hey guys i dont know here to start but today my XJR usually runs between 195-203 temperature, this car only stays local never on long distance drives, during one of my local trips i have a digital engine coolant temp gauge. it was reading 215-222. i thought wow that is pretty high for a 75F day. highest i have ever encountered.


The fans would stay on for a minute or so after i shut the car off. the first few trips of the day. during that time i kept my eye on the gauge at one point it hit 225 degrees. i turned on the heater to cool it down it went down to 215. that is when i knew something was wrong. so i checked the coolant tank it had coolant in it. but it had slight leak around it. so i opened the tank to check if there was coolant inside; there was.


i was at my sisters house during that time about 8-10 mile drive. i got a low engine coolant light. once i reached home i opened the coolant tank; it was empty! i panicked thinking i ran the car dry. so i added the fluid back into the reservoir it took a whole gallon of orange coolant. so that cant be right.


i am loosing coolant somewhere but no puddles under the car. so i have no idea where to start. i am wondering if there is a way i can check wither my water pump is working. checked the fuses they are good. no black/blue/white smoke from the tailpipes. car starts up fine and runs. but i turn it off before it reaches 225F degrees.


so far i have added coolant waiting for the car to cool alot before starting it again and checking the coolant level again. and update this again.


any advice would be appricated. thank you!


To Long Didnt Read: car temp was running high, checked coolant level was okay, continued home, got a low engine coolant light, coolant reservoir empty, added coolant. temp reached 225F degrees.

 

There's air trapped in the coolant passages. Let the car cool, add more. Fix the leak ASAP..

 

Ok, possible areas to leak....
1. there are 2 lines that go under the S/C and if you've never done them, its highly recommended and a possible source of your issue.
2. water pump, the weep hole is on the top and is rather easy to get to once you take off the belts.
3. check your oil for water, it will be a milky residue in the oil....issue, head gasket.
4. reservoir tank from overheating, it turns to steam and evaps there.
5. head gasket, where fluid is compressed and turns to steam and exits the exhaust unnoticeable. It will also cause overheating. I'd check the plugs for color...anything but a tan white ash is questionable. Also do a compressions check.

 

appreciate it thank you; i was able to add more coolant in the coolant tank; but for some reason the supercharger coolant pipes feel empty; could a leak be internal inside the supercharger? just wondering the tank stays full but once i start the car the coolant starts to overflow...does that mean the pump is working?...i install the cap and let the car idle it...it stays at 203 a little while longer before it starts rising again...i turn the car off at 225F again. ill keep adding until i figure out where the leak is coming from.


for some reason i feel that; the small coolant lines that lead from/to the coolant tank might be clogged? is there anyway to detach the those hoses and check them?


i will try all those suggestions. i might have to take it to mechanic on monday.

 

The small lines bleed air from the system. They "unclip" and have an "O" ring. Some cars have the tool needed already attached to the mid connection of the supercharger radiator line - otherwise you can use two small nails to expand each side of the clip and separate the connection. Care must be taken as to not damage the lines -- with age they become brittle.

Honestly -- I don't think they are clogged ... even if the wrong coolant was mixed and it gelled a bit.

The fact that you don't see any coolant is a worry. It can't disappear. I think you should take the car and have the cooling system pressure tested. It's not expensive and will tell you what is up. If one of the head gaskets failed -- best to know. If it is something else you don't want to overheat the engine.

The 01 should have the later pump --maybe not the latest .... but a bad pump would not explain the missing coolant. The fender overflow will hold coolant -- but ......it sounds like you are now over two gallons expelled.

 

Has anybody else been working on the car: oil change, etc? Frequently, folks will put those pipes from the reservoir on backwards: the pipe to the radiator is outboard (closest to the fender); the pipe to the overflow bottle under the fender is in-board.

Still sounds like a bad water pump and/or Thermostat.

 

thank you... i am going to have the cars coolant system tested and i will report my findings. i did notice that under the driver side front bumper it was wet.(i will double check that now too) hoping its a hose leak and not a head gasket. yeah 2ish gallons is a ton. i reached high temps 225-230 would that warp the engine?

 

thank you for responding. nope no one was working on the car for at least two months last thing done to it was oil change and transmission flush.
would you consider 230F temps overheating? i am afraid that high temps might have warped the heads. i am going to have the cooling system pressure tested and head gasket tested. i will report back once i get my findings.


just checked under the car right now. no leaks underneath but the coolant tank has wetness arond all the connections. underneath the bumper driver (US) side the overflow tank has coolant in it. tank is at the same level as yesterday. i noticed that when i open the cap. i hear a single "gulp" is that from the over flow tank?

 

I also like Jhartz basic analogy of the thermostat. Its cheap and easy to change and could be building pressure if its not releasing.

 

Check those black hoses from the reservoir. It sounds like the overflow tank under left fender has your coolant: THE HOSES ARE NOT CONNECTED CORRECTLY!

220 is too hot.

 

The car does have an overflow in the drivers fender ... it operates as an overflow vs an expansion tank. I'm not sure how much it will hold -- 2 gallons is a lot. Testing the thermostat is an easy job -- can't hurt anything. Look it over and place it in some hot water.

There are some reports that fluid will flow back from the fender tank -- but that's not the primary design or reason for the tank. I don't remember how much it will hold.

It's primary purpose was to eliminate any chance of coolant dripping. FYI: Until Ford came into the picture (1989) Jaguar was always short of cash. They understood things needed to be changed but never had the money. Jaguars -- leaked and groaned and overheated. Ford wanted to eliminate leaks -- even from the possible overflow. They specified special ) for the early 90's) low ambient power steering fluid ... they even manipulated the temp gauge.

 

Actually fluid does flow back from the overflow tank. As the engine heats up coolant expands and passes through the pressure tank cap to the overflow tank, then returns as the engine cools.

This is just like the radiator overflow on a more conventional cooling system.

 

If your thermostat is not working many things can go wrong. I would start car and let it idle until temperature reaches 85c and simply touch hoses to see if thermostat opens up.

You may also have a crack somewhere in the hoses or connections that opens up under pressure and steam/coolant is escaping when you ride. Same thing - while car idle just observe what happens when it becomes hot.

In theory you may have leak in some gasket, but in that case you would find coolant in your oil (your oil level is fine I guess), or in your exhaust(rough idle, smoke/smell out of exhaust), but it's rare.

How fast are you losing coolant? I had a leak like this in thermostat housing and low coolant light would come up every 2-3 weeks. Turned out I had a crack in the cap and when pressure was high - it would leak and evaporate on the spot.

More things to check - the cap on the expansion tank has a valve inside, that valve controls max pressure in the system. Sometime that thing get's stuck and pressure in the system goes too high for hoses and clamps so they leak.

 

i have never lost coolant prior to this incident.

slight update: first of all i like to say thank you all of you for stepping up and helping me out... so far the car has been sitting in my garage. i am taking it to a friends shop tomorrow morning. i will update you with the results.

i have been doing research about what possibly went wrong.

(at my sisters house, drive way) fans were on while car was off. i remember touching the top radiator hose and it was hot; while touching the lower hose and it was semi-cool almost warm but not quiet. i have been under my car before this incident and i remember the tank below the bumper having very slight fluid in it.

i recall at my sisters house looking at the coolant tank (top one) and it was full. during my drive home about 5 minutes into it i got the "low engine coolant light" kept a very careful eye on the temperature and it was reaching 225-228F. got home safely.

opened the coolant tanks cap it released pressure but it was empty inside. during that time i added more coolant to fill the top tank. about four times in total. like an idiot i kept adding more coolant starting the car. and repeating.

then i checked under the car for leaks. had spilled some but i could tell what area i spilled at. also noticed that my tire was wet and the suspension on the driver side... i did not notice the tank below the bumper at the time.

came on the forums in a panic assuming it was completely out of coolant and i drove it. during that time i checked under the car again. thats when i noticed that the tank below the bumper was nearly full.

so my question is im pretty sure my thermostat was stuck closed. and all the coolant expansion plus the coolant i added just fell into the tank below the bumper. do you think the car ran dry because the thermostat was closed? i failed to check the hoses at that time to feel if they were empty or had fluid in them.

my worry is the high temperatures might cause a head gasket failure. i started the car for about 10 seconds each time when i was adding coolant. and the temps during that time were in the 198-225s. i will update tomorrow once i am back from testing.

 

When adding coolant to COLD car I would add it through thermostat housing, just unscrew that cap (I would also put cap back and squeeze hoses few times to move coolant around a little to get air out, then fill more ). Once full there - some more to the expansion tank.

If you are sure the thermostat is stuck - it is an easy fix.

 

okay got back from the mech shop: he did a coolant pressure test and it failed and he pointed to me where the leak was...its below the supercharger. he said he checked the gaskets (didnt do a compression test like i asked him to; but checked it for free). i dropped it off i was not there when he did the test. he was saying that they are good.

so now drove the car back home about a 1 mile trip. and i got a CEL it is P0327. whats P0327. hopefully nothing gasket related... i did drive the car cold at 70F-90F on my way home because i did not want it to over heat. so i cranked it and instantly started driving home. could that have tripped the CEL?

my questions:
P0327 is that gasket related?
i am going to remove the supercharger to point where the leak is coming from. if its a hose i will fix...if its from an engine block then time to cut my loss and let it go.
is there a "how to" on removing the supercharger?
what gaskets/tools/etc will i need?

 

P0327 could be water on your knock sensors.

 

thank you king! im glad its not head gasket related. but that must be it, its been raining a lot today and its been parked outside at his yard. i never taken it out in the rain before.

can anyone give tips on the supercharger removal? or even a how to? i kinda have been looking into it. found a few pdfs. these are the steps i planned out.

My plan:
1)remove hood, easier access to everything
2)remove belt
3)drain coolant...hopefully theres a radiator drain plug on one side.
4)remove intake box up to throttle body.
5)remove thermostat mount

up to that point i can do it from then on ill need your guys help!

what gaskets will i need? i was able to find the main supercharger gasket. is that the only one or is there more. maybe intake port gaskets? if there are any. no experience in doing this before.

thank you

 

Yes with leaks & coolant system tests/work being done it's a likely scenario.

 

Supercharger is super easy to remove, its the dang throttle body that gets in the way. The bottom 2 bolts are a bear, especially the one on the driver side.
Follow the link in Post #4, https://www.jaguarforums.com/forum/x...leaking-84282/, there are two hoses under there and I recommend you and also do the elbow one from the back of the bypass. I got my hoses for a real good price from Welsh Enterprises in OH, ask for John in parts he's a great guy. Welsh Enterprises - New Jaguar Parts, Used Jaguar Parts and Accessories - XK120 - XK140 - XK150 - E-Type - MK - XJ6 - XJ8 - XJ - XK8 - XK - XJS - S-Type - X-Type - XF