[P38] Exhaust gases in coolant

MrGorsky · May 1, 2025

Once it’s warmed up and the thermostat is opened, I rev it with the cap on. If you rev it hard with the cap off you’ll get coolant everywhere. I find it shoves any air out that way. A few blips of the throttle should force coolant through all the pipework. You don’t need to go mad.

kermit_rr · May 1, 2025

Water boils around 100c at sea level.
With a 14psi cap that increases to around 120c. If it's 50/50 antifreeze then it rises further to around 130c. If i recall

kermit_rr · May 1, 2025

The pressure and also the running temp depends greatly on the level being correct in the expansion tank. It will run a few degrees warmer if it's even a bit low

blue_cheese · May 1, 2025

I believe I followed the RAVE method:

- Drained as much as I could via rad plug
- Slowly filled expansion tank with a hose on a small stream
- Started engine, monitored level, waited for thermo to open
- Stopped engine, waited for it to cool, topped up expansion tank again.

I believe that's how it's done it RAVE? Maybe without the garden hose.

Oh and I also blew through the return pipe to clear it

kermit_rr · May 1, 2025

You said the cabin heater return was cold. Can you bypass it in case it is blocked?

blue_cheese · May 1, 2025

Would it be unwise to put the hose directly in to the cabin heater pipe and give it a good blast?

kermit_rr · May 1, 2025

A reverse flush may help? You don't want to kill it though

pwood999 · May 2, 2025

blue_cheese said:
I believe I followed the RAVE method:

- Drained as much as I could via rad plug
- Slowly filled expansion tank with a hose on a small stream
- Started engine, monitored level, waited for thermo to open
- Stopped engine, waited for it to cool, topped up expansion tank again.

I believe that's how it's done it RAVE? Maybe without the garden hose.

Oh and I also blew through the return pipe to clear it

RAVE assumes you drained the system previously. You seem to have missed 12 & 13 in the procedure ? Personally I have an issue with step 17-18. Step-17a should be to top up the system while the thermostat is still open !!

Also during step-15, that's when you also need to keep squeezing hoses to burp the system whilst filling.

Another trick is to use a vacuum pump on the radiator bleed hose whilst filling. That way the coolant tends to fill all the cavities inside the engine better with less airlocks.

blue_cheese · May 2, 2025

I've got 1/2 the vacuum kit, just missing a compressor

I did blow through the hose too. I'll have another go today

kermit_rr · May 2, 2025

Have you checked the small pipes to the throttle body?

blue_cheese · May 2, 2025

Just had another go.

I taped the end of my hoover up and created a makeshift slot for the rad bleed pipe:

And after I filled up to the neck of the bottle, I stuck the hoover on for a few seconds.
The level in the expansion bottle quickly dropped, so I topped it up to the neck again.
Hoover again for a few seconds, and same happened again, so I topped up until water starting coming out of the bleed pipe.

I then did steps 15-19 as normal (including burping).

Currently letting it cool - I'm waiting for one of you to tell me why this isn't going to work and why using the hoover to get the air out is a bad idea

kermit_rr · May 2, 2025

did you use land rover hoover special tool H00V-1?

blue_cheese · May 2, 2025

That was too expensive

Hopefully the coolant doesn't spill out when I hoover the carpet next...

blue_cheese · May 2, 2025

Just been for a 10 minute drive.

Temps idling between 90-91, max 92.

I'll keep an eye on the levels and for any leaks.

Only thing that concerns me - assuming the OBD tool is correct - what kind of damage could have occured if the temps were actually at 118ish?

kermit_rr · May 2, 2025

If you can drive for 15 mins and temp stays at ~92 without top hose getting rigid then you got away with it. I think

blue_cheese · May 2, 2025

Top hose is hard but not rock solid - there is a small amount of give when it gets a good squeeze

kermit_rr · May 2, 2025

That's all relative, shouldn't be difficult to squeeze it.. if it's more like a few mm deflection then it's probably too hard. In my opinion. Maybe

MrGorsky · May 2, 2025

blue_cheese said:
Just been for a 10 minute drive.

Temps idling between 90-91, max 92.
View attachment 340214 View attachment 340213

I'll keep an eye on the levels and for any leaks.

Only thing that concerns me - assuming the OBD tool is correct - what kind of damage could have occured if the temps were actually at 118ish?

May she be sealed forever!

FEI · May 2, 2025

blue_cheese said:
Just been for a 10 minute drive.

Temps idling between 90-91, max 92.
View attachment 340214 View attachment 340213

I'll keep an eye on the levels and for any leaks.

Only thing that concerns me - assuming the OBD tool is correct - what kind of damage could have occured if the temps were actually at 118ish?

Yeah if you didnt put the engine under load and the cap hadnt vented coolant yet i dont think you would have done damage.

If you just idling your cylinder temps wont be very much above coolant temps. But on the other hand if you have 118deg coolant temp but you at 50% engine load your cylinder temps will be extremely high and thats what warps heads.

Datatek · May 2, 2025

kermit_rr said:
That's all relative, shouldn't be difficult to squeeze it.. if it's more like a few mm deflection then it's probably too hard. In my opinion. Maybe

You must have fingers like a robot. With 14psi of hot water in the hose, I can't squeeze far.

[P38] Exhaust gases in coolant

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