06 Range Rover HSE 4.4L
spent tons of time reading & searching & I cannot figure it out! My only clues are.
No water in oil.
Once it gets to running temperature is when the air enters the system(I think because that's about when the heater starts to lose its heat)
Truck still runs good.

1. Can't find the leak.
2. Tiny bit of water coming out of the exhaust(a drop every once in a while)cooling system is filled with water right now.
3. Once I bleed the system the heater works after running for a bit the heater stops blowing hot.

Here is the link I followed to bleed the system.
https://www.meeknet.co.uk/E38/E38_Bleeding_The_Cooling_System.htm

What did I do first? Being this is my first range rover and I didn't know about the difficulty of getting the air out of the system.

Pulled the water pump, verified it is good.
Installed a new thermostat.
Also the fan comes on at all of the speeds.

Drained all the coolant.
Installed water to the top with the bleed screw unscrewed.
Put the key in the on position. So the aux pump runs. Topped it off again.
Put the car on ramps.
Got the air out by adding water and squeezing the top rad hose to get the coolant flowing.
(Followed the link, did write it in exact detail)

Ran the truck.
Expansion tank stayed full.
Bled as needed
Heater worked great.
Once running temp. Top return line on expansion tank constantly returned bubbles.
After it ran for a bit heater started to blow cooler. And the top radiator hose became very hard(air locked).

I've tried bleeding the system multiple times to eliminate the possibly of it just being air in the system. Same results every time. Heater ends up blowing cool. Shut it off, no more coolant flow with key on the on position.

I've let a small mechanic shop pressure test it to try and find the leak, they said its losing pressure and cannot find the leak. (Rental tools at local parts stores did not have the right cap for me to do it myself)

I've been trying to do a chemical test to see if exhaust fumes are in the cooling system. I have yet to to get it to fail the test. Problem is. To get the air out and the coolant circulating. The expansion tank is filled to the top and I keep getting water in the tester.


I have now just pulled the thermostat out to try and get better coolant flow and that idea failed. Can't get it to start flowing at all with the key on while bleeding.. while running it circulated for bit then almost seemed like it stopped(got air locked but not at the top rad hose. Somewhere else). Right when the heater started blowing cool. Attempted to test for gases and same outcome.

Update: I've ran it for a while without the thermostat, no overheating, but it is pushing water out of the expansion tank cap.



The little bit of water coming out of the exhaust lead me to a head gasket but I cant verify it because I cant get a good chemical test off. Either to high of water or poor water flow.

What's my next step? Bringing it to a dealership / mechanic is not a option. Tried that 1 mechanic shop and they pressure tested it and gave up..




Picture 1. Red circle. What problems can that part cause? How can I test it? Something in my brain leads me to check that.
Blue circle. After running without thermostat pulled that hose and not a drop of water came out.

Picture attached is how much water came out the exhaust from about 10 min of idling.

Have you attached photos because I can’t see anything ?
Is your engine the BMW M62 or the Jaguar engine ?
The meeknet site refers to the BMW.
The coolant flow with just ignition comes from the auxiliary pump on the inner wing which quite often fails but mine has never worked and I bled mine ok with a few problems.

I raised the front of my car and I kept squeezing the large hoses to get air out of the system but if you are getting over pressurised cooling system then that could point to head gasket.

I get quite a lot of condensation out of my exhaust, if you have coolant burning I would expect white smoke but you could check your plugs to see if one is steam cleaned.
If you don’t have exhaust gas in your coolant then it is unlikely to be head gasket but if you are losing water it is going somewhere and if it’s not in the oil then it could just be air being taken up by coolant. Your heater going cold means air is travelling around the system
And needs to come out .
I would try check your plugs.
Raise front of vehicle and fill coolant to near top of expansion tank.
With engine off initially I would squeeze coolant pipes to see if bubble come out and keep doing that with engine running taking care not to lose any fingered on belts or fans. If you are getting bubbles and coolant is dropping then top and keep going replace cap for a bit and unscrew bleed screw to check for air and the remove main cap again and keep squeezing pipes to see if you get more bubbles and coolant dropping. I replace the main cap and loosen bleed screw again to remove more air and excess coolant. Make sure your centre vents are set to hot and heater on full and highest temp. Mine would go cold and I’d drive around the block and it would go hot again. I might have to do this whole procedure a few times until coolant level is correct and stable with good heat inside.
Checkbyou haven’t got any wet carpet from leaking heater.
I’m not sure if any of that is helpful

Here are the spark plugs, oil on them but no signs of being steam cleaned.

At running temperature if I loosen the bleed screw, bubbles come out out the hose from the top of the expansion talve. Almost nonstop. Also after I bled it, ran it for a while(water coming out of the cap) I shut it offer let it cool for a little bit, then opened the cap to burp it. After that every upper hose had nothing in it, (no coolant at all) like they were filled with air, burped the air out, now nothing.. air is getting put in the system I tried bleeding it like 6 times now. It once the upper hoses get air locked it seems like there's no coolant flow from the expansion tank (cant see any flow from the top hose) and that's when I need flow to beable to test it for combustion gases. Also it will be full to the top. Only way to get the air out.

If there is that much ‘air’ getting in then the sniff test would surely react if the gases were exhaust.
If you have antifreeze in it and it was burning it I would expect white smoke but unless it’s getting into the exhaust without going through the cylinder then that’s a bit tricky
You could possibly try UV test to see if exhaust water is coming from

https://www.amazon.co.uk/Torch-Detection-C...B00TU8VCB4

I can’t see any photos on my phone for some reason
Compression and leak down test may reveal something if your cylinders are leaking into coolant but again sniff test should reveal something

Thanks for the replys. When you say sniff test is that the same as the chemical block tester? Tube in the expansion tank cap hole, filled with the special liquid that you suck air into?

Just ran a compression test on all cylinders but the 1 with the stripped coil bolt. Only thing is I did the test with the engine cold. Being I removed all the plugs last night.

Every cylinder is at 175psi

Yes a basic sniff test is using the chemical like the attached which i think you have already done, this isn't a definitive answer as your head gasket or block may only be leaking under pressure or high revs. I think garages have more sophisticated gas analysers. Compression test is good for the 7 you can check.

http://www.superstreetonline.com/how-to/en...iagnostic/

If you are getting water out of the exhaust you could use the dye test as i guess it could be getting into the exhaust valve after the combustion, maybe into the exhaust valve but not being burnt.

If the garage pressurised the system and it is leaking then it is going somewhere where the UV dye might help, if you keep pumping water in under pressure it is going to come out somewhere providing it isn't into the cylinder and then you hydraulic lock the engine ...

A few testers to choose from here

https://www.workshopping.co.uk/category/co...sters/979/

Just ran a compression test on all cylinders but the 1 with the stripped coil bolt. Only thing is I did the test with the engine cold. Being I removed all the plugs last night.

Every cylinder is at 175psi


After that I bled the system for a good 15 min. Started in and continued to bleed it for another 20 min while running.. the temp gauge never moved past half way. But once it got real hot I closed the system up, there was almost constant bubbles coming from the top hose of the expansion tank. And then I eventually turned it off when the engine sounded like it was started to tap because it was running to hot I assume. But the gauge was still in the middle. After I shut it off. You can here the water in the smaller lines ontop of the engine boiling and bubbles were still coming out of the upper hose. Also the hole time I was bleeding it with the engine running, there were bubbles coming out of the upper hose but the coolant level never dropped. Is there a way I can send you videos? Via email?

Are you bleeding it with the heater and blowers on full ?
The temperature gauge only takes the temperature where the sender is, if the water isn't circulating properly it won't read hot. The temp gauge is also stabilised, i don't think you will be able to get the hidden menus up to tell you the true temp.
Do you have touch screen sat nav and is your engine the BMW or Jag?
The hidden menus don't work past 2005 i don't think

Yes I am bleeding it with the heater on, it's a 06 4.4L how do I know if its jag or bmw?

What do you think about putting compressed air striaght into the cylinders, piston top dead center on its compression stroke. If there's a head leak it should make bubbles in the expansion tank.

Regarding the engine you could google M62TUB44 and see if your engine looks like it, I know a bit about the BMW and nothing about the Jag.
What you are suggesting is basically a leak down test but without the gauges. Piston has to be at TDC on the compression stroke so all the valves are closed
Have a read of this
https://mobiloil.com/en/article/car-mainte...kdown-test

The piston may try and move if not on TDC.