Big John

Hi Graham Are we talking about an external leak which is dripping on the floor or coolant level dropping with no obvious source? If advised at MOT I assume it is an external leak. If that is the case it is hard to imagine what would make it irrepairable. The system is a reservoir, hoses / expansion tank, radiator, pump etc. Only thing that would make me consider scrapping an otherwise good car (particulalry if it is only an MOT advisory) would be heater matrix which can be expensive in labour to replace due to its access problems. Have you tried some radweld or other sealant? John

My favourite approach is to get tooth floss between the badge and bodywork (best on hot day or after hair dryer treatment to soften glue) and gently slice through the glue, Give yourself plenty of floss on both sides to get hold of. Had a bad experience once with prying off which can take the paint with it 😞 John

Hi John Don't think it is installed on all models. On mine that button rejects or ends phone calls. Still love the car though 🙂 Regards John

Hi If the Stop/Start is working the Battery is probably fine as the computers only engage the system when they are 100% certain there is enough energy to restart. Only other suggestion would be a poor connection on the battery or earth which has caused a momentary drop in voltage to upset the software. Other than that it could be a real fault in one of the modules. My next port of call would be a Jag dealer or Indie specialist for a diagnostic. Good luck John

Hi KP and welcome. You certainly seem to have covered the usual cause of such problems with a CTek. However if the car is still on its first, or even its second battery it could be the battery is the source of the problem if it is starting to fade. If voltage drops then the various computers can have their software corrupted and the central locking / alarm seems especially sensitive to this. If this is the case you will probably need either a Jag Dealer / Specialist or a Garage with the AutoLogic system (and the knowledge of how to use it) to correct the issue . Have you checked the actual voltage at rest and during start up? Does the Stop/Start work? How old is the Battery? It is an AGM? Regards John

Hi Brian Welcome to the club. First port of call with warning lights in the XF is the battery. These cars (as with all modern luxury cars) are a couple of dozen computers all chatting over several networks with a wheel at each corner. If the battery gets even slightly low it can trigger all sorts of random errors. Given we are still in a pandemic I imagine your driving has been limited to a fewer long runs so it could well be that the battery is a bit tired. It is also quite possible your car is still on its original battery and in need or replacement. If you don't have a voltmeter a little cigarette lighter LED voltmeter is around £10 from eBay and a good place to start. If you can either charge the battery using a good maintainer (Don't just take the battery out to charge it can cause all sorts of issues) or take it for a long run with minimal use of accessories. Hopefully this will sort it but even if it does you may need to clear the fault codes. If not you will need to get the fault codes from either a Jag dealer or a Jag specialist to look for any "real" fault. Not long after I got mine 2 years ago I got a faulty air suspension warning after I had been sat waiting at a railway car park playing with the toys. After a run problem cleared. Fingers crossed John

Hi Peter That is fine because there was an event that made you stop and check, then proceed at slow speed to get home. The problem when used without TPMS is where it is a slow puncture and you come to need high speed braking and/or steering response only to find the tyre is actually deflated! In that scenario I am pretty sure the insurance would be an issue as you had modified the car from standard.... If RFT are not specified in your handbook as a fitment my advice would be do not fit them. Kind regards John

Hi. My understanding is that you should NOT use RFT unless you have a car with Tyre Pressure Monitoring (and the correct rims) as it is not obvious when you have a puncture and can therefore be dangerous if you continue to drive at speed with no tyre pressure. Regards John

Hi Darrell No need for a code. Mine is 2013 and checked direct with Jaguar when I got it. Kind regards John

Hi You should always replace an AGM with an AGM. They are a very different design to the standard (including Calcium) wet cell. The main difference is their ability to recover from deep discharge which is what you get with stop/start use. In addition the cars charging system is designed for the difference so if you use the wrong sort you may well get a premature failure of the new battery if it is not an AGM. https://batteryuniversity.com/learn/article/absorbent_glass_mat_agm John

Hi Basically white smoke is normally steam, so first look at cylinder head gasket or cracked block. Any sign of oil in the coolant or coolant in the oil (looks milky)? John

Hi James Only useful thing I can add is here: http://www.jagrepair.com/images/Electrical/XFWorkshopManual/2010XFRWorkshop.pdf which is a really big file to dowload. Other possible sources that may help are here http://www.jagrepair.com/JaguarXFElectricalOBDIICodes.htm and here: http://www.jagrepair.com/images/Electrical/XFWorkshopManual/Battery and Charging System.pdf When you've looked at some of these manuals you will see just how many sources of the problem there could be. I would certainly need a garage to sort it 😞 Really hope you get it sorted. John

Hi James. I am assuming that the problem now is the warning message. Have you watched the voltage with the engine running? A real problem with charging should flatten the battery pretty quickly. My gut feeling is that you have a software issue and basically it needs a Ctrl+Alt+Delete to clear the error message. To do this you either need the proper Jaguar computer or a garage with the Autologic system (and the know-how to use it properly). If it was me I would bite the bullet and get a diagnostic from a Jag dealer. I had an issue with my parking sensors / camera and have a really good warranty from the non-jag vendor. They could not sort it (replaced the sensor their computer said, and it still didn't work). So I took it to Inchcape Jaguar in Preston after agreeing a diagnostic at a cost of £100 +Vat. which I felt was no where near as scarry as I expected. They diagnosed front bumper wiring loom and replaced it (not covered by warranty) for less than £300 inc VAT. The genuine loom was £48 inc VAT when used ones are on eBay for £100 so maybe worth biting the bullet. If it is just software issue it might get sorted within the hour they charge for a diagnostic assessment. Good Luck John

Hi James Just a thought but is the new battery an AGM? If previous one was a wet-cell that would explain its premature failure. John

Hi James When you say you have put a meter on the terminals are you just measuring voltage at the terminals of the secondary and main batteries with the engine running? Secondary battery is normally not connected to the charging circuit except when charging so you are probably just measuring the secondary battery resting voltage. If the main battery voltage shows as 12.2v when engine running but then slowly rises after you turn off and lock the car the computer is almost certainly running down the battery doing a self calibration. When it gets to 75% of capacity it will then fully recharge the battery. This behaviour caused me a few days of panic before I found the info on the web. My hope would be that is where you are but you probably need to pull the fault codes to be sure. The computers hate low voltage so hopefully the codes need clearing and possible some modules just need a reset. Fingers crossed John

Hi David This is the best resource I have found: http://www.jagrepair.com/JaguarXFElectricalOBDIICodes.htm John

Also....Don't forget that both batteries need to be OK as the little one is there to ensure the voltage to the computers does not get problematically low during the stop or on restart and the computers are very hungry on power. 🙂

Hi Depends what you are asking 🙂 If you are looking at buying this and it is advertised as an S then I don't think they all had a front badge but it should be described as an S on the V5. I think there is some confusion over the S and Sport designations, I know I am confused. Mine is a 2.2 200 Sport Sportbrake which means it is NOT an S but has the sport bodykit (as does the one in your photo - Main difference is more aggressive looking nose). I think the S refers to the high output version of the V6. It is a matter of personal taste but I prefer without the badges. If you do like them I would suggest looking on ebay for the self-adhesive ones unless you are happy to take the front bumper off (not as big a job as it sounds) to fit it. John

Hi Look into the fuel filler. You should see the "after" view below. If you see a yellow flap as in the "before" picture the mis-fuelling protection has been triggered. There should be a yellow plastic tool stored on top of the battery to sort it. It simply fits into the filler to flip the flap back up. It is also fitted to Land Rovers. Instructions here: https://www.rrevoque.org/diesel_misfuelling_protection_device-2963.html I think many car dealers use the same size fuelling nozzles for petrol and diesel so inadvertently trip the device which is designed to prevent you putting petrol in by mistake as a "petrol station", "petrol" size nozzle triggers the flap and blocks the flow to a trickle. Regards John

Hi My understanding is that the supply from the negative side of the charger should NOT be connected directly to the battery terminal. On the XF the Battery Monitoring System Module is integrated into the earth lead at the terminal. If you connect the charger directly to the negative battery terminal there is no "flow" through the BMS when charging from the ctek so the car does not "know" the correct state of charge. The CT5 (S/S) instructions say to connect the negative to chassis (which is what you would do if jump starting. https://www.ctek.com/storage/BB1B5B957F380A58AA7DC41C3D76EDDAE9ABFB3DBBF332368F7ED9E677205D60/7ee76813a1594b14ab69bb0d34ebdb8c/pdf/media/d32b8d87593840368e1c79dac6384cab/CT5_START_STOP-productsheet-low-UK-EN.pdf I have mine hooked up through the "comfort panel" with the positive connected to the battery terminal via a fused connection and the negative to earth through the chassis. I then have the cable run through the gap at the side of the spare wheel cover so the connector "panel" just sits at the side of the boot peeking out from the OEM Jag rubber boot liner 🙂 There are several alternatives available, but I like the Ctek CT5 Stop/Start because of its simplicity and the fact it is designed for AGM batteries. If considering an alternative the key things to look for are that it is not just a charger but a "maintainer" and can be left attached without risk of over-charging, and it is capable of working with AGM batteries. This requirement usually means a separate "mode". If you have other vehicles with normal wet cell batteries you should consider something like this: https://www.amazon.co.uk/CTEK-MXS-5-0-Reconditions-Motorcycle/dp/B00FC42HAA/ref=sr_1_5?ascsubtag=1ba00-01000-org00-win10-dsk00-nomod-uk000-gatwy-feature-SEARC&dchild=1&keywords=ctek+battery+charger&qid=1615294510&quartzVehicle=29-10519&replacementKeywords=ctek+battery&sr=8-5 which is also very good. Being a gadget freak I have both 🙂 Regards John

Hi Philip I use this one: https://www.amazon.co.uk/CTEK-Start-40-106-Battery-Charger/dp/B00YBR8PFK/ref=sr_1_1?crid=1P2BOBHUTT6JG&dchild=1&keywords=ctek+stop+start+battery+charger&qid=1615229884&quartzVehicle=29-10519&replacementKeywords=ctek+stop+start+battery&sprefix=ctek+stop%2Caps%2C162&sr=8-1 along with a Ctek panel which has an LED indication of battery state which is permenantly wired in the boot. Jaguar do actually do a Jag branded version of the Ctek. I keep my charger in the boot, connect it to the panel when I want to charge and just close the boot (Sportbrake) on the mains cable which then goes to a waterproof plug. I would strongly recommend the use of a Ctek especially if you are not doing regular long journeys. Hope that helps John

Hi Frank and welcome. The stop/start system will only stop the engine when the car is sure that there will be enough "left" in the battery to restart it. So it will not stop if you have the Air-con on full blast for example, or if battery is voltage is low or the engine is cold etc. Usual cause of s/s not working is low battery level. It is very common at the moment with the lockdowns we are all enduring. If it has been sat and just done short trips to the shops it could just need a good run. Personally I am a big fan of the Ctek trickle chargers to keep the battery topped off. It is also worth getting a simple cigarette lighter socket voltmeter to keep an eye on the voltage. Certainly in the x250s the battery is an AGM which has a different voltage profile to an ordinary wet cell but is capable of withstanding deep discharges. 12.8v at rest is pretty full 12.2v at rest is pretty low. It is worth noting that battery voltage may well show below 12v when starting but that is with all of the computers running rather than at rest. A quirk of these cars is the battery management is a bit too clever for its own good (IMHO). every six months it will actively discharge the battery to 75% and the voltage when running will be held around 12.2v. It does this so that it can work out how able it will be to restart the car. In my opinion that is fine unless..... it gets to 75% just before you park up in a pandemic and doesn't get a chance to recharge. Hence my advocacy of the Ctek chargers 🙂 Of course at 5 years old you may be due a new battery anyway 🙂 Kind regards John

Battery connections all tight?

Hi Craig If you were having gremlons it is almost certainly a low battery. This is proving a common complaint in lockdown with us all using our Big Cats far less. I am a big fan of the Ctek maintainers for keeping the battery topped up. How old is the battery? If you have Stop/Start is the main battery an AGM? Regards. John

....Forgot to say this is due to faulty Crank Position Sensor.