My 2017 3.0L s/c engine is one of the finest I've encountered.
But after 7 years of development since its inception,
Jaguar engineers continue to struggle with cooling this dragon; imho.

Given that life itself is full of compromises, I took the plunge on a CPO XF.
Beat out 540i, A7, E400.

After asking 8 different Jag dealers the maximum safe coolant operating temp,
only 1 (Cincinatti Blue Ash) came back with specifics.
The most egregious answers ranged from "that's what the coolant gauge is for" to "just bring it in if it overheats".
SMH..
I've often wondered if Brit Techs are as obtuse as most American ones?


The Blue Ash Tech said "thermostat opens fully at 205F.. if temps creep to 230F then we need to determine the cause. At 15psi, a 50/50 coolant mix boils at 260F so you'll have a little headroom if a problem crops up. But the modern Jaguar temp guages are really only "pull over now meters".
Ok.. that's more like it.

Knowing the TSB histories on the AJ126 engine, I purchased the Torque Pro Android App and mounted my old smartphone up on the dash. (See pic)
Real-time measurements seem not to be what Jag engineers want you to know as these data points were readily available in my 2015 Mustang.

Further, my coolant tank was at the Min mark upon purchase and it's a CPO still under JaguarElite Maintenance. This has many possible causes such as the out-of-round tank filler neck or the weeping water pump revision #6, or the thermostat housing seal issue, or the cross-over/y-pipe issue, or etc.. LOL!

I do have the original Sept 2017 water pump as my DDW history shows no replacement.

1. Still can't tell when AJ813909 became available?
Anyone... Bueller?

2. My attached pics do show dried coolant residue on my engine front, agreed?

Watch this thread as I update my findings... from any coolant loss to my temperature findings.

Thanks for any insights!
-VirginiaF1

Graphs are left & right cat temps..

Cold mark..

Which part#?

Dried Coolant Residue?

 

Yeah that absolutely looks like coolant residue on the front of your engine. It sounds like you are taking every precaution but definitely keep an eye on that situation and your coolant level.

 

DTC: P0496 surfaced today after 400 miles of my ownership. (@35k now)

Purge Control Vent Error related to the fuel vapor charcoal canister.. full after just 3 years already?
I see a TSB on this code leading to a software update or ecu replacement. We'll see..

Coolant has ranged from 195F to 223F in operating conditions during 96F ambient this week.
All with absolutely ZERO movement of the Jaguar Temp Needle. LOL!
I realize its prolly best for non-techie Jag owners but just glad I have Torque Pro Real-Time.

No performance issues but dropping off Monday; will update thread once disposition known.

Really impressed with my '17 XF despite the error code.
36mpg highway in ECO.
0-60 in 5.3 in Sport.
Fast, quiet, comfortable and looks great.

 

I read on another forum that the temp needle moves in increments, not linearly. That could explain why it staid at 9:00 over a 28 degree range. Maybe that's within 'normal' operating range once the motor comes to temperature. Personally I prefer linear readout in F or C with the normal range noted but that's rare on new cars these days.

 

Yep..
I do recall the "5 minute average" depiction..
Guaranteed cash for main agent Jaguar technicians once the lump boils over.

Torque Android App is my favorite $5.00 I've spent this year!

 

" Ernest Howard , 5/3/2021 02:25 AM
Junior Member
Hello F1 Virginia, I'm new to the forum so please excuse my lack of decorum, I just read your post on the loss of coolant or in my case coolant loss without a trace, although I suspect that the shroud that encompasses the underside of the vehicle has done an excellent job of keeping the coolant from leaking onto the ground (too bad they cant figure out how to keep it in the overflow bottle. What I would like to know is? What was the culprit? I am Heartbroken in the 2 years I've owned mine, I've never had any issues and now this, To make matters worse I live in the California desert, so a lack of coolant is a possible death sentence, and so I've been driving in eco mode and not exceeding 70 mph with a backup container of coolant, The coolant seems to diminish quicker under high load not to mention the dreaded RED Low Coolant Warning. at $21.00 a pop for coolant, it's more expensive than fuel.
I'm curious to know what was the outcome since my situation sounds very similar to your experience."

My coolant loss continues albeit at a far slighter volume.

I examine my oil level (electronucally) and my coolant (visually) every 5 days. Too many threads of doom here preventable by weekly review, IMHO.

My coolant loss now goes from MAX to just under MIN (warm engine) within 1,000 miles vs just 300 miles before the Reservoir Bypass Tubing was replaced 6 months ago.

Aero Under Tray prevents drips but likely culprits are Water Pump itself, Rear of Engine Tube, or the notorious Y Tube seams.

Fwiw, drove an '18 G80 as a Loaner and absolutely loved it.
Ima create a thread soon on X260 rivals..

Let us know your coolant loss findings Ernest..
Cheers!

 

Thank you for your prompt response, I'll be taking the vehicle in today to see what they find. fingers crossed!

 

The thermostat begins to open (with ambient temperatures of 15-35°C (59-95 °F)) at 98-102 °C (208-215 °F) and is fully open at 108 °C (226 °F).

 

My next step will be a replacement of my original (2017) water pump to the latest revision: AJ813909.

https://parts.jaguarvirginiabeach.co...embly-aj813909

This is Jaguar's 9th water pump revision since 2010.

I don't know if I should be impressed or scared off..LOL.

As I have 100k CPO Warranty, I've been advised that replacing it is covered if catastrophic failure occurs..
So comforting.

 

Check how many pins has the sensor. If more than two, it has more than one circuit.

 

Hi Zax,
The Coolant sensor?
And what is the diagnostic relevance of single vs dual circuitry?
Thanks!

Ernest, it's been 6 weeks with your fingers crossed.
What was determined?
Please don't be another "1 & Done Poster.."

 

if you have two circuits, there is a separate indicator on the computer.

 

Hello F1Virginia, thanks for this post. Did you end up getting your water pump replaced? I bought a 2016 X260 3 weeks ago and am having coolant issues also. It has 60K miles and as far as I know the pump has never been replaced. I can see orange residue all over the front of the motor, not sure where its coming from, but I am assuming it s the pump and will need to be replaced. Any advice on what to look for when trying to find the cause of the loss of coolant? It will go from Max to below Min in just a couple hundred miles. Once again, thanks for the info here!

 

Hi Chadly, sorry for your issues but Congrats on a great car!

Any Jaguar Dealer Service Dept can run your vin# and detail the parts that have been replaced. They'll also tell if your XF is still under any 100k CPO Extended Warranty.

Alternatively, you may also call 1-800-4-Jaguar.
(Or pay CARFAX for a report; I keep an annual subscription with them for $99/year to review any cars my family & friends are considering.)


Knock wood, my '17 CPO with 45k has stopped losing coolant as of this year!

Every morning before my commute and once I return home, I check the reservoir and go from just above MIN to just at MAX. (Cold vs Hot Coolant)

Although my non-leaking pump is original, it's not the latest revision so I do not trust it; thus the twice daily check.

I also do a cold & hot oil test daily. No loss..

My aforementioned reservoir tube was the leaky culprit.
My Y-Tube was factory revised before production.
Iirc, 2017 MY was the first with the better Y-Tube design.

Let us know your findings...
You may need to call a few different Jag dealers to find someone pleasant & helpful..
Sad but Alas..

Hot Level..

 

Thanks for the info brother. Been super busy, but had some time to do some looking today, it appears the wettest part is just under the water pump. I'll take stuff apart this weekend to get a better look.

 

Hi Marine,
Did you ever get to the water pump leak cause?

 

How much in estimated volume would you say you are adding to go from min to max, and this is daily? how long is your average commute/drive time?

Secondly - I am still learning the best time to check the oil in both my x260 and my x250. I can only seem to get a reading after its been driven and sat. What is the difference between cold and hot test?

 

I add neither coolant nor oil daily..
The coolant Min to Max change is due to thermal expansion of the hot vs cold coolant.

My coolant loss is 1 inch of reservoir over about 3 months.
I drive 1,000 miles monthly.
No coolant smell or sight so it's a subtle weeping from the 4 main suspected parts: y-tube, thermostat housing, water pump, tubing/connectors.

Should get my Blackstone 15k mile analysis tmw and will post here..

No oil loss over 15k miles and Cold vs Hot oil check shows 1 inch of change on my electronic Guage.
(mid-to just under max)

 

I just finished replacing the water pump and seals, oil cooler and seal, ypipe, crossover pipe and some nasty hoses, coolant isn't leaking (from what I can tell looking at the reservoir)...but, my heat is blowing ice cold and I can smell coolant still...bad heater core??

 

Had a similar issue with coolant loss and residue in that area... got progressively worse and ended up being the water pump. 🤑.