2011 Sport TDV6 3.0 Head Gasket ?

[Homer the Range]

Is my RRS about to die? HELP !

My 2011 RRS TDV6 3.0 (104k) has been using coolant for the past month. The temperature operates in the normal range all the time even when outside temp is 30+ degrees. I get a low coolant light after a highway run (>100km) and add about 500mls while its still hot to get back to normal fill levels. In response to the coolant loss, I've replaced the expansion tank and cap and water pump in the last month.
Heater core in cabin was making the dreaded waterfall / gurgling sound so I bypassed the heater a week ago and gurgling went away.

When I start the car from cold and open the expansion tank cap - there is immediately a light vapour / mist in the system. I also get vapour / mist when I remove the oil filler cap.

Yesterday I did a combustion leak test and confirmed there are gases are in the cooling system. Today I isolated the EGR coolant hose return and re-tested. I 'hoped' that there might have been a gas exchange happening in one of the heat transfer water jackets.

Unfortunately when I hooked up the combustion leak tester, I could see bubbles in the fluid which quickly turned green, indicating combustion gases - suggesting that they are not coming from the isolated EGR coolant loop.

Video of set up and sound is here: 2011 Range Rover Sport TDV6 3.0 EGR coolant loop isolated - YouTube (https://youtu.be/5xJkUJoVheA)

There is no oil in coolant and oil change 1500km ago showed no signs of coolant in oil and no signs of metal in the oil filter.

The sound from the engine when the oil fill cap is off, is also odd.

Listen here: 2011 Range Rover Sport TDV6 3.0 Diesel engine noise - YouTube (https://youtube.com/shorts/sXkHo9KlnJ4?feature=share)

Are there any other tests that I can do before I throw in the towel on this motor?
I'm gutted - only had this car for a short time and was enjoying the ride.

[shack]

The noise when the oil filler cap is off, certainly sounds odd, but so does our 2.7, so I wouldn't worry.

It's has been making that noise for 300k km.

The other problems would point to other issues though.

There are a couple of well know failure points on the cooling system, one is the coolant manifold in the VEE, the other is the coolant fitting behind the AC compressor.

Neither of these would put combustion gases in the coolant though, but they may have caused the problem.

[Graeme]

Did you close-off both ends of the EGR coolant loop? If only 1 end then exhaust gas would simply go the other way round, not that I've heard of the 2.7/3.0 EGR valves leaking exhaust gas into the coolant circuit.

[Homer the Range]

Did you close-off both ends of the EGR coolant loop? If only 1 end then exhaust gas would simply go the other way round, not that I've heard of the 2.7/3.0 EGR valves leaking exhaust gas into the coolant circuit.

I agree that you wouldn’t think the exhaust gas would have enough pressure to enter the coolant system at the EGR. Would probably expect the opposite. It was a bit of a long shot but I wanted to try. The whole cooling system holds pressure and does not have any visible leaks when parked.

[Homer the Range]

The noise when the oil filler cap is off, certainly sounds odd, but so does our 2.7, so I wouldn't worry.

It's has been making that noise for 300k km.

The other problems would point to other issues though.

There are a couple of well know failure points on the cooling system, one is the coolant manifold in the VEE, the other is the coolant fitting behind the AC compressor.

Neither of these would put combustion gases in the coolant though, but they may have caused the problem.

Thanks shack. I’m happy to hear that the hollow sound may not be that unusual. I’ll check out the vee and the fitting near the ac to see if there are any signs of trouble.

[Homer the Range]

Did you close-off both ends of the EGR coolant loop? If only 1 end then exhaust gas would simply go the other way round, not that I've heard of the 2.7/3.0 EGR valves leaking exhaust gas into the coolant circuit.

Thanks Graeme. I isolated the hose after the two EGRs join at the T and just before it goes to the heater core. I’ll check again to see if I missed a hose …

[PerthDisco]

You’d start seeing some white sweet smelling exhaust smoke if it really started losing through the head gasket.

You could also easily bypass the EGR coolers (join top and bottom hoses) as a seperate quick and definitive test. Take them completely out of the circuit.

My money’s on the EGR coolers.

[Homer the Range]

You’d start seeing some white sweet smelling exhaust smoke if it really started losing through the head gasket.

You could also easily bypass the EGR coolers (join top and bottom hoses) as a seperate quick and definitive test. Take them completely out of the circuit.

My money’s on the EGR coolers.

Thanks PerthDisco. appreciate the input.

I’ll COMPLETELY disconnect the EGR circuit as suggested and report back.

Cheers

[Homer the Range]

EGRs fully bypassed - still got gas entering the system.
Booked in for a specialist to investigate in two weeks and hope we can find the cause…..

[PerthDisco]

Look forward to update.

[Homer the Range]

So it’s been about 6 months since my sport started losing coolant. The problem seemed to ‘correct’ itself after a pressure and leak test was done. I have had no coolant loss for months. Whether that coincides with the end of summer and having the cooling system flushed and new coolant added IDK. Will have to see what happens when it warms up again........thanks to all who provided tips.