When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have had my XKR for about 4 months. 2014 XKR Dynamic, 85K miles, I have been in contact with the former owner and the shop where he had service done. It was well maintained and all coolant hoses have been replaced, I have been able to verify they all appear to be young compared to the car. Since I have owned it there has been a faint smell of coolant after short runs, could not find the leak until recently. The Thermostat Housing was leaking where it bolts together. I attempted to tighten the bolts and this only changed the leak. The part is not very expensive at approx $40 US. I am choosing to change it but am running into a snag.
In the 2 sq in space you have to work there are 4 hoses that enter the housing, the 3 with clamps were a pain but I managed to remove them. The one with the clip at the bottom will not unseat, I have completely removed the spring clip and still cannot get it to separate from the thermostat housing. For those of you familiar I am speaking of the housing for the Engine Coolant Temperature Sensor that is on the bottom of the Thermostat Housing. How do I separate this thing?
Hi! When removing the sensor, leave the coolant sensor connector on the sensor before trying to disconnect the sensor. You should be able to lift the small plastic piece coming off the side of the connector up and turn it counter clockwise to disconnect it. When you turn it, will it not turn or is it just difficult getting a grip on it?
Last edited by Sabrinaservicewriter; 02-23-2022 at 12:59 PM.
Reason: Additional notes
Thanks for the reply Sabrinaservicewriter. I simply unplugged the sensor, that isnt an issue. I am hoping to remove the adapter that the coolant sensor is in from the thermostat housing. Those 2 hoses on the bottom of the adapter are difficult to disconnect from above. I did purchase some long handled pliers that should assist when I attempt this again. But the issue will still remain that the adapter will need to be removed from the thermostat housing and I have not been successful with the components still attached to the vehicle.
Hey SupJager,
I showed this question to one of my techs to see if they could share some knowledge and help you with this. I really wish we had your model car here so we could see exactly what's happening. You have to wonder, what were the engineers thinking when they designed these engines for mechanics with child sized hands to work on. I was hoping I could be more help! I'll take a look at some of our resources we use to see if I can find some more helpful information about this.
That guy hasn't been on in over two years. Four total posts. Guess he lost interest long ago.
Don't assume! Still very much here, spending more time at the track than behind the keyboard. Interest has not been lost, just enjoying the car being problem free!
I know it's a two year old thread. I'm having difficulty finding an answer.
@SupJager What was the final solution to your problem with getting the thermostat housing uncoupled from the adapter. I'm having the same problem.
Thanks.
Scott
I've done this several times, with age, the two pieces become fused together. I used a slotted screwdriver and multiple taps all around to eventually separate them. I used a bit of silicone grease on the new parts and subsequent services to these parts was much easier.
I cannot remember for certain but I do believe I sacrificed the skin on my arms to get a good grip on that to twist and pull it apart.
Hi SupJaguar, Now we have your attention.
What was the cause of your Leakage/Issue on Thermostat housing?
Mine on the XF 3.0sc has a (very difficult to find ) leak/weep from one of 3 screw holes on the Thermostat cover. Only really evident when hot and engine under load on a long runs.
Since it is a Plastic housing, non sensor type, I am looking at going for the alloy body type. I feel the silicon sealing ring is unlikely to fail, but the top cover 3 screw plate has distorted somewhat.
and something else to add to the XKDR replacement parts list.
Is there an o ring or something in the connection between the thermostat housing and the plastic coupler. I have only been able to move the housing about a millimeter so far. I have pulled up hard on it. I have also used a tool used to pry rubber hoses off to try and press the parts part. It almost feels like there is something holding it in place. And yes the clip has been pulled out.
What was the cause of your Leakage/Issue on Thermostat housing?
Mine on the XF 3.0sc has a (very difficult to find ) leak/weep from one of 3 screw holes on the Thermostat cover. Only really evident when hot and engine under load on a long runs.
Since it is a Plastic housing, non sensor type, I am looking at going for the alloy body type. I feel the silicon sealing ring is unlikely to fail, but the top cover 3 screw plate has distorted somewhat.
and something else to add to the XKDR replacement parts list.
Thanks,
Now that I am getting so many questions about this I wish I had taken notes. Sadly, the brain cell that would have permanently saved the information about this has perished! I suppose next service of any sort I do I will take plenty of pictures and notes so I can post a how-to on here. No sarcasm, I wish many of those exist that do not.
Is there an o ring or something in the connection between the thermostat housing and the plastic coupler.
So to answer my own question, YES, there is and o ring between the thermostat housing and the plastic coupler. It was very difficult to get the housing to move more than a millimeter with it in the car connected to the coupler. I ended up removing both pieces and they pulled apart fairly easy. I highly recommend removing both pieces at the same time if they can't be easily separated in the car.
Bydand, there is a rubber O ring between the top of the thermostat and the body. The 3 screws also have a very coarse thread like a woodscrew. When I removed mine from a 68K mile 2010 XKR, I noticed that the top had bowed even though it wasn't leaking. I went your route and purchased an aluminium C2Z19929 thermostat from a seller on AliExpress for about $38 delivered to the US (So Cal). The seller ID on AliExpress is 1102728505. It is part of a cooling system upgrade I'm making to my 2010 XKR 5.0 which includes a new water pump, rear crossover tube upgrade to alloy from plastic, water pump to oil cooler connector in alloy and a Bosch 0392022010 supercharger cooling pump in place of the OE Jaguar version. I also replaced the coupler on the supercharger and changed the supercharger oil.
Bydand, there is a rubber O ring between the top of the thermostat and the body.
The 3 screws also have a very coarse thread like a woodscrew.
When I removed mine from a 68K mile 2010 XKR, I noticed that the top had bowed even though it wasn't leaking. I went your route and purchased an aluminium C2Z19929 thermostat from a seller on AliExpress for about $38 delivered to the US (So Cal).
The seller ID on AliExpress is 1102728505. It is part of a cooling system upgrade I'm making to my 2010 XKR 5.0 which includes a new water pump, rear crossover tube upgrade to alloy from plastic, water pump to oil cooler connector in alloy and a Bosch 0392022010 supercharger cooling pump in place of the OE Jaguar version.
I also replaced the coupler on the supercharger and changed the supercharger oil.
Hi LosRubios,
Its not an O ring per ser, more a seal ring, U shaped with a flat face, and an oval face. and basically too short. see the long story below of findings of the plastic, and Al housings.
The plastic housings have the coarse screw fittings, which screw directly into the plastic body, and the Aluminium housing has the metric screw threaded type.
Yes the plastic housings tops all look bowed, or scewed down face to face. The Al one was more or less face to face with the same sized sealing ring.
My conclusion was the sealing ring was not deep enough to give a good seal under all working temperatures, and the slight bowing/face to face when heated caused an irritating weep. I looked at a bedding of RVT sealant for the seal ring which gave 0.5mm additional height on the seal, and an addition backing ring seal (o ring) 58mmx 3mm to raise the sealing ring and give more height for compression of the silicon seal in the groove. This was the option I went with for the replacement on the XF SC. in the AL body. On reflection I think the root cause is the sealing ring being too short. The top cap and the three M6 securing screws should be man enough to compress the sealing ring if deep enough to prevent bottoming out/fave to face on the top and body.
I would change the fitting to the water pump to brass and remove the small bore plastic pipes with re-enforce silicon hose, thus removing the plastic fittings altogether.
Originally Posted by bydand
Sorry forgot about this.
Just some quick feed back after opening up various Plastic Thermostat housings.
Original JLR used removed leaking at 65K date stamped (2012)
New Ali Express OEM copy.
New original JLR old stock AJ812976 (2012) on bag label, and stamped 4-2015 on body, and pin stamped 15-8-2015 on the coolant inlet.
Alloy Thermostat housing ( DNPINP)
New DNPINP Alloy Bodied Thermostat housing.
All opened up and inspected internally.
Comments.
All plastic Housings. made up of 9 parts. (3 x torx screws =1 item)
Plastic top cap secured with three coarse thread Torx T20 screws.
On removal of the top cap, with the Dia 14mm x 1.5mm steel spring by 55 mm long acting on the inside of plastic housing of the larger spring seat guide.
The inner larger spring carrier acting on the top of the Dia 43mm x 3.5mm thick by 54mm long spring.
The larger spring sits on the seat guide.
On removal the thermostat accessible and can be removed. stamped rating 95deg C.
The thermostat Has rubber bonded on the upper and lower sealing surfaces.
The brass bulb acting internally on the stainless steel pin, which exerts a force down on the lower housing pocket and a force up the large spring carrier against the spring force.
By dropping and increasing the temperature in water, from an initial thermostat length of 48/47mm the pin moved to 52/54mm free length.
Original JLR 2015 seal:
The sealing ring installed in the 4.7mm groove of the thermostat body is 5.5mm deep OD 63mm , id 57mm with locating spigots inner and outer to centrally locate.
the groove is OD 63.7mm id 57.25mm by 4.7mm deep.
Other seals were of a solid rectangular sections, including the original 2012 JLR seal.
All top caps were screwed down to the body face to face.
Alloy Housing. DNPINP
As above with the solid rectangular slightly narrowing vee shaped seal at the base into the housing body.
The securing screws are Torx head T30 x M6 thread.
The internals being the same including the sealing ring, and face to face top cap securing.
In Summary,
There would appear to be very little difference between all the variants of plastic and Alloy thermostat housing.
The weakness would appear to be in the sealing ring and material longevity.
With the aim of improving this, I have included an additional backing viton O ring at the housing base id, 58mm x 3mm thick. To give better sealing, (if that is the word) and 6mm of compression in the 4.7mm groove.
02-21-2022, 12:45 AM
5.0 XKR Thermostat Replacement
