Can this process be done by a DYI or is it best by shop? Looking at the manual says nothing (that I can find) on the process. I also checked the "sticky" any help or push in the right direction would be helpful. As always thanks all. 1998 Xj8...45K. Is this a preventative move or do only when needed?

 

Several members have written about doing this, so a search should turn up something. But the process is basically to clamp a garden hose with the end cut off to the heater outlet, and another piece to the inlet to avoid giving the engine a bath.
I would not open the faucet all the way, at least initially.

Considering the difficulty of draining the coolant first and the risk of messing with old plastic parts, I would only do it if necessary.

 

Thanks RJ. You answered my question. Think I'll hold off until necessary, hopes would be in the summer.

 

DIY for sure - did it twice already (two winters in a row) and about to do again before cold days. Access requiring a little bit of dexterity, but not impossible

Cheers

 

What is the status/ history of the coolant replacement in the car? Do you know what is in it?

Your model year would have been factory filled with the old coolant. Jaguar went through two revisions before the orange in 2000-2001 (I don't have the changeover VIN/date in front of me). I can't remember if the flushing procedure was described or simply linked to on the TSB for the coolant. The old coolant had to be completely flushed prior to adding the new formula. Do a search and you will find the TSB. I believe it was yellow first - then sort of a blue -- then orange. My long gone 1998 had the changeout in 1999-2000

The current Jaguar orange is a modern long life coolant... I had mine changed out at the 5-6 year mark and again about 4 years later. Both times it was very clean and this was my experience with my other one. I did a simple dump of the system and refilled with the Jaguar coolant and distilled water. It gets enough of the old out and if you are using the same coolant no benefit in flushing. We did pass a gallon of water through the radiator to see if anything came through.

You don't want to mix coolant types and obviously want the correct formula. Lots of opinions on this. I stick with the OE and distilled water when I change out my cars -- with all the valves, pumps and various metal components I don't want problems -- the parts are a lot more expensive then the coolant/ water ... and they don't tolerate much buildup before you have problems.

 

I was sorta hoping for a process breakdown, couldn't find a thread on it yet.

 

How long ago was it changed?

How about this:

 

No record of change. Didn't think to look a TSB. Thanks yeldogt

 

OK -- How long have you owned it.

Color of coolant.

Do you know if it was dealer serviced? If so ... did you contact the dealer .. and ask when changed?

I mentioned the TSB?

If you have some of the answers .. the solution can be as simple as dumping some coolant. I own a car that was my fathers .. from 1971 .. regular coolant refreshes .. never been flushed.

So many cooling system problems are caused by well meaning owners not doing simple maintenance .... and not keeping the same coolant.

 

I have owned it for two years. Never changed on my watch. Old owner said all fluids changes at dealer. Can't verify. Interesting though, I bought all the parts for second gen tensioners, after I tore into it, found they were already upgraded, So I thing the prior owner had quality service completed regularly. Maybe flush was completed...no records though. My color is yellow. I have brand new purple stuff I was going to use last summer to replace...got lazy and figured I'd wait. I did print out the TSB, thanks for the tip.

 

I guess you don't have any records for the car? Was he the original owner?

The dealers would have used Jaguar coolant -- this has been orange since 2000.

My 1995 x300 was yellow/ green - I don't think yours would have been originally filled with either .. they had another one that caused problems just prior to the orange.

Reading the TSB -- you can see the lengths that Jaguar wanted the dealers to go through to get out all the old coolant. You don't want to be dumping in another fluid without trying to figure out what is currently in the car.

As I said above ... with the proper coolant (refreshes) the system is very reliable. The pumps, valves and thermostat don't like any buildup.

 

Hi,
What is the air purge breather cap mentioned in this TSB?
Thanks,
Dan

 

DanR: Good Question! At first I thought they were talking about the tank cap -- but then they mention it by name.

On the XJR's you remove a aluminum cap -- I would have to look but I remember it was an internal hex. I thought it was for the supercharger cooling? -- maybe not and on the NA also. Ordered a seal or "o" ring for mine -- funny how I can't remember. I don't have the car with me to look. The TSB does not mention a seal in the parts required.

With this cap off it was easy to see when the coolant had filled the engine -- and it allowed the air to escape.

 

DanR
The last time we had our Indy mechanic change the coolant in our 2001 XJ8, after he refilled the system with coolant, he left the cap off the coolant expansion tank and squeeze the radiator hose that is attached to the radiator left front position.

As he keep squeezing it, I could see the air bubbles coming up in the top of the coolant expansion tank.

Jim Lombardi

 

That's how I do it, also. No air locks that way. The R types do have a cap on the intercooler that should be removed to get the air out. 19mm hex key.

 

Bigcat777 - I am overdue a write up of flush/backflush procedure. Actually promised it for a few folks in the forum. So happen that I am planning to do so this week-end so will do my best to document. Temperatures have dropped this week in Austin, TX and have been without heat !! Same as every winter, I need to unclog. My model IS an orange coolant required, and have only been using that - but who knows what has been used earlier in its life....

Cheers

 

The reason that I ask is that the heater has packed up again.
Two years back, I back flushed the heater matrix and got it going again.
Now, no more heat!
I find it hard to believe that the matrix is clogged up again.
I wonder if there is an air pocket? And the idea of a purge valve to fix it sounds attractive!
I have replaced the bushes on the heater pump motor but I must check that it is still running. Is there a fuse for it? I will also check for motor running with a stethoscope.
There is also a slow coolant from somewhere. I can smell it and the expansion tank goes down over 2-3 weeks. I was thinking of adding a UV dye to the coolant to help trace it.

 

DanR
I think there is no bleed valve on the XJ8 models, at least none that I could find by viewing (and browsing the internet) the radiator and the thermostat tower/crossover pipe.
That is why our mechanic sqeezes the radiator hose.

Jim Lombardi

 

Dan:
I doubt very seriously that you developed a bubble after two years! The matrix is, by far, the smallest passage in the cooling system. On my wife's XJ8, I backflushed the matrix several times, then it finally would not clean any more. So, I had to flush the entire system (removing many of the large hoses and the thermostat) , then I replaced the matrix, which is a major PITA on RHD cars. Refilled with Dex- Cool. No problems in the years since.

I had a similar experience on my X-300 with the same matrix.

I am convinced that the standard Green Prestone I was using to refill after previous flushes caused some white powdery looking stuff to precipitate out of the mixture with the original fluid. Until I got it all out of the system, I continued to get plugging. I know the Dex Cool is not the recommended fluid, but I have had zero problems after using it for many years in my Jags.

 

Perhaps i could save you the effort and also inform other forum members
with cooling system issues ;o)
If you would care to look at the following site, you will find quite a selection of o useful information:

XJ8 COOLING SYSTEM PROCEEDURES Photo Gallery by Max Heazlewood at pbase.com

this should help members.