Gurgling after turn off

[mlewi6]

Hello:

I am puzzling with the latest problem. My engine cooling system is all working fine. Runs cool, fans turn on as they should, after shutdown the recirc pump works etc. But, after shut down there is a gurgling/boiling sound coming from the thermostat area with the occasional violent blow back through the hose from the thermostat to the header tank. I have replaced the rad cap twice, with the latest one from SJ, I have drained the coolant and run the engine with the cap off to "burp" the system, and I do not believe there are any leaks in the system. My research leads to confusing prognosis ranging from this is usual to a blown head gasket. Anyone any ideas? As always, thanks for all of your amazing knowledge and help.

Martyn Lewis.

[Simon_P]

Is your recirculation pump pumping in the correct direction?

[lotusflasherman]

Sounds like an airlock in the thermostat area to me... You have got the proper thermostat with a giggle pin positioned at 12 o' clock haven't you?

[tigerdog]

interesting - Smaug does the same thing and I don't remember when it started. It's clearly related to heat sink from the turbo after shutdown. I'm interested to hear the resolution.

[mlewi6]

Thanks for the responses - the thermostat, as far as I know is as it came from the factory. I'll check the recirc. pump direction, but it isn't usually on as soon as you turn off. It comes on after a couple of minutes and the boiling sound then diminishes (doesn't go away) and then gets more violent when the pump turns off. I will check those hoses though.

Martyn.

[Simon_P]

Ah it sounded like it did it when the pump was on in the first post.

Check the header tank cap, if it doesn't hold the right pressure the coolant will boil.

Also bleed the system to make sure there is no trapped air.

[markcraig]

New M100 owner and my car is also exhibiting this behavior.
Has anyone found a specific cause or remedy?
The car is not running hot and the fans and pump work normally.
Thanks for any advice.

[peteoddcar]

Try running for about 30 seconds at idle before switch off.
Sounds like coolant boiling in the turbo.

[lotusflasherman]

Try running for about 30 seconds at idle before switch off.
Sounds like coolant boiling in the turbo.

only 30 seconds Pete ! Owners Handbook Page 24 "Stopping Engine" says idle engine 2 to 3 minutes to stop oil burning (carbonising) in turbo. Wonder how many owners actually do it...

[John_W]

But the addendum says that if you live in Aberdeen you don’t have to, because you’re lucky if the temperature ever gets up to “warm” anyway.

[simonbuk]

only 30 seconds Pete ! Owners Handbook Page 24 "Stopping Engine" says idle engine 2 to 3 minutes to stop oil burning (carbonising) in turbo. Wonder how many owners actually do it...

Never knew that !!

[JusNoGood]

I think its pretty typical for all turbo cars. The Official guidance I received for my Subaru and BMW was to stay off boost for the last 5 mins of a journey or idle for a few mins.

[sideways]

Try running for about 30 seconds at idle before switch off.
Sounds like coolant boiling in the turbo.

only 30 seconds Pete ! Owners Handbook Page 24 "Stopping Engine" says idle engine 2 to 3 minutes to stop oil burning (carbonising) in turbo. Wonder how many owners actually do it...

"After fast driving idle engine etc..."

I generally do my cool for a few minutes on the way home - but I don't drive fast any more.

[JusNoGood]

Try running for about 30 seconds at idle before switch off.
Sounds like coolant boiling in the turbo.

only 30 seconds Pete ! Owners Handbook Page 24 "Stopping Engine" says idle engine 2 to 3 minutes to stop oil burning (carbonising) in turbo. Wonder how many owners actually do it...

"After fast driving idle engine etc..."

I generally do my cool for a few minutes on the way home - but I don't drive fast any more.

yea, looks well cool in your avatar

Sorry couldn't resist.

[sideways]

yea, looks well cool in your avatar

Sorry couldn't resist. [/quote]

That's why I don't go fast any more! I went from 90mph to zero to flames to remains in less than 20 minutes.

[JusNoGood]

yea, looks well cool in your avatar

Sorry couldn't resist.

That's why I don't go fast any more! I went from 90mph to zero to flames to remains in less than 20 minutes. [/quote]