Coolant boiling on engine shutdown

[Kiwi downunder]

Hi,
I had my PB challenger serviced some months back and have to top up the coolant a couple of times when I had an overheat due to re-use of old hose clamps and a couple of different leaks found.

Problem:
When I turn the engine off the coolant starts to gurgle and boil into the overflow bottle..... I have never noticed this before/ is this normal. This has been happening for a couple of weeks plus now.

I used what was probably a different coolant to top it up, The coolant still looks good without apparent thickening (at the cap), Driving temperatures when warm are at 96 degrees. (If I can trust 'Torque Pro' preset PID)

Any ideas/ recommendations..
I have tried to look at how to flush the system/ coolant change but I cannot find where you drain the block.

Thank you in advance.

[old Jack]

According to the Service Manual there is no engine block drain plug on the 4D56 engine.

From the Service Manual;
4.Drain the engine coolant in the water jacket by disconnect the engine oil cooler water feed hose of the engine oil cooler <4D5>

http://faq.out-club.ru/download/pajero_sport_2008/maintenance/Service_Manual_2009_2011/img/14/AC503674AF00ENG.pdf

OJ.

[Kiwi downunder]

Cheers OJ,
I have looked at this and I cannot figure out where this is exactly... not much room with the air hose oil filter in the way. Has anyone taken pictures. Hard I know, as little to no room.
I've tried to look for video on line as well.

[Keithyv]

96 is about 10 - 15 degrees too hot IMHO.
Something not right there.

[4ePikanini]

Are you taking it easy the last kilometer or two before stopping at home?

Working the car hard and then quickly shutting down will cause bubbling.

Do you have the correct ration water to antifreeze?

Radiator fins clean?

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[Kingbrown]

Oil cooler (ribbed cylindrical thing) sits behind the alternator and the coolant hose is in the gap between them (and lower down).

If you go to the driver's side wheel arch and remove the rubber flap then the hose will be virtually in front of you (but lower down).

[old Jack]

Coolant temperature should be close to ambient temperature after the engine has been off for 8 to 10 hours and sitting overnight. Is Torque Pro calibrated correctly?

OJ.

[Jasonmc73]

Mmmm,

Sounds bit like exhaust gas pressure releasing into your overflow bottle.

Head gasket & or head issue??

There are test kits you can use to check. We use them at work.

Something like this, cannot recall the exact brand we use

http://liquidintelligence.com.au/products/blown-head-gasket-test-kits

[Kiwi downunder]

Coolant temperature should be close to ambient temperature after the engine has been off for 8 to 10 hours and sitting overnight. Is Torque Pro calibrated correctly?

OJ.

Yes, ATF & coolant temperatures are at/ near ambient when cold about 3 degrees difference.

[Keithyv]

Challenger has an issue right with this very problem?
Is your car one of the affected ones or has it already been addressed?

[Kiwi downunder]

Oil cooler (ribbed cylindrical thing) sits behind the alternator and the coolant hose is in the gap between them (and lower down).

If you go to the driver's side wheel arch and remove the rubber flap then the hose will be virtually in front of you (but lower down).

Awesome, thank you, that's where I though but couldn't figure it out, this helped a lot.

[Kiwi downunder]

Are you taking it easy the last kilometer or two before stopping at home?

Working the car hard and then quickly shutting down will cause bubbling.

Do you have the correct ration water to antifreeze?

Radiator fins clean?

Sent from my S55 using Tapatalk

Yes radiator fins are clean, and yes its a hard push uphill to home and I shut it down fast (been doing it for years), I have discovered It is alleviated by me restarting and letting it idle a while,
I have had to top up the coolant because of a poor service and hose clips not replaced/ loose.... I have since read that this is a big no no to mix coolant.... so its a coolant change/ flush coming up for me next stop.

[4ePikanini]

Yes radiator fins are clean, and yes its a hard push uphill to home and I shut it down fast, I have discovered It is alleviated by me restarting and letting it idle a while,

I have had to top up the coolant because of a poor service and hose clips not replaced/ loose.... I have since read that this is a big no no to mix coolant.... so its a coolant change/ flush coming up for me next stop.

Let it idle a bit before shutdown. You are saving the turbo as well by idling.

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[Kiwi downunder]

Challenger has an issue right with this very problem?
Is your car one of the affected ones or has it already been addressed?

If you mean they changed the coolant ratio and put a higher pressure cap on to fix a design flaw, then yes it has been addressed some years back (If you call that a fix), but I have since changed service agent (bad bad move) so coolant ratio could be wrong, I need to change it ASAP anyway, (as I have mixed coolants when I topped it up)

[KevL]

Coolant boiling on engine shutdown

This sounds very much like the cooling system/block surface finish problem that thousands of these engine had. Off to Mitsubishi.

If you put green coolant in with green coolant you’re fine. The gelling problem occurs when ethylene glycol coolant( green) is mixed with some GM coolants (orange)
Some other types shouldn’t be mixed, but they don’t gel. The best bet is don’t mix colours.

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