First post. Newbie to jags. Do not know a ton about cars also, so please be gentle. I read a lot, and I'm pretty good at putting things together.

I did a thorough search on this forum and it seems that my problem is shared in that I have had a small drop in engine coolant over a short period of time--more than I am comfortable with. I have an XJ8 VP, 1998 with around 50K miles. Just got the car - "low engine coolant" warning came on the same day (it was a little low when I checked)...seemed to go off going up hills (I read all about the highly sensitive floater in the tank, and known 'early warning' with plenty of coolant in this car), I topped it off assuming that the previous owner who rarely drove it did not check the level often so no big deal EXCEPT that I noticed the level was a tiny bit down after 200 miles. I topped it off again when cool, and it was just a little down after around 100 miles. No obvious leaks, no cracked hoses, and I do not see dried orange residue. The car runs great, and temperature is fine, with no more low coolant warnings but.....

Has anyone experienced this in the XJ8 and do these cars often need a little 'topping off'? As I understand, it's a circuit, and I should not be losing coolant at all unless there is a crack in a washer or hose and the coolant is being evaporated behind the manifold where I can't see or if it is somehow leaking into a darker part of the engine. The radiator is without rust at all.

I really would appreciate some thoughtful advice from experienced owners. Thanks in advance, guys.

 

My radiator fan runs sometimes runs for around 20 seconds after I switch the engine off (freaks my wife out)....if that helps diagnose the issue.

 

Hey, welcome to the site

You can read FAQs at the top of the page , they'te sticky . This is really a friendly forum and our gurus will gladly help you point out the right direction

 

With regards to the fans running on, it's possible you need a new thermostat, a cheap part. Also, if changing the thermostat, there's an updated thermostat housing made of alloy instead of plastic (prone to cracks). My suggestion is to replace both. Only use the orange/red coolant.
If you suspect a small leak, you could pressure test the cooling system, this may show you where it's going. It's good you're keeping an eye on it.

 

Hi Scottish Chap
Welcome to the forum.
We had the same problem when our 2001 XJ8 at just a little bit over 40,000 miles started losing a slight amount of coolant. Our local Jaguar dealer did a pressure test of the system. They found a pin hole leak that was coming from the water pump.

They replaced the water pump under the Jaguar warrantee (2 weeks before the warrantee period ended).

The leak was so small that it would not have been found without the pressure test.

The secondary timing chain tensioners (1998-early 2002 XJ8 & XJR) and the forward disk in the transmission (1998-2003 XJ8) are 2 other repair items that are possible major repair costs.

The plastic tensioners will fail if they are not replaced with the 3rd generation metal type. If the timing chain skips more than 1 tooth, it might cause major engine damage resulting in a new engine being needed.

You should contact your local Jaguar dealer to get the repair history by giving them the VIN number of your Jaguar.

Jim Lombardi

 

This engine's coolant system is famous for mystery leaks. Thermostat tower leaks under the intake manifold, bottom of reservoir leaks onto the catalytic converter, Norma connector(s) leak onto both converters, reservoir develops a tiny crack and sprays a fine mist that evaporates without dripping.

Sean B is correct, a pressure test on a cold engine is the best method of locating the problem. Your fluid loss is, indeed, too much to put up with.

. . . and welcome to the forum!

 

Thanks for the help. Quick question - does the orange/red coolant have a special name or mic, and can I get it anywhere? Thanks!

 

Thanks for the help, guys. The vehicle has a limited warranty as it was bought from a used car dealer. I am going to now ask them to reasonably investigate this. This warning light coming on same day of purchase is a bit much.

I really appreciate your help. This is an amazing car. I love driving it and it drives well. My one anxiety is that it's so beautiful with a pristine-looking engine with low mileage that there may have been something major wrong with it that made the prior owner drop it off as a used car dealership. Carfax tells me it has 35 service records (done between June and August...likely a summer car). Can I get any of this for free online or do I need to pay jag for that?

Happy 4th!

 

Any Jaguar dealer can produce an abbreviated report of warranty work but will decline to provide invoice-by-invoice service records without a release from the previous owner. That is a privacy issue as there is name, address and telephone numbers on the invoices. With that release they can print the complete service records.

I got a release and got each and every one of the invoices, both warranty and service for my car. A dealer should be interested in helping to attract the new owner to use their dealership.

The coolant reservoir should have a label as to the type of coolant installed. Orange is the usually expected color of the coolant and that should be DexCool. Lots of discussions on not mixing types of fluids.

 

Welcome to the forum!

You should not be using any coolant - so you have a problem. You need to find out what it is as you may be getting a warning of a problem that could cause you to loose a hose or other component. Whoever you bought it from should be able to pressure test.

My fans on very hot days have run on after shutdown -- so this may not be anything to worry about.

Do you have any service records?

The brake fluid should be changed every two years. Maybe a trip over to your local Jaguar dealer for a fluid change (100.00) and a once over may be in order. Checking the transmission fluid level could be done also. While you are having the work done you can ask your service writer about the selling dealer any previous work done that is in the database.

Jaguar switched coolant twice in the late 90's -- So you need to see what you have in the car and what it should have. The dealer can tell you. I always stick with the factory fluids -- the cost savings IMO does not warrant any potential problems. If you have any question about the current fluid -- I would switch it out.

Also -- do some research on the upper tensioners -- they need to have been updated

Good luck

 

Thanks for the advice, folks. You guys truly are awesome. I am a trainee doctor (think: degree minus the earning power), and so diagnosing a lot of these issues in cars is akin to what I do with the human body every day. I am just getting into cars, and could really see myself being a major jab enthusiast as a hobby. I also belong to several similar forums in my own profession, and 'give back' as a moderator to help those trying to get to where I am.

Again, I am a newbie and so some of what you mentioned (secondary timing chains etc.) is over my head. The car is obviously still drivable and I have heard jag owners say a small coolant issue like this can remain dormant for years, and then get big. Thus, I will return to the nice dealer tomorrow and ask them if they will make a reasonable effort to find the leak. My main anxiety is that they will do a macroscopic inspection like I did and say: "sorry, we don't see any obvious leaks" without doing a pressure check which is obviously needed.

Last thing: I noticed that the coolant tank cap has trouble coming off (i.e. I had to screw it around a dozen times, and it just didn't feel like it was sitting right on the threads). Does is seem reasonable that a poorly-fitting cap may explain a slight loss of coolant? Again, I stress that there is no residue around the cap and I do not smell anything odd inside the car....if that helps.

 

The cap can be difficult (very) to remove because of the "O"rings -- but the spinning you report I am not familiar with. I had a early V8 VDP and I remember them replacing the cap under warranty -- I believe some were faulty as was the gas cap on most models. You can loose coolant if the cap is faulty -- but you would see it. Unless -- I guess it is leaking into the overflow tank.

Every car has problem points: The Jaguar cooling system works very well but it has some weak points. Your model has a water pump with plastic parts that will eventually fail -- also the top of the thermostat is plastic and can fail -- all of the years have various connections that can leak after 10+ years. That's why even if they find the leak it would be a good idea to go to the dealer for some information -- you may have some of the upgrades without knowing. You want to do the water pump upgrade if it is not already done -- do all the cooling system work at once with new fluid and your good to go.

The tensioners are in the heads (valves) of the engine - with low miles you may not have anything done to yours -- but if they fail your engine will be seriously damaged. Many of the old ones have been updated -- your dealer may be able to tell you -- you may be lucky. About a 1k job if you have to do it

 

The tank definitely has orange coolant. I found orange DexCool coolant at the store, and assume it's the right one, yet it states "not for European cars". I am assuming that my 1998 VdP model was made after the take-over by Ford by that time and thus the orange, DexCool is fine?

 

Long story, but Ford does not use DexCool, as it is generally used in GM vehicles and has had a history of engine failures attributed to the coolant. Ford used different coolant in their branded cars that used the Jaguar engine (Thunderbird/Lincoln LS).

That is why many of us have flushed and changed to the Zerex G-05.

Hope that cleared up the confusion on coolant. If not, here is a link to a thread on the subject: https://www.jaguarforums.com/forum/x...onfused-47724/

Buried in that thread is the following from 'avos'. Anything avos posts you can take to the bank.

"There was a TSB about this, and VIN up to 010343 had blue/green coolant. From that point it was Jaguar D542 (yellow) coolant until VIN 042636. For some service recalls it could have been that the early cars where flushed and got the yellow.
From VIN 042636 the orange (dexcool) was used."

That's why my comment on the label on the overflow reservoir.

 

In addition to what has been mentioned earlier.

1. Are you filling and bleeding properly? There is a specific procedure to get the air bubbles out.

2. Are you checking the level at appropriate times? It should be checked with the engine stone cold. If you check it while warm, opening the cap interrupts the ability of the sealed part of the system from pulling back coolant from the expansion tank in the front wheel well. The next time the car is run to temperature, it will push more coolant into the expansion tank without having pulled any back in. The expansion tank is also referred to as a recovery bottle.

3. The second point can be greatly affected by a defective pressure cap. The pressure cap behaves differently than the old style metal caps. From tight, it unscrews several turns. It will seem to keep on requiring turns, except that the resistance is really the rubber o-ring. It takes a while to get used to unscrewing a few turns and then trying to lift it away while it still feels like it needs further turning.

 

1. Yeah, so I just learned about "burping". I didn't do it. I now know better. Please can you describe anything further that's needed other than squeezing on the rubber pipes after filling, and then filling some more. I understand this gets air bubbles out and without this you can get a low coolant level via unexpelled air but, *really*, can not doing this affect the coolant level enough that that it's making the low coolant warning light come on? Again, please let me gently remind everyone I am a green newbie (but quite teachable).

2. Yes, I have always been checking and filling when the engine is stone cold in the garage after not being used for at least 15 hours. The level has been going down a little after three attempts at filling over a week and around 500 miles driven.

3. What you describe is what I have been doing, and what I have experienced taking the coolant tank cap off. Would you suggest purchasing a new cap if a pressure test does not reveal anything? I am hoping the garage that is checking it tomorrow will perform this test. To me, it seems an essential diagnostic tool.

Many, many thanks for the continued thoughtful responses.

 

The non supercharged cars should not require anything fancy to properly fill them up.

The Jaguar was not filled with DexCool -- The problem GM had with DexCool had nothing to do with the coolant -- it was with owners not understanding taht they had to fill it with DexCool -- and using something else.

You can not use color to find the proper coolant.The colors from different manufactures do not match up . Since Jaguar used different coolant you can use the color as a starting point to determine what is going on - unless you have service records. If you can determine that you have the factory product I would stick with it. if you have added the Dexcool I would switch it all out.

The Zerex G-05 is a good product and if you were to flush out everything -- You should be OK with that. But, that is not to say it is the same product as the Jaguar coolant. All manufactures use base products and then many place additives to enhance the product to meet different needs. Jaguars did not use Ford coolant as supplied in the USA.

It really does depend on what you want out of what is a 12+ year old car -- My car is original -- i know what was done to it so I'm not about to refresh part of the cooling system with a different product.

 

In addition to the usual procedure, some people recommend opening the top of the coolant tower at the front of the engine to release air while filling as it is the highest point in the system.

Upon filling, after reaching operating temperature, the engine should be run at 2000 rpm for a couple of minutes with the heater and fan set at maximum. This is to circulate the coolant through the heat exchangers to drive out bubbles.

You should proceed with caution on the selection of coolant as 1998 is in the period of transition. Jaguar went through three distinct types of coolant during the transition. None of them really like each other, despite claims of compatibility.

You need to determine two things. What was the factory fill for your particular vehicle, and what is in it now. Only then will you know how to proceed.

The whole longlife coolant thing is a mess. No matter what you choose, you cannot go wrong with multiple complete water flushes and then refilling every two to three years.

 

Dexcool can develop problems without mixing with any other coolant. Run a dexcool filled system that has significant amounts of air in the system and sludge will develop all on its own.

 

Just as a matter of interest, I just replaced my thermostat housing, thermostat cover and outlet (collector) pipe, and a couple of heater hoses. I had had a problem with coolant hoses blowing off at the most inopportune times. I got the aluminum thermo housing and cover, but I could not find an aluminum outlet pipe, so I had to go with a new plastic one. After 10 years or so, my pipes had started to warp a little where the clamps are, and I believe the plastic was softening up. The last time a hose blew off, after I put it back on, filled with coolant and got home, I noticed something near the thermo tower hissing. I was fed up with the problem then and decided to go whole-hog and get rid of as much plastic as possible. Final cost was under $200, and about a days' worth of my labor. I went ahead and removed the intake manifold and replaced the manifold seals, the two heater hoses that run under there and the partial load breather pipe - which had been sitting on my shelf for a year. Pain in the butt, but well worth the time and money.