Been a while since last posting but...my MY06 XKR came close to overheating. Had the infamous "low engine coolant" message show up and a slight smell of coolant from engine. Took it to the local dealer. They ran a diagnostic and discovered the sensor off the expansion tank was bad. Got the green light for the rest of the system. They offered to replace tank (big money). Said no and ordered the part online from another dealership (great price) and installed myself. Clips and removing the tank was a PITA - but done. Filled tank to spec. Started up the car and realized the bleeder hose coming off the tank had a small leak between the rubber hose and the plastic hose. Replaced the 2" hose and used a different clip (obviously cheaper than replacing that entire bleeder hose assembly!). The 2" rubber hose was free from a local parts store (not enough to charge). Fit well. After replaced, started the car and let it run for about 30 min. Did not watch like a hawk. Next thing I know, the temp gauge was running way hot. Possibly overheating. Turned off, let sit for several hours to cool down, started back up then pulled back into the garage. Didn't seem to have a problem with startup but did not let run. Immediately pulled in garage and shut down. Haven't done anything since. Now before replacing the tank and the 2" section of the hose, there were no problems other than the low coolant message. When left the dealer, service manager stated I could drive it without an issue. I would just have to deal with looking at the message and red light. Need some help. I've looked all over the forum and can't find a solution. Anyone have any ideas? Could bleeding the system for air help? Change Tstat? I've seen these and other ideas. Your thoughts?

 

First you need to look in the tank and see if it's filled, if so then most likely a water pump or tstat. The light by itself if level sensor is bad wouldn't cause a overheat. Are the fans running with the AC turned on? A off chance is the water temp sensor but I'd suspect that last. You can check it with a IR reader (there are other threads on this) maybe borrow one.

 

QUOTE: 1. 'my MY06 XKR came close to overheating. Had the infamous "low engine coolant" message show up and a slight smell of coolant from engine. Took it to the local dealer. They ran a diagnostic and discovered the sensor off the expansion tank was bad....green light for the rest of the system. They offered to replace tank (big money)....ordered the part online from another dealership (great price) and installed myself....'

2. 'Started up the car and realized the bleeder hose coming off the tank had a small leak between the rubber hose and the plastic hose....Replaced the 2" hose....started the car and let it run for about 30 min.'

3. 'Next thing I know, the temp gauge was running way hot. Possibly overheating....'

4. 'before replacing the tank and the 2" section of the hose, there were no problems other than the low coolant message....' END QUOTE.

1. Was the 'low engine coolant' message, red warning light, and the smell of coolant, the only initial indication of the car coming close to overheating? Did the gauge, for what it is worth, go into or approach the 'redline', when you received the FIRST 'low coolant' message and warning?

2. This ties back into #1, of course the dealership is going to diagnose a problem requiring an expensive replacement, but I believe your problems all stem from the leaking hose you discovered, and was your initial problem all along. The sensor on the expansion tank is sensitive; when I bought my 2003 XKR, the red light was lit and the 'low coolant warning' text displayed. It took less than 2 ounces of coolant to turn off the warning light and message. The coolant 'full' level is all the way up the neck of the reservoir. Due to the slow leaking hose, and smell of coolant prior to the warning message, the sensor was doing exactly what is was designed to do, alert you.

3. Was the temperature gauge in the 'red', fans blasting higher than you have ever heard them run?

4. If the gauge was not in the 'red' on the first occurrence of the warning message and the fans were not blasting on high, you would know if they were, you were most likely not overheating. The low coolant sensor is sensitive, down to an ounce of liquid before setting off an alarming message. The slow leak in the hose drained it enough to trigger the sensor, and produce the smell. Jaguar employed a scare tactic to try and make a buck. Unnecessary replacement of the tank introduced new problems into your cooling system, and I believe the only actual problem other than the original leaking hose, which as you have stated, 'hose was free from a local parts store (not enough to charge)'. It may be that you have introduced air into the system, or coolant has saturated wiring or an electronic component. Search for 'coolant system bleed procedure', as I have heard that air can become trapped in the system and cause major problems.

 

Love how the dealer said don't worry about the red light. HA HA HA IDIOTS!
You don't say what year the car is, the mileage????

 

This could be a Tstat issue to a WP issue to another hose that has been leaking off fluid slowly till you got to a low reading. Maybe a pressure test of the system is in order? Did the dealer even do that?
I have to say that the few time I went to my local jag dealer with the two xk8 cars I have owned I always got the vibe that they didn't want to help me with my issues.

 

Thanks for replies all

When the low coolant light came on the car was fine - other than a slight smell of coolant. Was already heading to dealership To pick something up. Was told change the tank. Did so. Started car up with no red light but slight smell of coolant. Possibly from spilling during changing tank. Noticed leak off bleeder hose. Replaced 2" rubber section. Started up again with no leaks, no red light, and gauge indicating normal operation. Needle warmed up to middle of gauge. Let run for 30 min and needle approached redline. Shut down and let cool off.

 

I did state model year - 2006 XKR

 

Thanks brgjag

Not sure if the dealership did a pressure test. I don't think so but will call. I don't have my paperwork with me.

 

Thanks jamdmyers - both tanks were full. I think ac was on but fans were certainly running. I'll check around for the reader.

 

Air lock after working on cooling system not unusual. It hepls to squeeze the radiator hoses repeatedly with the cap off the header tank, but watch out you don't splash coolant out and on coil cover.

 

i had similar when I first had the car after taking out the heater pump for repair. Try a coolant flushing additive and fresh coolant poored in very slowly with the car on level ground. worked for me, no red lights or warnings

 

Just 'burp' it. The 2" plastic to rubber hose interface was your only and original problem. It leaked onto something hot and produced the smell. The sensor was activated by the slightly depleted tank due to the leaking hose, all normal. If they had actually been looking around that area, they would have and probably did, find the leak; they just figured they could make a buck off of you. When you took matters into your own hands you introduced air into the system, and spillage around the immediate tank area. A new section of hose and a few ounces of coolant would have solved your original problem without exchanging tanks and introducing an air lock into the system. So again, 'burp the system'.

 

Thanks all. I'll try to burb the baby!

 

mm--I've attached a handy guide for coolant change which has a section regarding adding coolant and burping the system on the xkr.

 

Mountaincat - wow what a guide! Thanks, will try this evening...

 

Finally got around to fixing this issue. Squeezed all air out of hoses and all is fine! Thanks for all the help. Also - was informed by the dealer a few days ago that the MY will automatically bleed the system.