So I recently aquired a 2000 S-type with a 4.0L that is in REALLY nice condition and has 70k miles. The only thing it DOESN'T have going for it is it is burning coolant/overheating. Quite a bit of it. The car still runs good just smoking. Head gaskets?

 

Is that smoke from the tailpipe or the engine bay ?

 

Welcome to the forum.

Congratulations on your purchase. Do yourself a YUGE favor and figure out the root cause of the problem versus throwing parts at it.

What are the exact symptoms of overheating? You mentioned visible clouds of coolant. From the tailpipe or under the hood? Any abnormal noises? What is the temperature gauge showing? Maybe the problem is as simple as an external leak.

Please be aware the temperature gauge is deliberately misleading. From approximately 180-230F, the needle is centered. I'd strongly suggest connecting a scanner and reading live data for the coolant temperature, to keep an eye on things for now.

Next, I'd beg, borrow, or steal a cooling system pressure tester. It looks like a bicycle pump with a gauge. It connects to the neck of the coolant reservoir, in place of the cap. Engine off, manually pump up the system to the rated pressure on the cap. The pressure should hold for at least 15 minutes. Any external leaks should be visible now with the system pressurised. If you tried looking for leaks at idle, most medium or smaller leaks won't be apparent, as there is very little pressure in the system. The manual tester builds up enough pressure to make leaks easier to find, and you can poke around with no danger of moving parts.

Test the cap, too, to make sure it is not venting early. Most test sets include an adapter for the cap.

Next step is a special tester that looks for exhaust in the cooling system. It looks like a turkey baster and has a little compartment holding special test fluid. With the engine warm, you draw a sample of air from the top of the coolant reservoir. If exhaust is present, the fluid changes color.

Some auto parts stores have free loaner tools. It won't cost you anything to borrow both testers.

 

Yes it is burning it and coming out of the tail pipes/smoking. Seems to be more out the drivers side but it does come out of both sides. Car does not make any abnormal noises or anything like that. Just consuming the coolant. I have a pressure tester just havent got to do that as of yet. It has been pouring here since I got the car.

 

Welcome. What Karl said...

Where is "here"? When you find a moment, you might want to go to the New Members Forum and post the usual (and expected) "introduction"; the forum can be found here:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Steps:
1. with a mirror and some twisting around your car and find the LEAK. I bet you it has one. The expansion tanks all crack on these and they leak out under cowl and drip out on the floor or go to the frame and hit the exhaust pipes.
2. hoses. carefully check ALL of them with engine at op temp.
3. The plastic thermostat housing. Same with temperature.
4. Radiator
5. The heater tubes and the inside heater coil.
It is somewhere in all that. FIRST guess....fill the system, bleed it, and bring it up to temp. then get it parked and start at the expansion tank. If you see liquid on the ground behind the driver side front wheel, you got it. Mirror, bright light, rubber gloves. Good luck. BTW, I have done this job.

 

If it is coming out of the engine, the oil is usually very chocolate milk color.

 

I am not betting, but my 2000 '04 S had this sort of leak. IT WAS TWO adjacent cylinder getting this fluid. FWIW, my 2001 5.4 F150.( also a Ford,) had the same leak. The F150 HELD 17 PSI under testing
EDIT; The oil was fine.

Repairing the S now, trying to decide what else to do while it's open.

 

Seems very likely. Mine has that issue. Opening it showed 2 cyl of the 4.0 being leaked into. I read a lot on these and this leak.