For some time I have observed that when I turn on the A/C compressor, the motor runs rough and shakes along with a pulsing groaning/grinding noise. When I turn off the A/C button, after a few moments it goes away. This is worse when in gear but still occurs even when out of gear. Some days are worse than others and sometimes feels like it is going to stall. Dealer thought it might be related to the throttle body but since that was replaced under warranty, the problem persists. The Jag dealer is at a loss for ideas, as am I.

Help?

 

Don't turn it on again, the compressor is obviously grenading internally, you will need a new one. If you let it blow, you will be replacing more stuff including the orfice plus flushing it all out.

 

Gosh, how can a dealer be stumped? Someone who knows Jags needs to open a Jag only repair facility right next door to that dealer and put up a sign that says "Bring your Jaguar here and it will leave repaired".

How hard can it be? These cars aren't rockets! SHEESH.

 

Unless youre over 50k or early production sale date 08, should still be under warranty. I would vote compressor too.

 

There has to be more to this story. WOW!!!

 

Brutal, I believe Jahummer's referring to his 05 Super V8 and not his XK. He would post XK woes in the XK forum, and certainly the dealership would be honoring an existing warranty.

Nope, the dealer is clueless. How many techs must they have? I am imagining a crowd of knuckle-dragging mouth-breathers standing around Jahummer's idling Super saying "yep, sure is a funky noise. I wonder what it is?"

Unbelievable. I'm not a pro, but I can fix cars. I am believing right now that my skills in auto mechanics outpace those Jag technicians at that dealership in FL. What's wrong with the world?

 

The car is under warranty until 100K miles. I am not convinced it is the compressor. The AC works just fine. I believe they have 6 techs and most of them have been there more than 5 years.

I do have the Jag diag printout and there are a lot of DTCs, some of which they fixed. The rest the service writer said were of no consequence. One of the DTCs says P0308 cylinder 8 misfire, B1671 battery module voltage out of range, B1676 battery voltage out of range, U1262 SCP communications bus fault, U2509 torque reduction request can not be fulfilled by the engine management system, P1316 misfire rate excess emissions.

They also could find no vacuum leaks.

 

lol, well I troll todays posts and seldom know what section Im in. Doesnt really matter much to me. I just looked at his first car in sig and stopped there. You know how us knuckle draggers are
Maybe its one of those dealers that makes the techs buy parts that they order if not the problem, then nobody orders anything unless absolutly sure.
I believe in useing knowledge, experiance, and the abilty to be comfortable knowing if I make a mistake my boss is not gonna make me buy the part....We do make mistakes, but its never a big issue, and without the abilty to be able to sometime diagnose with parts substitution you end up spending a ton of time that could be cut down to minutes instead of hours.
Now swapping a ac compressor is not a short process, but based on info given. that was my first thought and where I would go first.

 

Which is why I said there must be more to this story!

 

I was curious why there was no mention of al the DTC's in the orignal post? It's hard enough to help someone online but without all the information, its much harder. If I want help, I put up everything I can think of to save time and get better results.
Just looking at them, they don't seem related to your symptoms.
Just pull the serpentine belt and see if the noise stops. That's the test I would use to see if it's the compressor. You could also listen to the compressor with a stethoscope to see if the noise is inside it.
By the way, those U DTC's are pretty critical, I am surprised you are not in limp mode with the U2509 code, as this is what the tranny uses to help select shift points. If your service writer told you these codes were of no consequence, he was wrong!

 

By the way, the U1262 code is a problem in the audio control module, start looking there for the SCP network fault.

 

Brutal. I would never put you in that class, and I was being VERY sarcastic. I hope you didn't take any offense. I have known mechanics, without any sarcasm or exaggeration, who are smarter, more educated and refined than I.

I also know that you and MK 82 are what I would call "real mechanics", people who aren't afraid to get in there and DO something, like remove a part to inspect it, for instance. I think you're probably right. These guys are so accustomed through training and directives to simply rely on codes and diagnostic tests to tell them how to proceed that they have put their senses and hunches away in some dark corner.

 

Trav, no offense and i speak sarcasm as a second(sometimes first language) that why i used 2 smiley faces.
Its not always directives or training. But more insurance policies. Think insurance and the medical field. Insurance companies(medical, ext. Car warranties etc) all want to give consumers peace of mind etc... But they want to control all the costs. I go to the dr. And a normal test might be say $300, insurance pays $18. I meen really? That wouldnt pay for the paperwork to be done. I come from a family of doctors and i have personally lost 2 of my own doctors that closed their practices due to inability to deal with the insurance costs, reductions in pay and having to have 1 or 2 people just to file and deal with the claims process. Not only are you gonna short pay me, but your gonna make me hire a person just to jump through your flaming hoops too?
Techs are in the same boat many times. Maybe not in this case, but as an example. I just had a 07xk convertible that was jamming, checked for codes are there was none. Had to diagnose old school and check all the ram switch and electrical functions. I spent alittle over and hour to diag a bad switch on a ram. The extended warranty only would pay me .2(12 minutes to diag and no more. And then the repair so i ended up losing an hour of my time for no pay. This kind of stuff goes on all the time. People wonder why good techs leave? The more you know the less you end up earning in annual income. Yes you may get more per hour. But less hours earned with harder non paying work than the guy that is newer, less skilled making less per hour but doing the easier work., and therefore making alot more hours.
So how enthused would you be knowing that to fix an issue it may take you "x" and get paid "d". More and more people buy ext warranties which is good. You get more work covered and done. But its a 2 sided sword. Just to diagnose a air suspension problem i get alot less time out of warranty than in and the manufacturer always pays less time....anyway i do have work i need to work on now behind me so later.............

 

I did not mention them at first because as you noticed Jaguar said they were not important.

I did try something else somewhat crude, I felt around the engi e compartment while it was running and noted the greatest amou t of vibration was coming from the rear of the motor.

 

My last post on the matter but I just can't understand how the source would be so difficult to find.

 

well said Brutal, and confirming of my take-away suspicions. A sad day indeed.

Guess the indies are well-positioned, theoretically, to take advantage of this grim reality regarding the company stores. Or has this endemic reality hit the indie repair shop as well?

 

Well Trav thats another issue too. You buy an ext warranty and many indies wont work with them for some of the same resons as Doctors. you have to have someone sit on the phone to call and get approval, wait for inspections, get your times cut and no diag time many time(what you think we LAY HANDS to diag)
So they dont deal with them. The ones that do around here are $90+ an hour for all the extra paper work and staff needed(just shy of dealer drive fees without the same training and car washes )
You know we have some of the best Doctors and Hospitals in the world, but you cant cut everything to the bone and maintain the same level of service, and skill. If you poll HONEST doctors many got into the field for the $$$. or maybe as my dad always says. "they would be veternarians, less pay, have to know male and female of more than 1 species, your patients don't tell you where it hurts or for how long, less pay. your patients bite, its harder to get in Vet schools and fewer of them. The good news is though, IF you flunk out of Vet school, many still go into the medical field and become human Doctors
Yes my dads a vet, my uncles are patologists and Ear nose and throat specialists. Ive been lsitening to this retoric all my life.
oopps I almost forgot, you have to pay in many cases as a human DR( depending on field) over a $100k a yr in malpratice and other insurances. dont get me sarted on our politicians or lawyers in this either...night

 

Interesting you would bring docs up....I always thought of doctors as skin mechanics.

I worked as a grease monkey in a fleet maintenance garage in High School, as I got better around the shop, the next year, I asked to be put on commission as a mechanic...no techs in 1966. My pay dropped to about nothing! I made more sweeping up.

 

I got my first summer job at 17 as a sweeper and gopher. Graduated to front end mechanic and aligner. Did alignments, brake jobs, and front end rebuilds on 18 wheeler.

All for $1.25/Hr. I took home $40 per week. Thought I was rich. Gave me an incentive to finish College.

 

And some suggestions to help the Jag dealer on the diagnosis?

What should I tell them about the DTCs?