Hey Guys! I'm new to the Jag forum as I've just purchased my very first Jag: a 2017 XF 20d. It will be my daily car (replacing my older BMW F10 520d). Today I had the pleasure of doing the first 400km in it and I absolutely love it. It's something very different to my BM and the feeling it gives you is unique.

Appart from the fact that it drives as expected I noticed a small issue. While driving around town and at high speed on the speedway (120-130 km/h) the cooloant temperature indicator sits right in the middle, as it does in all vechicles. But as soon as I slow down to around 60-70 km/h and cruise at constant low speed outside of town, the arrow drops to the middle point between where it should be and cold. Now, I've had this problem in my BM also and it was the EGR thermostat (the BM has 2 cooloant thermostats). It did not close fully anymore.

Is it possible that I might be dealing with a deffective coolant thermostat in my XF also? Should I be looking for other causes also? Where is the thermostat in the XF 20d located? Many thanks!

 

Welcome!
Sorry it's been 24 hours and no one else has chimed in yet..
October is busy season for many of us.

Your suspicion seems well-founded given your similar Bimmer issue..

Did you use the Forum Search feature here yet to peruse causes?

Also, in a nutshell how did the heavier BMW differ in terms of driving dynamics and NVH?

 

I've scheduled on Friday a visit to JLR, since I'm due for an inspection anyway, and will be diagnosting the problem with them. But I can almost guarantee that the thermostat will need to be changed.

I tried using the search feature and managed to find some issues with the thermostat but blocked on closed, which would cause overheating. Mine, I suspect, is the other way around, as my engine is not getting up to temperature properly.

The XF 20d has a very similar driving experience to my F10 520d. The gearbox is the same (ZF 8HP) and the engine is pretty similar to the N47 (184 HP) on the BM. The XF is a bit more stable on the road, but it might come from the fact the my tires are wider versus what I had on the F10 (245 vs 215). Coming from the F10 I have absolutely nothing to complain about the Jag. I actually love the change after a long line of BMs (1 E39, 2 E46, 2 F10). The Jag feels more special and it gives off a diferent and refreshing vibe.

 

Did you get any solutions on this coolant temp variation?

I live in Finland and have XF with the same engine and the same problem. At first car stopped almost completely warming up the motor and cabin. The service replaced thermostat and cabin gets warmed up pretty normally, but in my opinion the coolant temp started to variate, car having problems to reach normal temperate. It gets to 1/4 of cauge in 4 miles in Finland cold weather, but it seems like you have to drive 20 miles in city to get to the normal temp. However, driving motorway it warms normally. No error codes. The service is saying hey it's a diesel that's normal, but I find it hard to believe.