I recently replaced the coolant overflow tank and topped off the coolant level. I am experiencing no leaks. When I drive the car for 30 -40 minutes the coolant temperature quickly rises to half on the gauge and stays there. I stop the car and loosen the coolant bottle and there is no pressure built up in the system; also, there is no heat in the cabin. When I try to heat the cabin it seems to just blow recirculated cabin air with no heating.

I will bleed the system again, but is there something I am missing?

 

My usual culprit is the pressure cap on the header tank.

They work hard, and about 7 years is there life.

 

If a new cap doesn't fix it, I'd suggest pressure testing the cooling system. I've had two instances of leaks that were not visible until I connected the pressure tester.

In both cases, the heater didn't put out any heat until system pressure returned to normal. Coolant flow through the heater core seems to be very dependent on system pressure.

 

Thanks guys... I'll do both of the above... as I slept last night fearing a bad head / gasket... I will post as these things are accomplished...

 

You'd have the opposite symptoms for that failure. LOTS of pressure in the system and plenty of heat from the heater.

In both cases for me, with the same symptoms as you, it was just a small coolant leak. No visible leakage until I used a pressure tester.

 

OK.. Thanks; I just drove the car and heated it up. I tried bleeding the system, but no pressure; I then: 1. sealed off header cap. 2. Sealed off bleeder valve with a condom (Safety First). 3. Sustained slight rev (1500 rpm) for a few mins. ... No pressure.. So it seems a pressure test is in order. I also noticed that I have no coolant level sensor on tank, but maybe I was reading about some other model.. and I only spotted one bleeder valve... I was down to my last condom anyway..
I will research pressure testing... any easy DIY tips... or best taken to a shop? I recently purchased this car because I was feeling a severe lack of aggravation in my life... as I was revving; the car began to miss-fire and run rough... after cooling down; the car runs great until heated and worked... more miss-firing... (maybe a condom was not the solution... should have used a case of Pamprin...).

 

Have you seen the ones with jokes printed on them? Some are really funny.

Back to your car. Here's a quick video showing how to do a pressure test:


The tester looks like a glorified bicycle pump. You pump it up to the specified pressure and see if it will hold for a certain period of time. Any leaks will cause the pressure to bleed back down. If the leak is below the coolant level, you will see the liquid. Here's the kicker. If the leak is above the coolant level, these are harder to find because only air escapes, not liquid.

This test is definitely within the realm of anybody with opposable thumbs. No need to take it to a shop. AutoZone and other parts store will loan one for free.

I have a Matco PTK70888 test kit. It looks like a rebranded version of this less expensive tester. Even a knockoff from Harbor Freight should be adequate.

https://www.google.com/search?q=cool...ZdnDd8QgTYI3QQ

Whatever tester you get (or borrow), make sure it fits the Jaguar reservoir neck. Years ago, all caps and radiator necks were pretty much standard, so one tester would suffice for nearly all. Unfortunately now, most vehicles are different, so you'll usually need a vehicle-specific adapter, or some type of universal fit tester.

As far as the rough running, is that new? There's no overheating, right? Just a lack of heat and no observed pressure in the cooling system? Is your check engine light on?

 

Understand that your car has a limiter that prevents you from damaging the engine from revving it up in neutral. 3000 rpm is all you will get if the engine is NOT in gear.

This is normal.
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.
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The check engine light just now came on as the car was heated up and the miss-firing got worse... Seems to be more than one cylinder miss-firing.. I'll code them later.. as for now, I'll try and borrow a pressure test kit from a local store and get one thing solved at a time... (no time today as it is Mother's Day) Happy Mother's Day to all you *****'s...