will ask the dealer SA to ask tech if he considered expansion valve problem & try to find out what the gauge readings were for both high & low sides.

I don’t know an A/C specialty shop that has more expertise in Jaguars than the dealer but maybe they don’t need to specifically know Jaguars.

 

The expansion valve is more work. But is time
For replacement. Fifteen years with cold AC is a great run. Replace valve and refill. This should get you back to 44 degrees.

 

most any AC shop can do the work. Someone that specializes just in AC will likely do better work for less. The reading will let you know if the compressor is failing or bad.
Expansion valves do eventually get blocked. Not easy to access though. Make sure
BOTH cooling fans are running. With only one, it will run a little warming. The splash
shield under the car is important for airflow while moving, but that isn't your problem




As far as the temp gauge being in the middle. It is more of an idiot light than an gauge. It just shows cold, warm, too hot. Get a cheap obd2 reader that works with your cell phone and you will get a actual temperature. 195 to 212 or more shows
the exact same on your gauge. There is a company called Real Gauge the makes you
gauge actually tell you something.

 

My post from 7-6-15 is either deleted or didn’t post for some reason. I’ll repost it here & then post separate update.

On 7-6-2015, I posted:

Car back at Jag dealer shop (3rd time for same A/C issue)
My SA brought out a temperature hand held device & we measured the vent temp (His device compared to my $10 Walmart thermometer) They were only 0.5 degree apart. He agreed much too warm idling (55-57) He said when it left the shop they had tested & was low 40s. So they will check to see if once again low on Freon & if not he mentioned; compressor, belt, clutch, etc.

Re Actual engine temp, I have an OBD-2 reader. How do I use it to read temp? Innova OBD2 3130

 

Update: Jag dealer had my car all week finally got it back Friday PM. They found a small, intermittent leak in the low side Schrader valve & replaced both Hi & Low side Schrader valves. Ambient temperature was cooler (98) when I picked it up late PM vs.
~ 105 early in the week. I brought my thermometer with me & drove my car around the corner of the building parking in front of the showroom & let it idle for 5 minutes checking temp & it did not get below 60 degrees! Very disappointed that it seemed unfixed & worse. I stayed there for another 10+ minutes & saw temp drop to 50. Better.
I drove home & during cruising the temp dropped to 38 degrees! Colder than b4 by a few degrees, although ambient temp was also significantly lower. When stopped @ light for 2 minutes, temp quickly rose to 44 which was better than the 55 as b4. As I watched it on the way home, it seemed to drop & maintain 38-41 cruising & w/in ~30 seconds when stopped @ light go up to 44 but no higher.
Probably unrelated but, during the drive home, I got a CEL Amber + a restricted performance message & rough idle. Later I read codes with OBD2 & PO303 & P1316 & strange Manufacture specific code C15AA which had no further info & was unable to replicate. So, I know I have misfire in Cylinder #3 & must replace yet another ignition coil. (This will be my 4th, all different ones) I ordered the part from Gaudin Jaguar & will do it ASAP. I think it must be a coincidence. I doubt either the bad coil & subsequent misfires affect A/C performance or that the tech somehow caused this issue. He probably didn’t experience either CEL or Rough idle/RP or surely would have told me. I just thought it strange to do it now just after picking it up from 4 days in the shop where they put 40 miles on the car.

Today, Saturday, I extensively tested my A/C. Ambient Temp = 102. Pulled out of garage after sitting all night & let idle with it set to coldest & recirc. During the ~ 5+ minutes in my driveway it quickly dropped to 60 degrees & then slowly kept dropping maybe 1/10 degree every 10 seconds till it reached ~52. I had enough sitting & thought 5 min long enough so, began to drive. In 2 min was @ 42 & another minute @ 41 & by 5 min later was 39! Reached long stoplight & in 2-3 min was @46. Drive & quickly down to 39 & shorter light up to 42. So, mostly stoplight idling increases vent temp 2-5 degrees. Longer I idle, higher temp goes. Continue driving with temp @ 39 & get home & sit idling in driveway. 1st minute goes from 39-44, 2nd min to 45, 3rd min to 46, 4th min to46.2 (slowing rate of increase!) 5th min 46.5. Wait additional 3 minutes & holding @ 46.4. End test.

So, is it fixed? 46 @ idle is not that bad. W/O a thermometer, would I even notice that increase during normal driving? If I cruise @ 39-40 most stoplights are 2-3 min so, will only rise to ~ 42-43. Plenty cold enough. I think my 2 loaners; XF & LR@ idled @ ~ 40-42 & did not increase as much as my Jag now does.

So, for anyone willing who has a thermometer to measure vent temperature:

1) start car that has been sitting in sun & just idle with A/C on low, can you reach low 40s? How long?

2) Drive at least 15 minutes till A/C vent temp is COLD (at least low 40s)- now stop & idle for 5 minutes or more. Does Vent Temp increase at all? If so, by how much?

3) When driving with normal A/C blowing low 40s & stop at average stoplight (2-3 min) does temp go up or stay the same?

 

the 50 degree temperature delta your describing is dam good for a r134 system. Personally i think anything over a 40 degree difference is very good especially for over 100 degree outside temps. Alot of the "time to cool" conditions your describing seem to be a function of condenser heat transfer. Often overlooked but very important is cleaning your condenser and radiator fins. 15 years of dirt will restrict airflow and affect the overall performance of your cooling and ac system. you would be surprised how some cars still work with the amount of dirt crammed in and in-between radiators. With out knowing AC pressures its tough to know exactly whats going on, but your system temps seem pretty good.

My ac system had an internally ruptured dryer shooting beads to the expansions valve and a low side high pressure leak around the evaporator (when you turned the system off, pressure would equalize/heat soak ~160 psi and the low side would leak)

 

The tech has decades of experience @ Jaguar per SA & worked on this for days so, I assume he tested the pressures on both sides & they were correct. As mentioned the 1st service re this issue he found leak & replaced drier.

I don’t know if he cleaned or checked the condenser & radiator fins. Are you referring to my main large radiator? If so, it looks clean.

 

What LOOKS clean and what is clean are two different things ;o)
It's the dirt that gets trapped between the two main radiators (at front of
vehicle) that can cause the problem.

Simplest way is to disconnect the main coolant radiator, remove from vehicle
(a simple job)....carefully flood through with a hose....DO NOT use a
narrow high pressure nozzle!!
This will damage and fold over the fins....remembering these radiators are all alloy.
Do the same for the a/c rad but flush it through from the engine side to
dislodge accumulated dirt.
Be very gentle with these as the fins are very easily bent.

The operation of your system sounds pretty normal.
The Nippon Denso system has a shut down mode built in when the temp reaches 40 deg C. (105 deg.F) or over to protect itself and the compressor.
If you avail yourself of the JTIS files in the archives, it will explain this.
You should also familiarise yourself with being able to read any stored codes
in the a/c system which can be accessed by a certain procedure.

When stopped for lengthy periods at stop lights, you should shift to neautral
to take the pressure off the transmission and heat transferal into the cooling system which will affect the a/c in such high ambient temps.

Do you run the a/c on auto or manual settings?
This system can also be affected by two other things....the temp sensor situated on centre front of dash near the screen (small round blue dome) and the cabin aspirator which is situated down near the remote boot opener
on left side in your case....this has a small fan and ducting built in which can become clogged with fluff.

 

Thanks for the reply.

I use Auto setting. For testing I have it set to lowest so fan is highest speed. Also Recirculation on. I have an OBD-2 reader which only reads Engine codes, cannot read any A/C codes unless I buy some other diagnostic equipment which would not be cost effective for me. I didn’t know about the temp sensor front center on dash but, I doubt very much it is defective since system runs & gets cold when cruising. Same for the cabin aspirator, although I would like to find that & check for any clogs. Maybe I’ll search for a photo or look under the left far end of my dashboard to see if I can remove something to check the fan & duct for obstructions. The main issue is why my system vent temp rises significantly when I stop & idle. It is much better than b4 since it only rises from 40 to 46 rather than rising to 55 as it had been doing. In fact, w/o measuring the vent temps, I may not have noticed any problem if it was always like this. Or perhaps my car & compressor being 15 years old does not perform as it did when new. I will see how it does over the next week or so. 107-108 next few days so, good testing ambient temperatures!

Do you know the answers to any of my temperature questions? Especially #2 or #3. I realize you may not have a thermometer to measure vent temperature.

1) start car that has been sitting in sun & just idle with A/C on low, can you reach low 40s? How long?

2) Drive at least 15 minutes till A/C vent temp is COLD (at least low 40s)- now stop & idle for 5 minutes or more. Does Vent Temp increase at all? If so, by how much?

3) When driving with normal A/C blowing low 40s & stop at average stoplight (2-3 min) does temp go up or stay the same?

 

download your manual
http://innova.com/Content/Support/Ma...al_3130c_E.pdf




Page 70 has LDM (Live Data Mode).
ECT is Engine Coolant Temperature.


Most AC problems aren't due to a high coolant temperature. If EVERYTHING else is perfect and the AC is still a little warm, I have
seen the following occur one of the radiator fans was not turning and the coolant was warmer. The condenser needs airflow and being by a hot radiator doesn't help the situation.

 

Yes, A/C still not working right! So far 3 trips to dealer & 4th tomorrow!
I started car & ran A/C @ idle. I saw BOTH radiator fans run. Upper one on passenger side & lower one on Driver side. A few days ago I ran Live Test @ idle with my OBD-2 & saw ECT slowly climb from ambient temp to 194 degrees F. The temp gauge hit center when temp reached 190, running an additional minute reached 194. So, my coolant & engine is not overheating & my gauge is fine.

The issue remains that @ idle A/C not cold enough. Currently today with ambient temps 105-107 F, I was getting vent temp ~55 if stop at long stoplight. Mostly cruising @ ~ 47. So, it has gotten WORSE since I picked it up last week. No longer cruising @ 38-39 F! So that suggests a leak they have failed to locate.
We'll see if I still have 1#, 8oz Freon as they said was capacity & that they put in last week. However, I did find this:
Jaguar Refrigerant and oil capacity charts || TechChoice Parts

Seems to indicate my 2000 Jaguar XJ8 takes 1#, 10.5 Oz rather than the 1# 8 Oz, Service Adviser SA had said.
In 2001 models, the capacity drops to 1# 8 oz.

Has it been under-filled all this time?

Jaguar (SA) says no, they used the correct capacity. If so, that means that web link has wrong data.

So far Jaguar has:
1) found leak in drier & replaced & filled with freon
2) found leak in Schrader valve & replaced both valves

I’m concerned they do not know how to fix it & will start throwing expensive parts at it (Compressor!) I’m certain they want to fix it.
Assuming it has been under-filled by 2.5 oz due to their tech error in reading specs, that doesn’t explain the loss of cooling over a week. But, does it explain the increase in vent temp when stop & idle at lights for 2-5 minutes. Whether or not it has lost Freon this past 10 days will be diagnostic, I think.

I’m not happy.

 

Sounds like the engine cooling system is doing well. It is good both fans are running.
That eliminates the non Freon system causes of a warm idling AC output temperature.
Do you know what the hi and low pressure readings are for the air conditioner?

 

The AC shop that hosts autoacforum.com is right in your backyard.

Arizon Mobile Air
7904 E Chaparral Rd #A110-608
Scottsdale, AZ 85250
TELEPHONE:
602-233-0090

 

Considering the temperature regulation system and the airflow, I would suggest you MIGHT have an air mix problem rather than a refrigerant problem. Do you have a way to measure the pipe temperature on the low side of the evaporator coil?

 

@Lear4, I do not know, the mechanic @ Jaguar surely does know & pressures are good/normal. If the hi & lo pressures were off or even questionable, he would have recommended some repair based on all my complaints & the time he has spent with it.

@Amphicar770, thanks for the reference, Yes, they are close to me & I see they sell parts online as well. I do not have the knowledge to repair my own A/C however, especially for a complicated problem that stumps dealer mechanics. I will keep them in mind though for the future. The forum is a good resource. & makes me wonder about my Fan clutch.
Automotive AC Information Forum - ACKITS.COM

@sparkenzap, No I do not know how to do this. Is this something that most experienced A/C techs would not routinely do when servicing an A/C?

My observations/conclusions to date:

Does not matter ambient temp 99-105 day or night! Does not matter if set to Lo/recirc vs 74/auto (as I had used for 15 years.)
What matters most is cruising vs stop & go & whenever stop @ light temp goes up 7-12 degrees! W/O stop & go traffic, I can be putting out 37-39 degree air in 5-10 minutes! @ light idling, w/in 30 seconds temp increases ~ 5 & by 2 minutes 7-12 degree increase. So have been idling & putting out 53 degree air when have been in stop & go traffic so only got down to mid to upper 40s. Must be no Freon leak or could not get to 37 degrees! In the next few weeks I will see if this is good enough to keep me comfortable when it is over 100-115 degrees out. The only other option seems to be to replace the compressor & may well not make much difference. So, maybe it is “fixed?”

I’d still like to hear from people with A/C that works just fine how much of a temperature increase you get when stop at a light for 2-5 minutes after cruising. I wonder if you cruise putting out 40 degree air & when stop & idle it only goes up to 42 & holds or does it go up much more as does mine.

 

Has the dealer tech acknowledged that there is a problem with the AC? Or is he just working because you sense a problem?

BTW, I think you are oversimplifying some of your parameters! For instance, the duct air temperature, which you post as 40-ish is highly dependent on airflow! If you had lots of 50 degree air, the car would be 50 inside. The AC system on a Jaguar XJ8 is temperature controlled, not load controlled as on older cars. The air temperature coming from the duct is adjusted via a heater core re-heat and some air mix dampers, but can only cool as much as the AC system can remove heat. Your arguments and the replies have all made the (usually correct) assumption that your problem is the systems lack of ability to remove heat, but since finding that problem has failed, you (the tech) should consider the other possibilities.

 

My SA is sympathetic & really wants to solve the problem. I am not sure if the tech now thinks there is a problem or not. I think they both think the “only” thing left to do is replace the compressor but, the tests the tech did show it is fine.

I have no doubt I am oversimplifying some parameters. I am not a mechanic & certainly not an A/C tech! My issue now, in layman's terms, is my system blows extremely cold when cruising (without stop & go.) But when I stop, even for 2 minutes, vent temp rises significantly & quickly. I doubt this is how the system is supposed to work & has worked for 15 years. But, I am not sure. As mentioned, I am wondering about my fan clutch & if the tech considered that.

Tomorrow & Wed it will be 112 degrees. A good test as to whether the system keeps me comfortable or not.

 

Iconoclast:
Ultimately, the temperature in the car is obviously what you care about. I believe my duct exit tem will rise about 5 degrees when I idle, but when the AC is in "Auto", the fan increases speed. Where I am heading with this is that it seems like your duct temperature is pretty cool, but apparently the inside of the car is getting too hot. Is that about right? Have you (or the tech) cleaned the temperature sensor- under the driver dash? Have you measured the cabin temp under different conditions? Has he checked the heater valve, which I am pretty sure is controlled for re-heat even in AC mode?