2007 XK with 80k on it. I've noticed my fan has been running a lot more than usual and for a while after I turn the car off. My wife was driving it and said the engine over heating light came on so she stopped, let the car cool off and then drove home.(less than a mile) I was short about a pint of coolant. My credit union put a extended warranty on the car for me so I took it in last week. They just called me and said that it's leaking coolant were the upper hose is attached the radiator. He said the radiator is cracked there. This is the first car in a long time I've taken in to have it worked on instead of myself. That seems like a strange place to have a crack in the radiator. He then quoted me 1100 for the radiator plus labor. Is that a normal place and is an aftermarket radiator if I do need to replace it ok?

 

Very strange. If it were me I'd turn up at the garage unannounced and want to see it for myself. If they start to fob you off then something is fishy.

 

Jim, that's what I was thinking.

 

You stated you have an extended warranty and if the radiator is covered, what do you care?

Get the Jaguar fixed properly.

If the extended warranty won't cover the parts and labor, then you know you have a very crappy extended warranty policy that is probably useless to you in the future.

 

Rich, it doesn't cover a radiator. It does cover my engine and trans and was thrown in for free by my credit union for being a good customer. That along with 1.95 financing made it a good deal. I guess I'll bring it home and look at it myself. I'm not losing much coolant at all so I wonder how hard the so called crack will be to see?

 

I wouldn't expect to be overheating when just down a pint of coolant.
Sounds like either a stuck thermostat or a bad water pump.
If you've got an OBD-II transmitter, and one of those apps on your smart phone, you can monitor the temperature yourself.
Mine normally sits at about 199 degrees while driving, and may go up to about 205 when sitting at a traffic light on a hot day.
Once your car get up to operating temperature, you might be able to see the leak, if there is one.

 

Agree with kj07xk, a missing pint of coolant is not going to cause an overheating problem, water pump or thermostat is more likely the culprit.

 

Would a bad water pump cause my fan to keep running after the car is shut off? I'm going to pick it up today. I'll run by and rent a odb II.

 

If the car is too hot, the fan will run.
Make sure the OBD reader will report the temperature if you're going to rent one. Getting a wifi or Bluetooth model that will pair with your phone is a good investment (under $50), along with a free phone app to read it (get the right OBD-II model, Bluetooth for Android, or wifi for iPhone).

 

How can I determine if it's the water pump or Tstat?

 

Guess I would try this:
When the engine is hot, touch the upper radiator hose (if you've got an infrared thermometer, try that), if the hose is hot, its probably the water pump, as the thermostat is open and heating the coolant in the hose, but it is not being forced through the radiator to cool it.
If the upper radiator hose is not hot (or as hot as one would expect in a hot engine), its probably a stuck thermostat, not allowing the hot coolant to flow toward the radiator.
Sensing the heat in the radiator hose is subjective, unless you're using a thermometer, so there's no guarantee this will isolate the issue.

If it is the thermostat, replace the housing as well, as it is plastic and prone to failures of its own. I replaced mine last year, with about 40k on the clock, when my thermostat failed (stuck open, so I was getting an 'under temperature' OBD error code, with my check engine light on).

 

Even with the engine off and not running the fan, which is electric and computer controlled, will continue to run until the coolant temperature has dropped to the preset level. That's normal and can take several minutes depending on the outside temperature.

Modern aluminum radiators typically have a plastic upper hose fitting that, over time, is prone to cracking and leaking due to expansion and contraction. Look for tell-tale signs of dried coolant to pinpoint the source of the leak. If that plastic neck is cracked, it is not a serviceable part and your radiator is toast.

 

Upper radiator hose is pretty hot after driving about 3 miles. I'm just not sure how hot it should be.

 

Now check for visible leaks around the radiator neck and look for any possible leaks around both the water pump and the coolant reservoir (they have been known to crack and leak). Lastly get that OBDII reader to watch the engine temp.

A pint loss of coolant over time shouldn't be a worry but the engine temp rising definitely is. Tour issue may be nothing at all, could be something very simple, or could retire a new radiator, WP, or thermostat. If it does require parts I'd highly recommend that you purchase them yourself (even check Amazon for the oem parts or our board sponsors) then have them installed you'll save yourself quite a bit of money

 

Its a pretty subjective test, so yeah, if you're not familiar with how it feels when its operating normally, you may not be able to distinguish which is at fault at this point.

Engine overheating is not something you want to play around with too much, as it could do serious damage, but did your 'engine overheating' light come on during your 3 mile drive? Did you have an OBD reader that could report the temperature to you?

Do you know if either (or both) the thermostat and/or water pump have ever been replaced in the car? (If you have the service records.)
At your mileage I would consider replacing the thermostat and housing, if it hasn't been done before (like I said, I replaced mine at ~40k, due to a stuck open thermostat). The water pump has plastic impeller blades, and if you search this forum you'll find others have had this break on them.

The cost of these parts isn't bad (much less than you were quoted for that radiator, ~$130 for the thermostat and housing, and I see water pumps in the $25 - $100 range on the web, but I can't comment on which one is better), so I would consider buying and replacing both. Inspect and test the original parts, and whichever one is still functioning, keep it as a spare, just incase you get a failure later. (If the water pump impeller broke, it will be necessary to make sure all the pieces get removed.)

 

KJ, no it didn't overheat on my drive home. I'm headed to get the scanner this evening so I'll hook it up and test it around the area I live in. I'll go ahead and replace the tstat because I know it's something I need to do. I replaced the one on my Rover right around the same mileage and for no other reason than I wanted to.

I have no service records. It was the one negative thing about the xk I bought.

What's the range for my temp that I should be looking for?

 

Mine normally runs between 197 and 205 degrees (F). Usually 199 while driving.

 

what's my shut it down temp? I don't want to worry about messing anything up. I changed out the tstat yesterday.(for those that are wondering it's about as easy as it gets. The hardest part for me was getting the clamp on the hose to the tstat housing back on) I'm going to drive it and monitor temps today but don't want to come close to overheating it.

 

My 2012 XKR runs about the same. 200*F +/- 5* in normal outside temps between 25*F-95*F

 

So that seems to be the 'normal' range. If you are shooting higher (210+), you've still got a problem, and should look at the water pump replacement.
You could also test the old thermostat to see if it opens in a pot of near boiling water, just for piece of mind, if nothing else.