Hi all,

I've experienced little heat from this car since I bought it last March. It's truly not a big issue as I leave in Florida. Since I plan on driving the car up north in December I'd like to have a tiniest bit of heat to keep from turning into a human-sickle.

So, I decided to do a full cooling system service (I'm a preventive maintenance fellow by nature). I replaced the water pump, the thermostat, all the 10 thousand rubber hoses and the pressure cap. I did not replace the nylon lines as they looked perfect. I flushed and reverse flushed everything separately. The amount of 'crud' that came out of the heater matrix made me hopeful that I had found the cause of the no heat condition.

Unfortunately, the no (really little heat) condition continues. The coolant temperature is right at 84 C and the large diameter hoses to/from the radiator are hot to the touch. About all I can think of is that the coolant pump that supplies the heater is non functional. Is there a way to test this pump in place?

Thanks for any suggestions...

Take care,

 

This motor is on all the time and the brushes do wear out. Normally you should be able to hear it quietly running and feel small vibration when the ignition is turned on. It is back against the left hand side firewall
They can be replaced with some effort if you remove the pump and disassemble the motor. It is a trick getting it back together again. There are a number of posts on that.
https://www.jaguarforums.com/forum/x...-brush-115220/

 

OK thanks. I have a spare so I think I'll rebuild that and install it...

Thanks again...

 

Hi Bruce
I also have 01 XJ8 and have some heating system issues.
I have to put the climate control into the dash vent operation and hold down the red temp button until the display Hi (over 90 temperture level) to get a lot of heat. It also helps to turn the fan all the way up to its max.

If I try to use the Auto button (automatic heating) then no heat at all.

I ordered MNC6551BC Sensor Aspirator motor (INTERIOR AIR TEMPERATURE SENSOR CLIMATE CONTROL, also the Outside Air Temp Sensor (located in the front end grille).

I will let you if changing the sensors fixes the heating issues.

Jim Lombardi

 

Thanks Jim...that's solid thinking. I put the system in HI and the heat improved very slightly. Turning up the fan speed actually made it seem cooler!

I took my spare coolant pump apart and found one of the two brushes missing and a pile of carbon dust. I'll replace the brushes and pop this pump into the car and hope that at least that is not the problem...

Take care,

 

Bruce
When you press the red (more heat) pushbutton up to the Hi on the display, try all of the different types of vent options (one points only to Face, others - point to Face & Feet; to Feet only; to Defrost & Feet) to see if you get more heat or no heat.

also take your car on a trip for 15 to 20 minutes and try the operations mentioned above while you are traveling (do not try it while you are stopped).

Let us know what the results are.

Jim Lombardi

 

The pumps and valves don't like crud ... some of the mismatched coolant causes problems.

The system has a self test and will give some error codes -- give it a go. They don't list it but I think 14 is a bad connection to the engine temp sensor -- through the dash.

 

Ok,here's an update...

I changed out the coolant pump...the old one ran intermittently on my bench. I refilled and bled the system..ran it to operating temperature and made sure both rad hoses were hot. Topped off the reservoir and went for a drive. Initially there was no heat and I was a bit ticked...I expected the pump to work. After about 10 miles on the highway I was rewarded with good heat...very good heat...and was able to switch the airflow around and had hot air at all outlets. Then, just as sddendly, it went cool again. Not willing to call it a day, I kept going. The heat eventually returned and it works as Per normal. I didn't try other temp settings..I just left it on Hi.

Perhaps I dislodged something..I don't know. But I'm happy with the capability to make heat!

Thanks for all the help so far!

 

Thanks very much for this..I'll give it a try right now!

Take care

 

Yeldogt -

I ran the panel diagnostics and found 4 codes. I had the 23, 44, 45, and 46 present. Those in the 40's refer to sticking servo motors for the defrost, etc. but they aren't sticking...they work normally. That had me thinking that the codes might have been caused by the intermittant electrical fault that I had months ago..it set phantom codes in the ECM so why not in the climate control? I cleared the codes and rescanned...0 codes. Maybe this it!?!

Thanks again...

 

Lots of strange things can happen with voltage drop in the x308 -- best to clear codes and check to see what comes back. The code will store if detected once.

In many cases the system can check the sensors correctly -- so replacing those without a code is ill advised -- the pump is a weak link .. the valve a bit less so. I would make sure the pump is working correctly ... it acts as an injection pump -- it does not run all the time. Same with the valve. I would run the car for a bit to see what pops up.

I tell people over and over again ... if you own a car from new or you purchase a car that has been properly dealer serviced ... use the factory fluids. I have two of these cars -- and know many many other owners from new .. we have all learned .. don't mix fluids .. stick with the factory fluid ... spending $20 more one time?

 

My 01 x308 heater issue has always been related to clogged heater core. Third fall season in a row I had to perform a flush/backflush of the heater core. Always got my heat back after that. I use correct coolant, but can't speak for previous owner(s).

Cheers

 

Could as well have been air pockets moving around as needed to bleed properly.

 

Went out this morning....a cool 45F here in Florida...and the system worked perfectly. I cycled through all the positions and had airflow where it should. I lowered and raised the temp settings and while I didn't measure e temp of the output air, the system did respond with warmer and cooler air as appropriate.

I rechecked the codes and found 0.

Thanks for all the help!

 

Thanks for this. As I mentioned in the first post, I'm a preventative maintenance guy (I had an XJ12 and without pm that old girl would just plain break) and a stickler for the correct parts and fluids.

I did install the rebuilt heater pump so I should be good there.

I really appreciate all the help!

 

"I'm a preventative maintenance guy (I had an XJ12 and without pm that old girl would just plain break) and a stickler for the correct parts and fluids."

BW ............ have been around Jaguars all my life .. I understand what you are saying


With more and more plastic parts in cooling systems -- the possibility of problems is ever lessening. The germans have one theory the Japanese another -- but the various coolants have particular properties and the components sourced accordingly.

Glad it is working!

 

As not to create a new post, while everyone is still here: my pump is working, but I doubt about my valve.
How can I check this one while installed?
Will it switch with the engine off/contact on, or do I need an aux power?
I am afraid I might not hear any switching if the engine is running.

Eric

ith the engine not running