I have a 2004 Jaguar S type with with the 4.2 l motor. I can fill up the coolant reservoir to the correct level and then drive the car about 20 miles and the engine overheat engine warning light comes on. I can smell and antifreeze at times however it isn't leaking and my ODBII ,connector using the Torque app tells me the engine is running at ~194*. I replaced the coolant reservoir and the cap as I saw some antifreeze on the edges of the old one and thought that could be the problem? It was not. I don't see any antifreeze coming from the water pump then when I park the car I can come back and look underneath and there is a small amount of antifreeze that appears to be leaking from the front of drivers side towards the front spoiler area. Does anyone know what this might be? The highest reading I have ever seen on the Torque app is 201*. Also it doesn't leak or overheat at idle. It seems to only happen while under load?

 

Do the radiator cooling fans cut in all the time when the overheat lights are on?

Did the new reservoir come with a new level warning switch or did you re-use the old one?

Did you correctly bleed the water system when you changed the reservoir?

Did you use the correct long-life anti-freeze? (It can cause issues if you mix this with normal anti-freeze.)

I think there was an issue with the 4.0 engines having the blades on the impeller inside water pump disintegrate, but I do not think this is a problem with the 4.2l cars.

If you rule out the obvious I recomend you use the Jaguar SDD software to help you find the issue.

Mellow

 

Thank you for the super quick reply mellow! I haven't done a few of the things you suggested however I will and will post a follow up once I have tried them. I didn't bleed the coolant system when I changed out the reservoir and that could be at least part of the problem. I also haven't checked the water pump as I've not got that deep into it. I bought the Jag from the original 80 y/o lady that had it and it only has 91k miles. I also have a Porsche that is my daily driver. Once I have some time to dig in I will go through all your suggestions.

Much appreciated!!
Kane

 

Just beside the coolant cap there is a small (plastic) bleed screw. Remove it and slowly fill.

Also, these S-types have under car panels. So the exact location of the leak is not necessarily where drip falls to the ground.

Typical coolant leak sources are: radiator, DCCV, pipe under intake manifold.

 

wydopnthrtl,

Thank you for the reply as well. Since you mentioned the under panel that reminded me that it seems to be dripping at the very front (drivers side) of the second under panel back. I will need to take that panel off most likely to find the source.

I appreciate everyone's fast replies! :-)

 

I say second under panel when I should have said the one that connects to the front spoiler.

 

Here are a couple pictures. We did just get rain here so I am not sure all of what is seen on the ground is antifreeze but some of it is and there wasn't any antifreeze when I parked the car yesterday. This seems to happen once the car is parked for some strange reason?

 

Mellow,

To answer your questions...

Do the radiator cooling fans cut in all the time when the overheat lights are on?
Not all the time however I do hear it on occasion.

Did the new reservoir come with a new level warning switch or did you re-use the old one?
I reused the old one. I wasn't aware this was something I should have replaced?

Did you correctly bleed the water system when you changed the reservoir?
I did. I took the small screw cap off and slowly added antifreeze.

Did you use the correct long-life anti-freeze? (It can cause issues if you mix this with normal anti-freeze.)
I use the orange antifreeze as that is what the sticker says to use.

 

Definitely remove the big panel underneath and the smaller one directly under the radiator...fill the cooling system as best you can without starting the engine...the colder the better for safety....especially if you are on jackstands....use a pump up style pressure tester and start looking....good luck

 

scottjh9,

Sounds like the correct path. I want to thank everyone for the quick replies. I will post a follow up in a few days. May be the end of next week before I can get to it but I will reply for the sake of others that might have the same problem.

 

Well, actually, your car does have a leak. You just haven't found exactly where, that's all.

To pile on the other comments, use a pressure tester and look for a leak that way. This is far more comprehensive that just doing a visual look-see with the engine at idle. Under those conditions, not much pressure builds up and smaller leaks may not be present. Use a pressure tester and pump up the system to the rated capacity on the cap. Make sure the cooling system can hold pressure for at least 15 minutes or so. Pressure test the cap, too.

These vehicles are very sensitive to cooling system pressure. If a leak is present, the pressure never builds up to the required level. Some leaks, especially high on the engine, will mostly vent air and not much liquid, so leakage is not always obvious. Coolant flow through the various passages is affected when pressure is low, even if the quantity is okay. Overheating, false indication, and erratic heater operation can result. So get thee a pressure tester and make sure the system is liquid tight.

 

Glad to help....if you are going to drive the car more, then i would suggest putting some coolant dye in the system the next time you top off....it really helps

 

Again I would like to thank everyone who has replied to my post. I do not drive this car daily and and not at all until it's properly fixed. I have been driving my Porsche.

I will reply back once I had found the problem and/or I need more help to let everyone know the latest update once a have some time to fix the car. It has basically been setting for a year and I note this is not good for any car.

Thanks again everyone!!

 

And it is quite obvious that "talk to text" isn't working well today! lol

 

From jaguar to porsche.....bet you can't wait until the jaguar is top shape to make that daily decision...good luck with your repairs

 

@Kane Emery, as Karl suggested in post 11 above, use a pressure tester after a cold soak, preferably overnight, to determine the source of the leak. Pump the pressure tester to 1 bar and see if it drops after ten minutes. If it does, find the source of the leak and correct it.

If the water outlet has not been replaced, it should be replaced as an assembly as it can only endure a finite number of cold to hot to cold cycles before failing. The hose from behind the water pump under the inlet manifold to the throttle body is also prone to failure and should be replaced or it can leave you stranded.

 

All,

Thanks to everyone for their help. I wanted to let everyone know that after pressure testing we found that the problem was the bleed screw on the reservoir. It was barely leaking after running the pressure up to 25 psi. I noticed that there were water marks on the underside of the hood that I had missed that would have been a tail take sign of the leak.

End result was a 10 cent o-ring.

Thanks to everyone for the help!!