When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello friends, this is my first post; please look past my technical deficiencies. The summer heat in Arizona puts too much strain on my AC; just can't get the AC to blow cold enough. About to replace AC compressor. I will pay the freight if there is anything other than OEM compressor that has better output. Please let me know if there is something out there. Thank you! 1986 Cobalt Blue; does anyone know that other years Jaguar offered this color for Series III?
Some have used Sanden compressors; others have used a modern-day aluminum replacement for your original A6 compressor. Whether or not they provide colder air....I can't say. Let's hear what others have to say on that.
The GM/Harrison A6 compressor (if not faulty in some way; or simply worn out) is actually pretty darn good as far as ability to refrigerate air goes. The weakness, I think, comes from the rest of the system. Some people with older cars, including Jags, have had good results with upgraded condensers. Others might chime in on that as well. I have no direct experience.
Have you had a specialist check the system pressures? That would be a really good (and revealing) first step. And a specialist might have an idea on upgrades....especially in your neck of the woods.
The compressor generally isn't a problem, it's one of the biggest capacity automotive compressors ever made. The key to AC performance is getting rid of heat, and that means both the condenser and airflow over it needs to be perfect.
I'd start by taking out the radiator and making sure that there is no debris between it and the condenser, that is a very common problem with these cars. Then make sure the fan clutch is working as it should, and consider upgrading to the black V12 fan if you have not done so already. It's also important that the foam at the sides of the radiator is present to make sure that the air the fan is pulling is going through the radiator and condenser, not around it.
I'd probably also take the car to an AC shop and make sure you have a full charge of refrigerant, as low charge will cause low cooling. The compressor is the last part of the chain I'd be looking at, not the first.
R12 refrigerant conversion to R134a refrigerant is the problem.
R134a simply does not get cold enough especially if the a/c system was not designed for R134A refrigerant from scratch. The Series 3 system was designed for R12.
R12 is still manufactured and used but not available to consumers, only to government fleets and industrial use. But there are alternative refrigerants like Freeze12 and others that perform a lot better than R134a.
You need to find a shop that has the capability to convert from one refrigerant to another.
TRANSLATION: a shop that is able to use alternative refrigerants, not just R134a.
It's easy to DIY a replacement refrigerant and much cheaper. Use 22% iso-butane and the remainder propane. I use the Ronson butane, typically one can is enough and the rest propane to bring the pressures to where I want them.
The thing to remember about hydrocarbon refrigerants is they work at about a 3:1 ratio compared to R12, so if a system called for 3lbs of R12, you would use about 1 lb of hydrocarbons.
From a fully vacummed system, I first charge in the butane using a can tap, and also have a bucket of hot water close. As the butane boils and is pulled into the system it gets cold, so dunking the can in the hot water is to encourage the butane to boil and go into gas form to be taken into the system. Never charge liquid into the suction side of the compressor. Once the butane is in, you'll probably have 40-50 psi on the high side, then start charging in propane. I use the bottle from my bbq.
Depending on the outside temperature I'm usually aiming for 150-175psi high side and 25-30 psi low side. I can produce vent temperature just above freezing doing that. I always monitor vent temperatures as I'm charging, they will drop and then plateau at some point and the compressor should start cycling. If it runs continuously, then the system is still undercharged. A garden hose sprayed over the condensor will tell you a lot as the pressures should fall dramatically as the water takes the heat out. The vent temperatures shouldn't drop too much if all is working well and you have sufficient air flow across the condenser.
Picked up my new aluminum 134a four seasons compressor from Summit Racing. Had a foreign car shop convert it to 134a.
Lucky enough the fan & temp switches work fine. Attempts to rebuild the old A6 were unsuccessful. 77XJ12L with a BBC Chevy.
At the risk of starting another Incendiary Debate, Jose is RIGHT, R134a does NOT have the capability to transfer heat nearly as well as OEM CFC R-12 had. Hence the cabin cooling in our Elderly Jags is Seriously compromised when R-134a is merely added to the system.
(To make R-134 work as desired, one needs to change the condenser, the expansion valve, the compressor wouldn't hurt, change all the hoses to barrier hoses, and for best results, the evaporator. (In our Xj6s, that's a lot of fun.) So one rebuilds the entire system and R-134 might work as well as it does in any new car on the road today that was designed for it)
Putting R134a into a system designed for R-12 will almost always yield disappointing results (I actually had that professionally done once, on an old Chrysler, and regretted it Immediately!). Literature claimed 90% cooling compared to R-12, which is OK when dealing with 90F outside cooled down to 80F inside rather than the previous 70F, not too uncomfortable for most people. However, if it's let's say it's 120F outside, not out of reason in California or Arizona these days, cooled down to 92F inside, That is Not comfortable for most people, even in those places.
R-12 is well known for Ozone depleting properties, therefore banned the world over, as well it should be.
In search for an alternative for my old Chrysler I found HC-12a, Propane/Butane mix with some other stuff probably. As its cooling properties are superior to even our old beloved R-12, it requires far less to charge the system, relieving quite a lot of stress and lowering head pressure (perhaps making the system last longer?); only 6 ounces (170g) of HC-12a is equivalent to 15 ounces (425g) HFC 134a, and 17 ounces (480g) of CFC R-12.
I put Enviro-Safe brand, "Refrigerant for R-12 systems" in that old Chrysler, and it was stiff ******* cold again, so that one couldn't sit right in front of a vent when it was on Full Freeze. Therefore, when my Jag needed a little charge, Yep, that's what she has in her AC system.
No one sweats in my Jag when she's set to Full Cold!
Shivers maybe, gets a headache maybe, but No One sweats!
(';')
Jagboi64, Are you saying that the "Black" fan is more efficient at moving air than the White (now Yellow) ones? Ian
Yes, the blades are longer than the white ones and it has a smaller hub. On my XJS I can have the car idling and stand beside the passengers side door and feel a breeze of hot air coming out from the engine bay.
08-04-2022, 06:24 PM
Aftermarket AC compressor
