Water Temperature Fluctuation
#21
Senior Member
1. Do you think it would be useful to use a handheld IR thermometer on the radiator hose to the right (passenger side) of the outlet tube, to determine the coolant temp before it enters the radiator? That would help to confirm or deny the temp readouts provided by your aftermarket gauge.
2. Is it possible that the thermostat is not fully opening, and needs to be replaced? I recognize the XKR has a metal outlet tube vs. XK which has plastic. In the case of my 2007 XK, one of the two tabs holding the original thermostat to the cover had broken, and it appears the thermostat would not fully open.
3. With the high ambient temps here in southern AZ, I have placed an order for the nine XK engine/heater coolant hoses and will replace them soon, as well as the coolant pump, tensioner and serpentine belt. I'm not interested in stressing the engine in the event of a hose failure, especially since the layout of the engine in the engine compartment means it is almost impossible to see a leak until it becomes catastrophic. Its not easy to inspect the coolant pump unless the outlet tube is removed, as another example. The engine under cover can hold substantial fluid before any of it leaks out, since it has ridges cast into the cover.
2. Is it possible that the thermostat is not fully opening, and needs to be replaced? I recognize the XKR has a metal outlet tube vs. XK which has plastic. In the case of my 2007 XK, one of the two tabs holding the original thermostat to the cover had broken, and it appears the thermostat would not fully open.
3. With the high ambient temps here in southern AZ, I have placed an order for the nine XK engine/heater coolant hoses and will replace them soon, as well as the coolant pump, tensioner and serpentine belt. I'm not interested in stressing the engine in the event of a hose failure, especially since the layout of the engine in the engine compartment means it is almost impossible to see a leak until it becomes catastrophic. Its not easy to inspect the coolant pump unless the outlet tube is removed, as another example. The engine under cover can hold substantial fluid before any of it leaks out, since it has ridges cast into the cover.
2. It is possible that the thermostat is not fully opening. Since the car cools fine under load, while moving, I think the thermostat does fully open. My guess is the water pump flow rate is not sufficient at idle to keep it as cool as I would like it. It should not be a problem until the coolant starts boiling somewhere a little over 250 *F. That is probably why Jaguar triggers a warning in the mid 240's.
3. At 10+ years in Arizona I think changing the coolant hoses is a good idea.
I am not going to get too worried about what I am seeing now. I am using those numbers as a baseline and will worry if they deviate very much from the baseline. I got the OBD temperature gauge to serve as an early warning if/when the water pump fails.
Patrick, If you are in Green Valley you should look into the Jag Club of So. Az. - JCSAZ.com There are a few members from Green Valley. We do monthly drives, an annual concourse, and a few other events.
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Sean W (07-13-2017)
#22
Senior Member
1. I am not sure exactly where the temperature sensor for the OBD measurement is. It may or may not have good correlation to the radiator coolant inlet...
Patrick, If you are in Green Valley you should look into the Jag Club of So. Az. - JCSAZ.com There are a few members from Green Valley. We do monthly drives, an annual concourse, and a few other events.
Patrick, If you are in Green Valley you should look into the Jag Club of So. Az. - JCSAZ.com There are a few members from Green Valley. We do monthly drives, an annual concourse, and a few other events.
Thanks for the info about the local Jaguar club!
#23
Thread Starter
|
Veteran Member
Another tidbit. It 76*F in my garage this morning around 11:00am. Outside it was 84*F . I started the car and the WT was 76*F and it rose to 100*F just as the idle went from Open loop to Closed loop (also same time to drop the top) . I put it in reverse and backed out of the garage. It was at 168*F by then. So as I drove out of the driveway it was at 185*F and by the time I was a 1/2 mile away it was at 198*F. Ran at 195*F to 205*F for the next 2 hour drive. Just an FYI
#24
Veteran Member
#25
Veteran Member
Aren't all of us dumb bells with a 2010 XK or later with no guage and none of the technology here on this forum to measure temperature better for it? Is this not over the top for our "Luxury Cars"? I know this forum is for enthusiasts....But it does take the air out of the balloon for enjoying and owning our fantastic cars to be overly concerned about the engine temp to avoid a blown engine/head gasket etc. Yes?
#26
No.
Time has proven that most owners don't know how to correctly interpret coolant temps and frequently don't take the correct action.
The number of instances where the coolant temp has become dangerously high without a gauge reflecting the condition is very small. Instances where a warning is present- but ignored is the real problem.
Oil pressure or battery voltage/amperage indication is not much different.
Time has proven that most owners don't know how to correctly interpret coolant temps and frequently don't take the correct action.
The number of instances where the coolant temp has become dangerously high without a gauge reflecting the condition is very small. Instances where a warning is present- but ignored is the real problem.
Oil pressure or battery voltage/amperage indication is not much different.
#27
Thread Starter
|
Veteran Member
Aren't all of us dumb bells with a 2010 XK or later with no guage and none of the technology here on this forum to measure temperature better for it? Is this not over the top for our "Luxury Cars"? I know this forum is for enthusiasts....But it does take the air out of the balloon for enjoying and owning our fantastic cars to be overly concerned about the engine temp to avoid a blown engine/head gasket etc. Yes?
#28
Veteran Member
Aren't all of us dumb bells with a 2010 XK or later with no guage and none of the technology here on this forum to measure temperature better for it? Is this not over the top for our "Luxury Cars"? I know this forum is for enthusiasts....But it does take the air out of the balloon for enjoying and owning our fantastic cars to be overly concerned about the engine temp to avoid a blown engine/head gasket etc. Yes?
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ralphwg (07-17-2017)