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Getting my 2000 xk8 back on the road again after an engine exchange.
The AC is not holding a charge. First time I vacuumed the system and then charged it with the proper amount of R134A.
I added UV dye when charging the system. It blew cool air for only a couple of days. I topped off the system last weekend. It blew cold for that day. The car sat all week and is now blowing hot air again.
I used the UV flashlight and goggles but I can't find a leak anywhere. The only thing I haven't check is the evaporator. Is it prone to failure? Is there a way to check it out without tearing the dash apart. I haven't worked in this area so I don't know how hard it is to get to.
It's buried under everything, even the heater core. I have not had to dig into the Jag system yet, and hope not to, but I have replaced the heater core in a Maserati 4200, and it's a full 20 hour project requiring removal of the dash and center console. The XK8 looks very similar.
FWIW, if you pop out the center wood veneer, remove the screws for the underlying grill, and then manage to open the face flap, a mechanics mirror will let you see inside the heater box. You will see what you can see, unsure if it is the evaporator or the heater core, but with a leak that big, there might be visible dye. This is a 5 min job. Really.
Other option is to somehow fish the wheel wells for these A/C drains, and check if there is enough access to somehow detect any dye. Maybe even shove a paper towel, or a pipe cleaner and see it it comes out with something detectable.
Might have to do both, and put the UV light through the face vent and inspect through the drain holes. I believe there are cheap inspection cameras these days that could help bring visibility to hard-to-reach areas. I suppose there are creative uses of a mobile device camera that could help too.
Before any of that, it seems a common problem is the recharge valve core itself. Hard to see how you would have missed that I suppose.
Sure hope it is all negative because it looks like a bear of a job to open all that up. OTOH, perfect time to cleanup all this aging and likely crud-soaked foam, mildew, pollen and other allergens from that area, as pretty much none of us have a pollen filter.
Hope it's something accessible that you've disturbed with the engine swop. The dye is very easy to see with a UV torch:- the front of my engine compartment looked like a ghost train when the compressor front seal failed and spattered refrigerant everywhere.
Thanks RJ, fmertz, and Michael.
I too thought it would be one of the connections from the engine swap. The AC did work before the engine exchange. I took the lines off the engine that came out of the car and put them on the replacement engine.
After the first time I check all the lines from the top and underneath with the car on the lift. Nothing. I took the cover off of the ports and I could see the residue illuminated. This also confirmed that my light and goggles were working. The ports were not leaking because there was no illumination around the caps. I took the cover off the top of the radiator and checked all around the condenser, nothing. This is why I'm thinking somewhere between the firewall and the evaporator on the cabin side.
I read a post by Addicted2boost on the x308 site. He has pics of his entire dash out and needed to loosen the steering wheel. I'm sure we have less room on an x100.
Checking the website out I found references to using a freon sniffer. I did a web search and Harbor Freight has one for $65. I will get one tomorrow and see if I can't isolate the leak. If I come up empty handed I will find a local AC shop and have them diagnose it for me. I willing to spend a few bucks to make sure it's the evaporator before I tear the dash apart.
My 66 Mustang Fastback doesn't have AC and never will. I do the old 65MPH with the windows down to cool off. I think we are all getting spoiled with our AC, power locks and windows, ABS, cruise control, etc. I love that car because it is simple and good looking, just like me.( Except for the good looking part)
My 66 Mustang Fastback doesn't have AC and never will. I do the old 65MPH with the windows down to cool off. I think we are all getting spoiled with our AC, power locks and windows, ABS, cruise control, etc.
A friend of mine had a dark metallic green '66 Fastback back in the late 70s. It had professionally flared wheel arches and side exhausts (were they Thrush or something like that?). Gorgeous car and boy, did it sound good in the tunnel here
I think it's partly we're spoiled, but also we want things that are fitted to work properly, so OCD...
I took fmertz advice and took the center cover off then removed the vent and 2 screws holding a screen in. This gave me access to the top of the heater/evaporator cores. Using the UV light and goggles I got nothing.
I purchased the refrigerant leak detector from Harbor Freight. It was on sale today for members for $50. I checked all pipes and fittings in the engine compartment and got no readings. I got a slight reading from the top of the heater core, I think the heater core is the first core. I didn't get anything when putting the probe between the 2 cores. I recharged the system again. No reading at first with the fan on low. When I turn the fan to high I got a good reading of refrigerant gas. Turn the fan to low and no reading again.
My guess the evaporator has a leak on the far side, which I have no access to, and when the fan is on high the gas blows through the coils.
While I have this apart do you think it is a good idea to do the heater core at the same time?
I don't recall any threads on heater core failure and I would be worried that replacements , even supposed OEM, might not be be as good as the original. But since you have to remove it and you won't want to go there again, probably a good idea.
I talked to my son yesterday who is a Diesel Tech in Hickory. He is also a certified AC tech. He said that it is possible that the fan on high could be giving me a false reading. If you blow into the end of the the sniffer it will sound the alarm.
He is comming to visit in little over than a week. He said he will help me dianose and do the repair when he is here. If it is the evaporator I will probably do most of the work, I don't want him spending his time off on this big of a job.
I been doing a search and can't find a proceedure to remove the dash to get the evaporator out. It looks to me like it needs to come out through the top of the dash. If any of you know here I can find the procedure it would be appreciated.
I've done the evaporator on my XK8 - it wasn't actually too bad to get to, certainly easier than when I did the heater core on a Subaru that I had. There are quite a few connectors to unplug and steering wheel and passenger airbag to remove, but there's nothing remotely difficult and the instructions in the workshop manual are spot on.
Do make sure that the system is properly evacuated before disconnecting - don't make the mistake of thinking that just because the system doesn't work that the gas has all escaped, otherwise you could unwittingly undo a connection and get covered in the UV dye, making you look like you'd just robbed a security van. Don't ask how I know.
I've done the evaporator on my XK8 - it wasn't actually too bad to get to, certainly easier than when I did the heater core on a Subaru that I had. There are quite a few connectors to unplug and steering wheel and passenger airbag to remove, but there's nothing remotely difficult and the instructions in the workshop manual are spot on.
Do make sure that the system is properly evacuated before disconnecting - don't make the mistake of thinking that just because the system doesn't work that the gas has all escaped, otherwise you could unwittingly undo a connection and get covered in the UV dye, making you look like you'd just robbed a security van. Don't ask how I know.
Do you have any pictures? (Of the guy who looked like he robbed a security van)🤢
Found the source of the leak today. I put the car on the lift so I can look above and below for the leak. I recharged the system again. Looked above and couldn't find anything. Raised the car so I could look underneath the car. All this time I have the AC on and the car running. As I lift it up I can see a puddle of green refrigerant on the ground and it is comming from above the engine side of the bellhousing. I found the leak on right side of the throttle body. Before when I checked for the leak it was with the AC off and it was so small I missed it. With the AC on I could see it oosing from the line. It is the line from the firewall to the compressor.
. I don't think this will be easy either, the way it goes along side of the engine. If any of you have done this any pointers will be appreciated.
I'm pretty sure all the X100s have the two-piece pipe/hose and you likely just need the HOSE (MJA7310AG) with the flexible section. (some of the X308 sedans have a one-piece line, not fun)
Get a new 'O'ring as well.
The pipe with the 'muffler' (all aluminum) is more difficult to access and replace.
Bob,
This 2000 xk8 has a one piece hose. The engine that I just put in this car has a one piece hose. I have a 97 xk8 donor and it has a 2 piece hose. Can I try to find a 2 piece hose and use it to replace this one piece hose. I prefer to buy new than to try to get the one off my 97 donor.
Thanks,
Bob
BobRoy,
I know we're talking different beasts as mine is '98, although it also has a two-piece pipe, probably replaced on a motor change.
My understanding is that this pipe was split into two at some point during production. I've read about this change in relation to something else, but I don't recall where - I must make better notes. It then went back to a single-piece (C2N1700) on the late cars, although I've no idea if that will retro-fit.
On the XJ, it was done to cure a whistling noise when the AC was turned on:- I wonder if this was extended across to the XK? Bob (motorcarman) posted a TSB. See his post here: https://www.jaguarforums.com/forum/x...6/#post1522323
The parts you will need are MJA7312CB (the bit with the silencer) and MJA7310AG. The latter has been superseded by MJA7310AH, but showing as unavailable on Heritage, although Jagbits lists it.
Bad news is they're effing expensive. Not sure how easy it will be to remove the lower section to the compressor, as I had the LHS cat out of the way at the time, and I didn't have to deal with the added obstruction of the steering rack.
This is one of the A/C lines that I have to replace on my '06; I was told by the A/C shop I took it to that all lines had signs of leaking at the crimp joint. Purchased all new lines through DCR Motorsports. Have not even attempted this little ole task yet, as I am hoping to get through Summer. Doubt that is going to happen as I found a nice green spot on the garage floor the other day.
The '06 has the one piece line between firewall and compressor with the inline muffler, new line is the same. Not going to be fun at all getting the new line in....or even the old line out. There is some type of line clamp on the end of the left cylinder head or perhaps on the engine block that I have not been able to even see yet.
BobRoy...good luck and if you come-across some hints, or "should have done"...appreciate it if you would send them my way.
07-03-2021, 06:53 PM
AC Leak?
