Overheating rcz thp 270

[BrunoR]

Hi there,

I am having issues,

Car all of a sudden decides to dump coolant out of coolant reservoir.

Conducted coolant pressure test several times. No drop of pressure or drop of water from anywhere.

Has anyone experienced such an issue? Cause this issue is digging my head in.

Thanks

 

[Flanners]

Is it doing it frequently, is the coolant 'boiling'/bubbling in the resevoir?

Same sort of post at the one you did in June about the same issue, did you replace the thermostat etc?

 

[Pedro]

Maybe one of three things Radiator head pressure/thermostat stuck open or worst case scenario the Head Gasket ? Check for white smoke especially on acceleration The Pressure from a blown head gasket or crack in the head will allow gasses to escape into the coolant system causing backpressure to blow through the expansion tank you won't necessarily see a coolant loss except from the tank as the gas pressure from combustion is sending the pressurised coolant back through system

 

[BrunoR]

Is it doing it frequently, is the coolant 'boiling'/bubbling in the resevoir?

Same sort of post at the one you did in June about the same issue, did you replace the thermostat etc?

no not bubbling....i did not replace thermostat, since we found that the reservoir bottle was cracked and replaced that.

did 3 fun runs since then...and same problem started again

 

[BrunoR]

Maybe one of three things Radiator head pressure/thermostat stuck open or worst case scenario the Head Gasket ? Check for white smoke especially on acceleration The Pressure from a blown head gasket or crack in the head will allow gasses to escape into the coolant system causing backpressure to blow through the expansion tank you won't necessarily see a coolant loss except from the tank as the gas pressure from combustion is sending the pressurised coolant back through system

no white smoke at any point.

The coolant loss is very violent and abrupt and it comes out of the reservoir.

i.e. when I pull over I find the coolant coming out from reservoir.

If I had to do a leak down test would we know if head gasket is ok or not?

Thanks

 

[RCZ-R]

What's the colour of the coolant? Still clean as new? Do you have any pics?

 

[Pedro]

no white smoke at any point.

The coolant loss is very violent and abrupt and it comes out of the reservoir.

i.e. when I pull over I find the coolant coming out from reservoir.

If I had to do a leak down test would we know if head gasket is ok or not?

Thanks

Cylinder head gaskets blowing are not as easy to diagnose as you think they would be I know old mechanics who have scratched their heads when these symptoms show up & they could easily be small faults or something nastier You could try a try both a coolant pressure test which will tell you if the pressure is holding as per the required psi & a compression test will reveal if compressed air is leaking from one or more cylinders & if the gasket has blown water could be leaking into a combustion chamber
The only fix for the Gasket is a new replacement its not recommended to try using leak sealing additives in a HPT Engine

 

[BrunoR]

What's the colour of the coolant? Still clean as new? Do you have any pics?

blue

 

[BrunoR]

Cylinder head gaskets blowing are not as easy to diagnose as you think they would be I know old mechanics who have scratched their heads when these symptoms show up & they could easily be small faults or something nastier You could try a try both a coolant pressure test which will tell you if the pressure is holding as per the required psi & a compression test will reveal if compressed air is leaking from one or more cylinders & if the gasket has blown water could be leaking into a combustion chamber
The only fix for the Gasket is a new replacement its not recommended to try using leak sealing additives in a HPT Engine

coolant pressure test we have performed many times over,

the car has only 30k miles.

I have no issue taking out the head and skimming it and putting in a new head gasket, but I'm more concerned about missing something obvious, one can barely see the engine the way its packed up in there.

 

[Flanners]

I was thinking HGF, sniff test? I have a couple of cars with K series so know about HGF's!

Oil still nice and thin and clear-ish.....or thicker and gloopy when you rub it between your thumbs?

Without the doom in June post you state car got to 120 degrees, for me that would get me worried.

 

[BrunoR]

I was thinking HGF, sniff test? I have a couple of cars with K series so know about HGF's!

Oil still nice and thin and clear-ish.....or thicker and gloopy when you rub it between your thumbs?

what is a HGF sniff test?

Oil clean and level correct.

Thanks

 

[Flanners]

Head Gasket Failure. Sniff Test is a chemical (kit) that can identify exhaust gases in the coolant. Not 100% but an indication.

Have you connected a reader to see if there are any codes stored?

 

[Pedro]

HGF= Head Gasket Failure test but as stated before all tests need to be done to make sure its not a complete coolant issue You may have a knackered water pump without any soundings which may also cause this pressure build up as for a "Sniff test" it may point to the Head gasket but its a process of elimination
Check the Rad hoses to see if they are not oversized ( Bulging slightly or oval shaped)
What Temp is the Engine running at when Hot? ( is it normal)
When the Coolant is cold is their any oily residues floating on top in the expansion tank even small swirls of white coloured residues is a issue to look at as Flanners pointed out ?
Lastly if as your previous post last June stated the Temp reached 120 degrees you may have over time split open the Gasket

 

[BrunoR]

in fact we have decided to change all, thermostat and housing, head gasket the whole works.

what we noticed is that when the car is at normal operating temperature i.e 90 deg, after a good run even before it overheats, one starts to see coolant seeping out of the coolant bottle tap. The coolant starts to boil and looks like you are seeing a kettle boiling water. The level in the reservoir also rises.

After it cools down the reservoir water level goes back to normal.

 

[Flanners]

My MG TF had the same symtoms the coolant was boiling over at operating temps, it was also leaking form the block/gasket (difficult to see where from). Took the Head off and could see that Exhaust gases were leaking into the coolant. That's why I asked if the coolant was boiling in the resevoir as obviously it should not do that.

This is the second Head Gasket failure I have heard about on the RCZ. Hope you get it sorted

 

[BrunoR]

My MG TF had the same symtoms the coolant was boiling over at operating temps, it was also leaking form the block/gasket (difficult to see where from). Took the Head off and could see that Exhaust gases were leaking into the coolant. That's why I asked if the coolant was boiling in the resevoir as obviously it should not do that.

This is the second Head Gasket failure I have heard about on the RCZ. Hope you get it sorted

yes pity really car has basically no real mileage

 

[Pedro]

in fact we have decided to change all, thermostat and housing, head gasket the whole works.

what we noticed is that when the car is at normal operating temperature i.e 90 deg, after a good run even before it overheats, one starts to see coolant seeping out of the coolant bottle tap. The coolant starts to boil and looks like you are seeing a kettle boiling water. The level in the reservoir also rises.

After it cools down the reservoir water level goes back to normal.

Yea its the classic gasses escaping through the cooling system that's why Engines need a good mixture of Anti Freeze its the only thing that will save the heads from warping & cracking & not blowing out the rings on the gaskets

 

[RCZ-R]

Is the water pump operating correctly?
That thing in the R engine is not only driven by an external force but has also valves inside operated electrically by the ECU.

 

[Grimreaper]

Sounds as if your not clearing an air lock in system fully

 

[Iulia]

Hi I know the post is old, but I have the same problem with the liquid boiling in the expansion tank, how did you manage to solve the problem?