Had been noticing coolant resovoir level dropping below min now and again, today thought was unusual it went up... Had pressure test on hoses and radiotor, slight leak from what we thought was a valve... Replaced and level still dropping way below minimum now and again, coolant level warning light on and overheated.. Only overheated once, stopped right away and topped up, steam everywhere.. Had head recon done few months ago, so now checking that was pressure tested... Pressure testing whole coolant system again...

Edited 26 August, 20206 yr by j.hilmar.christens

Leak from the radiator thermoswitch seems to be rather common, but can be resolved by just nipping up the existing switch a bit tighter, rather than replacing anything.

 

Try this; After an overnight sit, where the car was used the previous day, undo the expansion tank cap before starting the engine.  Listen for any hiss of escaping pressure as the o-ring  clears the neck.

Pete, thanks again for quick reply. The switch was changed as we thought that's where leak was... Thanks too for advice reg resovoir cap... 

On 26/08/2020 at 20:03, j.hilmar.christens said:

Had been noticing coolant resovoir level dropping below min now and again, today thought was unusual it went up... Had pressure test on hoses and radiotor, slight leak from what we thought was a valve... Replaced and level still dropping way below minimum now and again, coolant level warning light on and overheated.. Only overheated once, stopped right away and topped up, steam everywhere.. Had head recon done few months ago, so now checking that was pressure tested... Pressure testing whole coolant system again...

So all gone to pot, had car recovered yesterday, heard clicking noise from engine and think gasget gone, this looks like might have been from head recon rebuild, could it be was not bolted on properly? Was told could be crack in engine or head? Mechanic looking at it today, I'm fed up with this and waking up thru night thinking about it... Video attached... Can't attach that but from this area... Pic attached... 

 

Edited 30 August, 20206 yr by j.hilmar.christens

17 hours ago, j.hilmar.christens said:

So all gone to pot, had car recovered yesterday, heard clicking noise from engine and think gasget gone, this looks like might have been from head recon rebuild, could it be was not bolted on properly? Was told could be crack in engine or head? Mechanic looking at it today, I'm fed up with this and waking up thru night thinking about it... Video attached... Can't attach that but from this area... Pic attached... 

 

We discovered one of bolts securing head was not torqued onto engine head (was seized when head was broken down so thread was damaged when unbolted)....the pressure test confirmed as leaked thru bolt...we could have put in thread insert but mechanic said we could not? Pic attached...leaks from other areas too... 

Is that photo from a new disassembly of the head? If so, that head bolt looks like it has been re-used, and not even cleaned up prior to refitting.

Thats the old bolt that was seized, new bolt was used when recon was done.. Im just wondering and assume that bit sticking out is the locator for head and if a thread insert could have been used, I was told it couldn't due to its location... The new bolt did torque but  ow failed, rebuild was done back in May.. 

On 26/08/2020 at 20:03, j.hilmar.christens said:

Had been noticing coolant resovoir level dropping below min now and again, today thought was unusual it went up... Had pressure test on hoses and radiotor, slight leak from what we thought was a valve... Replaced and level still dropping way below minimum now and again, coolant level warning light on and overheated.. Only overheated once, stopped right away and topped up, steam everywhere.. Had head recon done few months ago, so now checking that was pressure tested... Pressure testing whole coolant system again...

So here's the end to the story, the bolt on head was not torqued or it was, thread insert could have been put in when was told it could not due to dowel... Will add pic below... So leaks from bolt and think gasget... Think said had coolant leak before recon was done... Enough was enough, sold for 400 to We Buy Any Car... 2006 Polo was great runner but when bought was told should not have... 1.2 litre and changed timing chain too... Money pit.... Done 105k miles... Make sure change your oil more frequently I was told for timing chains...