Jag News. Good, Bad, and Ugly. [UPDATED]

"Akio Ohtori - RIP Oppo" (akioohtori)
10/01/2020 at 16:00 • Filed to: The Hot Mess

[UPDATE] The more I’ve been digging into this the less I’m worried. As people have rightly pointed out, a stiff compressor shouldn’t be blowing a clutch fuse (probably). Also I was incorrect what else was on that circuit. The cooling fans also live there and that seems like a more likely culprit. I’m going to do some investigation later but I’ve got too much other shit to deal with right now.

Triple post day! That can’t be good.

Yesterday I dropped the Jag off at the AC place to get the problem diagnosed. My initial suspicion based on the failure (sudden stop, bad smell) was that either the climate module or a coolant hose bursting.

Good news is it wasn’t either of those. It was the fuse for the compressor clutch. They replaced the fuse and the AC is working again!

Bad news is the shop is speculating that means the compressor is packing up.

Ugly news is they want $3,600 to fix it.

So... lets unpack that a l ittle.

First off, the compressor clutch fuse blew. I agree they shouldn’t do that and it is likely a symptom of something bad happening. Before condemning the compressor, what else is on that fuse?

The auxiliary water pump! (Maybe?*)

Unfortunately, that is unlikely to be the cause as (A) the aux pump is only supposed to run when the heat is on, which it was not, and (B) I replaced that pump recently.

Technically B actually gives me some hope if the pump was bum or I didn’t purge the system correctly? Long shot.

*The maybe is because that fuse is listed as “air compressor clutch” which seems correct, but other places the AC is listed as “air conditioning clutch” so who the fuck knows.

Ok... so there is that.

Also looks like that fuse feeds a relay that feeds the clutch, so I’d want to check that relay out too. The relay is in the engine compartment in “smell-o-vision” range, so maybe....?

And what of that smell? Everyone seems to think it was the belt slipping. I feel like with a new belt and tensioner I would have heard something? Hard to say but I dunno.

So what now?

In my guts I don’t buy the “gradual compressor fail”. I do trust the AC guys, but also have my worries about that part...

Seems like my options are:

Pay $3,600 for the full replacement - Literally no way

Pay $2,200 for replacing the compressor and drier but not the expansion valve

Pay $1,250 for the labor and supply my own part (have not cleared this with the shop)

Pay $300 for the parts and do the work myself

Sell the car and don’t disclose the problem

Sell the car and do disclose the problem

Of these, 3-6 are the most likely. I know a lot on Oppo (rightly) think it is time for 5 or 6 and I’m not far from it myself. Make no mistake... this car is leaving my stable. But when? And how?

The cost difference between 1 and 2 is down to the expansion valve, which lives on the condenser and requires 11 hours of labor to replace. The shop’s stance is it needs to be done if there are metal flakes in the oil and they have no way or knowing that without dropping the compressor. (Unclear if that is true.)

Option 4 is... well frankly looks like a pain but not a massive pain. The biggest problem, apparently, is the need to remove an engine mount to get the compressor low enough to remove. This would require some special tools I do not have but that I am willing to buy.

Easy right?

I’m not really sure what to do on this one and am going to have to give it some thought.

A thing I seent, for your time.

DISCUSSION (19)

Highlander-Datsuns are Forever > Akio Ohtori - RIP Oppo
10/01/2020 at 16:04

Sell it and state: “ AC not working, just needs a charge.”

Akio Ohtori - RIP Oppo > Highlander-Datsuns are Forever
10/01/2020 at 16:06

Hey the AC is working though, so.... “AC works grate!”

WasGTIthenGTOthenNOVAnowbacktoGTI > Akio Ohtori - RIP Oppo
10/01/2020 at 16:07

AC deosn’t ain’t not work grate.

66P1800inpieces > Akio Ohtori - RIP Oppo
10/01/2020 at 16:07

Option #4, and quick to avoid filling the system with glitter. Either way make sure to replace the condenser and flush out the evaporator as best as possible. Some auto places now rent vacuum pumps so you can make sure everything is correct, then take to a place and have them fill it for $200 or fill it yourself if you think you can get the weight right.

WasGTIthenGTOthenNOVAnowbacktoGTI > Akio Ohtori - RIP Oppo
10/01/2020 at 16:07

TheBloody, Oppositelock lives on in our shitposts. > Akio Ohtori - RIP Oppo
10/01/2020 at 16:17

I’d replace fuse, see if it pops again and if it does sell it or replace it yourself if you have the time and inclination. Dumping that amount of money into it doesn’t seem like the best option. Hell, that’s a sizable chunk of money that can go towards a XJ-R... Not that I’m trying to give you bad ideas or anything...

someassemblyrequired > Akio Ohtori - RIP Oppo
10/01/2020 at 16:18

To be honest, I’d probably have a whack at swapping the compressor & drier. They’re relatively cheap parts, and what’s the worst than can happen .

A lot was accessible through the scuttle on my X, but I suspect access to the expansion valve is a dash out repair on the S. It’s not an expensive part though.

Sovande > Akio Ohtori - RIP Oppo
10/01/2020 at 16:29

How much is the fuse? Just buy a box o f those and swap them in as needed.

MM54 > Akio Ohtori - RIP Oppo
10/01/2020 at 16:48

4 or 6. Leaning towards 6 - it seems like you’ve really fallen out with the jag.

Chariotoflove > Akio Ohtori - RIP Oppo
10/01/2020 at 16:55

What I got from all that is that it’s good you’re getting into cycling.

RacinBob > Akio Ohtori - RIP Oppo
10/01/2020 at 17:16

Wait? How does a Stiff” compressor result in more current pull by the clutch? That makes no sense. Whether the engine is on or off, whether the compressor can spin or not, the clutch pulls the same current. Maybe the clutch is failing but not the compressor....

haveacarortwoorthree2 > Akio Ohtori - RIP Oppo
10/01/2020 at 17:35

AC ran when parked.

RacinBob > Akio Ohtori - RIP Oppo
10/01/2020 at 17:52

PS, I always look first at the last thing you changed. Any chance you can unplug the aux pump and see if it still blows fuses?

MiniGTI - now with XJ6 > Akio Ohtori - RIP Oppo
10/01/2020 at 21:37

The compressor in my 85 XJ6 sounds like it could pack up any minute and yet it keeps working. I don’t even know how the AC still works at all. I did have to repair some of the clutch wiring at one point probably because of previous owners not being careful with it.

I also think someone might have converted it to R134 as it appears to have r134 service ports.

pip bip - choose Corrour > Akio Ohtori - RIP Oppo
10/02/2020 at 03:45

can you find a used compressor?

AMGtech - now with more recalls! > Akio Ohtori - RIP Oppo
10/02/2020 at 10:04

Was this a Jag specialty shop? Or just AC general shop? If the latter it’s probably worthwhile to get it checked out by someone who works on these all the time.

On some cars you can replace the clutch separately from the compressor. Depending on how yours is actually setup, the clutch circuitry (if it even uses a clutch at all) probably wouldn’t be affected by internal mechanical issues in the compressor, which would point to shorted clutch windings or chafed wiring.

They are correct about the expansion valve. But if the compressor is working, not seized, then the expansion valve is probably fine.

Improper bleed on your coolant pump cannot cause this. Those pumps draw less current when not pumping coolant, i.e. when there is air in the system. An internal short in the pump could cause it, or damaged wiring.

Can you describe the smell?

Akio Ohtori - RIP Oppo > AMGtech - now with more recalls!
10/02/2020 at 11:03

Yeah the more I dig into it the less I’m worried about the whole system being a ticking, expensive, time bomb . Worst case it is the clutch, which can be replace separately but at 120k miles for the effort required to take the compressor out I’d go ahead and replace it anyway.

But yes, I am warming up to a faulty diagnosis on the clutch. I’ll be digging into the wiring schematics soon, but that 10A fuse also runs the cooling fans (or, more likely, fan relay, unclear). Additionally it isn’t clear to me how the compressor clutch relay enters into the equation.

Either way, I’m going to take some current readings (hooray being an EE, I guess) and see if I can find some specs to compare them too. Current speculation is either the cooling fans, compressor clutch, or both are slightly tired are overloading the 10A fuse but, again, I don’t have detailed schematics yet and haven’t had time to dig into the ones I do have.

AMGtech - now with more recalls! > Akio Ohtori - RIP Oppo
10/02/2020 at 13:48

There’s no way the cooling fans are run off of a 10a fuse that also powers other things, so it’s got to be for the relay, and I would be surprised if a relay was blowing the fuse.

Some compressor clutches can be replaced without removing the compressor. Just FYI in case you didn’t know.

Akio Ohtori - RIP Oppo > AMGtech - now with more recalls!
10/02/2020 at 14:28

Gotcha and yeah seems like a lot of work for a little 10A, hence why more investigation is required. If the fuse that is blowing is only operating the relay coil then it would make even less sense for the compressor to be the issue. Need to trace out the madness for sure and see what, exactly, that fuse is powering. I wouldn’t put it past a Jaguar branded relay coil to fail in such a way that it sometimes works and sometimes blows a fuse!

Makes sense you could do the clutch on some cars without removing the compressor, but not this one. Sucker is buried in there. You actually have to partially drop the engine to get at it because of course you do.