Hey there.

Got this new to me jag 2011 xfr not even a week ago and all has been well driving it every day except yesterday.

Taking it to town (30min drive) about 10 minutes in low battery warning came on along with a bunch of faults, low transmission etc.

Figured alternator despite old owner saying alternator & battery are new... turned around and went home not wanting to get stranded.

Once home put it on ramps and checked alternator connection and battery connection in trunk, all seems good and new. Hooked up my battery charger and did an alternator test which checked out good, battery cables tight.
pushed all fuses under hood and all seemed seated well.

Started the car all warnings were gone, was reading battery voltage through my obd2 and said 14.6-14.8 so back to town i went knowing those things aren't the issue.

Once in town low fuel warning came on and i shut off car as i was at my destination.
Once started back up all appeared normal, then on way home low fuel warning again and no fuel gauge reading- kept driving, and eventually start working again... battery light never came back on in the 1hr trip and some town driving but something is going on...

Any hints please? Not sure where the ecu connector is maybe check the plug? Or what else could it be throwing those random warnings.

 

Did a battery load test and it checks out fine too... then tested alternator again under load and it charges battery.

Crawled under car again to have a closer look at alternator, some oil around it... did more research and read upper timing cover gasket leak possibly? Which fails alternators... but why would it check out fine during test?

Called an auto shop and getting a quote to have that fixed, possibly replace alternator aswell... while down there might aswell do supercharger coupler, service sc w. New oil and snout, upgrade coolant pipes to metal & change chains/guides... probably going to need alot of vaseline for this one... but eliminate all issues of this engine in 1 go? Thoughts?

 

Sat in driveway hooked up code reader and voltage dropped to less than 10V on battery in a matter of 2minutes, all lights came on again. Shut it off and now doesn't start... charging battery.

Had this car for 6 days, drove it home 6 hours without a hiccup & now all of a sudden it just acts up.

 

So digging into this deeper! More findings... looks like the oil leak is from the 'brake booster (oring?)', does someone have the part number please?

Also checked connections on alternator which are all tight. Sure alternator has a bit of oil on it, but the brushes look quite clean overall so don't think that be the big issue?

However, I've been charging battery and it seems to only get up to 12.4v fully charged, dead cell?

Even just starting the car in driveway now the low battery light comes on and the voltage just drops drastically on it... fried battery? Or faulty alternator that fried it, as when i was driving the ecu had a constant 14.6-14.8V on it which makes me believe it overcharged constantly? Get new battery and alternator? And what is the part number of that o-ring or fitting please.

 

Common problem and you need a new battery. Swap it out and see what you got. Use the right battery. Your new to Jaguar so be aware that batteries are just something you will go thru as Jaguars are very sensitive to battery problems.

That is the gear driven vacuum pump and that's also a common oil leak. There are some O-rings that you need to replace. Fairly simple but drain the engine oil unless you can raise the front of the car on ramps as you will lose some engine oil if you remove the pump from the engine. Yours is leaking from the vacuum tubing but your in there so I would also swap the big O-ring that goes between the vacuum pump and the block too. It would be a good time to repair that when you do an oil change.

Another note? It looks like you have cam covers leaking oil down onto the alternator. This can and will take out your alternator so get it fixed. Yours does not look too bad at the moment.
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Thanks a ton for the reply, I do have ramps and will pickup an o ring kit later today to atleast fix the main leak by the stem for now, it's really dripping there!

I asked previous owner again yesterday, he mentioned he replaced battery with a brand new one 6 months ago and refurbished the alternator...

I had a brand new battery from my pickup truck that i tried, but still doesn't seem to get a voltage increase when hooked up/idling... will test voltage output later today right off of alternator and see if i might have a weak connection inbetween before ordering a new alt... got quoted 480 CAD yesterday & a battery I think 290 CAD.

alternator doesn't look too bad, not totally soaked in oil you're right, but who knows it being remanufactured...

Definitely car needs some work, bummer as I only had it 7 days today and didn't even put 1000kms on it yet.

Alao would weak battery/ failing alternator act up fuel sensor? Showing no fuel & then just coming back on it's own? Bunch of electrical issues in 1 day that i didn't have for 5 days...

 

Well that's the weird thing about these late model Jaguars. Yes that could very well be your problem. I did not believe it for a long time but the wide array of problems that have simply disappeared with a new battery is huge. So a default on this list is ALWAYS make sure the battery is 100% first regardless of how old it is. Can you post what battery was used and the brand and rating?

Ignore the alternator right now and check if the cam covers are leaking.

It's hard to measure the battery because of the BMS system. This system discharges and charges the battery based on a software model. Probably the best indicator is what the voltage is after the car has sat all night. You need 12.6 VDC or more. I added a cigarette lighter plug in voltmeter with a USB port in the console. So now I can see what the voltage is at anytime. It was only about $10-$15.
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So I picked up some O rings and fixed that booster leak for now, what a PIA to get to that little screw. Took me abour 1.5hrs to build some tools and figure out how to get it out as alternator pulley was in the way, hindsight should've done it when I'm doing alternator... 2.5hr job in total but fixed and no oil leak there anymore.

These are some of the redneck tools I had to fabricate 🙄




This morning car had 12.7V on my fully charged new pickup truck battery) after sitting all night, as I swapped as a test last night once I fully charged it 12.9V. Which is this battery...



This is the battery the car came with and the previous owner said is 6months old


once I know I need a new battery I will get a 49S (no worries) just doing some testing currently and pickup truck battery is plenty capable and new.

So after fixing oil leak from booster with car running while down there i checked voltage with volt meter straight from positive alternator post to ground... was getting 12.1V, nothing was put out.

Turned car off and checked voltage again at battery, 12.4V so it dropped... probably car running off battery and alternator not kicking in. Checked grounds and positive leads again and nothing suspicious.

Back to the timing cover, yes looks like it's weeping/leaking there down into the alternator.

what probably fries it guaranteed...

Was thinking do engine upgrades maybe next year or whenever needed (sc coupler, service sc, snout, all metal cooling pipes & timing chains/guides all in one swoop). No symptoms of any of that needed yet so be a shame do rip that much apart right now... especially since I just got the car I'd like to enjoy it first before just it becoming an endless project and money pit right off the bat.


Back to Redneck options... was thinking if replacing the alternator i might just build a diy alternator oil protector cover for now to get me through until I have to rip the engine apart or get it fixed at a mechanic that will work on the Jag (3.5hrs away). i might get some backlash for this, but the main leak was the booster o ring, the little weeping from the top is just enough to keep cooking alternators is my guess, so if I can guard it, until engine needs all the major work, i might have to try that for now.
I'm ok with putting $ and time into it down the road, but not another 5-10k right now for all the major work & minor timing leak, as I just bought it a week ago.

 

Hate to see you had to weld on your wrench but yes I do that too. The tools are a bit sacrificial compared to getting the repair done for me!

I would spend some time cleaning the oil off the engine first. Remember that vacuum pump was leaking oil and that oil will be smeared all over. Now that the leak is stopped you "may" not have an additional leak? Just a thought before you start tearing into a big repair.

One note on alternators is we have found (again!) that rebuilding the OEM unit usually causes the least amount of problems. For some reason many have had continuing problems when replacing the alternator instead of rebuilding the original.
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Much appreciate your replies!

Yes sucks to sacrifice tools but still cheaper & quicker going to a mechanic... most mechanics in my town want nothing to do with a Jag unfortunately, next Jag mechanic is 3.5hrs away when things get serious, so I'll try to do what I can! A 1/4 wrench will cost me like 5 bucks and a torx bit 😉

Definitely will clean it up with some degreaser/ water once I got the alternator out & can get in there better. It definitely appears tho that there is some oil sitting on timing cover, possibly the stuff that got into the alternator, but that's not what has been leaking severely, I think alot of it came from that stem leaking and then splash back while driving/fan kicking on is my guess...

Not sure yet if that is the factory alternator, previous owner mentioned he had alternator refurbished 6 months ago... so who knows 🤷‍♂️

All i know is that I put a fully charged battery in yesterday evening 12.8V (so i can unlock trunk etc. Still) and today when tested without any starts just sitting for 24hrs, the battery was down to 10.1V. Clearly a heavy drain.
No red triangle (battery drain) light on dash, doors double locked, so suspecting the diodes of the alternator putting a drain on the battery at this point.

When I tested battery couple days ago it was 12.4v without car running straight off the battery & when car started and checked off of the alternator it was 12.1V.

Which tells me slight voltage drop because of car running, but alternator not kicking in to charge battery & at the same time voltage wasn't abnormally low on alternator hence why I don't suspect a corroded connection inbetween. It basically gave me a pretty accurate battery reading, but off of the alternator. Is this right?

Alternator is on the way, will be here Thursday, also got a set of ratchet wrenches coming so should be fairly trouble free to get it out... might remove tire & wheel well too, will see!
got a 'cheapy' for now I'm gonna experiment with, might wrap top side with aluminum sticky foil to keep oil off but still keep it ventilated enough from front/rear/bottom.
really don't want to spoil a 1000$ alternator before upper oil leak is fixed (maybe next year if i come up with funds for all repairs) will find out!
if it fries in 2 months, I can always get an ACDelco for around $500 CAD locally & at that point I can see if an oil cover is even necessary, or if it possibly be cheap alternators burning up...
few things to test & keep in mind, but really want that beast up and running for now again since I've barely had any time to enjoy it yet! Been wrenching around more hours than driving it since I got it 9 days ago. 🤣

 

If you have some current drains maybe this will help?
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I tried a different 'older' battery overnight this time, only fully charged to 11.9V as it's kinda old but checking it now after 20 hours it's only down to 11.8V, so doesn't seem like a major drain afterall. Battery that came with car definitely seems done tho i suspect now. Maybe overloaded the alternator trying to keep it charged to the point it overheated with slight oil on it?

Either way, new alternator should be here soon & probably in for a new battery too! will keep updated

 

Took the alternator out today, about 1.5hr job to remove, not too bad.
Can't tell if it's oem tho as I don't see any tags or anything at all even describing it.

Might buy a used oem one from Ebay as backup, to keep rebuilding if I ever have to. But currently waiting for my new cheapy temporary test alternator that is suppose to arrive anytime today, hopefully car will be up and running fine again after, might still go purchase a new 49 Battery... Acid lead fine or go with a AGM?
i thinkian acid lead battery came out of car. But appears like its not holding charge well... i think it toasted and alternator over compensated and fried itself.

Not too much crazy amount of oil coming from above... hard to tell if valve cover gasket or upper timing gasket, I'll keep an eye on it and possibly do that job next year.

 

Kinda odd that the alternator has no ID tags of any kind?
I use AGM batteries.
Your in Canada but I like the H8 (Also called a type 49 in the old nomenclature) battery from Walmart as it has a 4 year warranty and Walmart is everywhere so warranty is no problem.
H8 AGM Battery
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My XF is still running on a 2017 Jaguar factory battery which is supported by a C-Tec when in the garage. I used a Walmart H8 on my 2004 4.2l S-type and found it very satisfactory.

 

Thanks guys!

Alternator arrived this morning, took me about 30 minutes to put it back in and lower car & hook my fully charged pickup truck 'test battery' up that was brand new 2 months ago back up.

This car is making me anxious 🤣 Moment of truth...

Started up and battery light instantly came on. figured what the heck lets take her for a test run 30minutes to town and grab a new 49/H8 battery. Since new battery is fully charged & I just put a brand new alternator in, so it might stabilize itself.


Obd2 reader hooked up to keep an eye on voltage, this is what it looked when I left my house.

Town I arrived, got some fuel and stopped to grab a new battery & some groceries... I didn't change to new 49 battery yet as I need to fully charge it first. Everytime starting the car battery light came back on and obd2 reader kept reading less & less. This wasn't looking good... no alternator kicking on just essentially driving on my battery.



Crossing my fingers another 30minutes home back from town hopefully I can make it. Leaving, looking at obd2 reader like this, anxiousness kicking in. Worst case i could switch to my new half a** charged new battery i just picked up to atleast limp it home i figured.

15 minutes into the drive home I was getting voltages below 11V even with everything turned off- fans, no stereo.

driving... Slow guy ahead of me figured I have no time, peddle down to about 3500-4000rpm and went for a quick pass. Before I was just putting 1.5-2000rpm all the way.

All of a sudden voltage on obd2 SPIKED as I'm passing as if something activated after this whole time for the first time.


Good morning Alternator!

Kept cruising normal after and it stayed around that voltage whole time, like wth is going on? Do these jags have to be gunned at times for alternator to do its job?
Not gonna lie, I've been babying it pretty good since I got it so maybe that was my whole issue with alternator never charging right?

Just weird even after when I was cruising home normal it stayed charging (battery needed it), did alternator need an awakening or is something in alternator faulty already?

Love the car but definitely a nerv wracker 🤣

 

Started the car to wash it at home and battery light still on. Haven't charged that battery yet but it's back to 12.2V so it definitely got some juice in the last 15mins of driving.
figured i might aswell scan the codes and see if I find somethings suspicious since battery light is on and batt. Light turned on right on first start after alternator change with freshly charged full battery.

This is what it gave me-



Literally this was the message I had seconds after I started car 1st time after alt swap. Hasn't left until now that I scanned it & removed DTC.

Fired car up again and checked if it came back right away, nothing yet on startup like 1st time. Will have to test more as soon brand new battery I picked up today is fully charged & installed.
probably will reset BCM aswell just to give it it's best chance!

Feel like I'm chasing my own tail lol.

 

My 2012 XF has a Battery Control Module attached to the -ve terminal. Normally when the car is running, I see 14.5-13.8v but when the BCM does its routine I see less until the routine is completed. I would assume that your 2011 has the same system but I do not know for sure. When I put the battery in the car I did not reset the BCM and eventually it reset itself.

 

Yes it appears to be the same system, a fuse link from positive terminal to - post bcm. I'm getting above 12V on that plug for the bcm so i suspect it is working.

I took the car out for another drive with brand new battery, was charged 14.1V when installed and before i left my driveway it said 11.8V and battery light came back on. P0a1a code.
same thing again, this time i punched it to 3000rpm right away and alternator has seemed to kick in. Ranging from 13.3-13.5V all the way to town again (30min drive), picked up a couple things and everytime I shut car off and restarted battery light came on and showed 11.8V until I once again increased rpm quick, then alternator brought volts up again to 13.4-13.5V.

Once at home I checked brand new battery Voltage and it is reading 12.8V.

Not sure what is going on at this point... maybe because of aftermarket alternator? Might have to get myself a 'used' OEM and see if that fixes it.

Connections were clean when I reinstalled the new alt.

 

Yes this has happened before. That's why I recommend to keep the OEM one and try to get it rebuilt.
We had an old time member Bigg Will and he had his rebuilt and upgraded to a 250A version. Just depends on how good of a re-builder you are using.

Hope this will heal itself but I like your backup plan. A used OEM one should be OK to just bolt it on too.

The tag is not very durable so maybe I was wrong about yours? It might be so faint by now.
Here is what you looking for.




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