Hello All,

1998 XJR

First time poster, so sorry if I am blatent newbie ...

I have been through this site and searching for someone who may have/had the same issue I have now with an overheating motor. There are a few topics similar but I thought I would just ask. Chronological history of events:

• Issue began .... Last week, sitting in traffix with AC on and motor overheated
• Towed home
• Found a crack in overflow expansion tank where coolant was spewing out. I thought it was an easy fix ....
• Bought used expansion tank and new thermostat and installed yesterday. Thermostat was installed exactly how last one came out, so Iam 99% sure it is not backwards
• Filled coolant and went on test drive
• Care was great for 10 miles, then, immediately overheated when stopped at second stop light
• pulled over popped hood and squeezed coolant hoses, very gummy with no pressure (there is another leak leading to no pressure in cooling system) I can not visibly see where the leak is
• then .... listened to the hoses and it almost sounded like the coolant was litterally boiling inside
• steam and pressure was coming up out of driver side engine bay diectly over driver side tire well, but under power sterring bottle area. I could not see from the top
• I jacked the car up to get underneith to see leak but, could not see anything from under exept for the chronic drip running off the 2nd coolant resevior (I think that what it is...) under engine bay a next to driver side wheel
• For sure the leak is coming out of driver side of motor but not from any visible coolant hoses upper or lower

I hope someone can help .... my fear is a blown head gasket (water boiling) but I am optimistic is is something easy to fix.

I very much appriciate all your expertise or thoughts on what part it could be, and then any advice

Warm regards,

greg

 

moved you to the specific X308 section, just for you. though this is a 'genera' question, you'll get MUCH more exposure over here. best of luck!

 

My standard reply to coolant leaks is to rent a pressure test kit from one of the national auto parts stores. Pump it up cold and it will be evident where the leak is.

You could be describing a failed thermostat that has partially blown out a hose connection. The pressure test is a lot safer than risking overheating again. Incidentally, I bought a used reservoir and found that it leaked in exactly the same place my failed one did.

. . . and welcome to the forum!

 

Hi
The lower tank is the Recovery Tank.


Jim Lombardi

 

It sounds like your cooling system is not holding pressure and when it heats up the coolant overflows from the reservoir into/from the recovery tank. I would do as Test Point said and do a pressure test and see where it is leaking from - if it's not the reservoir cap. Also, make sure the coolant lines from the reservoir are not swapped. The one on the left side goes to the radiator the one on the right crosses over (or under)and goes to the recovery tank (as seen sitting in the driver's seat - LHD).

 

Thank you for the replies.

JimmyL - thank you. I did have the coolant lines swapped. I appreciate the insight!

test point - I will do this test on Saturday and let you know how it goes. I'll do it cold like you said and listen or look for the leak that way.

My gut is the the expansion tank (thanks jimlombardi) has a leak. We'll see.

Thanks guys.

 

I think I may have found the original issue ....

my fans are not coming on at all. both upper a lower are not working. I bought a radiator fan switch on ebay ( Beck/Arnley 203-0168 Radiator Fan Relay | eBay ) and can not find where it goes. I've also checked fuse #12 and #14 in larger fuse box and they seem to be fine. I also found the radiator fan control module next to expansion tank up front of left hand wheel, but do not know what to look for or how to test it.

Where does teh fan switch that I purchased go? Thank you so much ...

 

Be wary of that Beck/Arnley relay. The description does not say whether it has a built in damping diode. Most relays found on your model employ a damping diode to protect the solid state coil driver circuits. No diode == destroyed driver circuit. If the relay has a diagram on it, look for the diode across the coil.

There are three things you can do that will help you immensely ...

1. buy a digitial voltmeter from Radio Shack, it will let you test circuits without guessing

2. download the electrical diagrams because the accompanying sheet on each page tells you where the components are located for each sheet. the link(s) can be found in the various stickies

3. download JTIS because some of the sections related to electrical repairs have diagnostic tests that you can perform

 

I had the same problem a year ago. Cost me $7000 when all was said and done at the dealer. Fans stopped working, had slight coolant leaks that eventually had the need to replace ALL the hoses. If indeed you do have to swap out the hoses and you have to take the supercharger off... take my advice and use that opportunity to send it out to get ported. Regardless, check your fans, battery, hoses.

Coventry West should have all the parts you need.

 

Hi gocallahan
If you need the free JTIS download, use this weblink to the download thread (go to post#1):

https://www.jaguarforums.com/forum/x...uctions-54640/

Also read the other posts in the thread about installing (64 bit operating system issues) and using JTIS tips.

Jim Lombardi

 

Thanks for the great replies! What an awesome forum this is.

I'll download the JTIS and go from there. Thanks jimlombardi!

 

Thanks for your feedback , this is why the forums are for