Problem with coolant & pressure

[pinstripe]

Hi all

 

i have been dealing with this problem for some time now...

 

i have problem or i at least think so with pressure in the coolant and air lock...there was problem with thermostat that has been solved recently ( stuck open) but there was always air present in heater matrix that i have bleed several times and apparently succefully..now after thermostat change it is back - and  again i have bleed it (not completly yet)

 

but through all this i have noticed there is no pressure in the expansion tank when cap removed ( no hiss.. nothing) no metter if it was hot or stone cold?

i have never been loosing any coolant

i get immediately warm and then hot air through the vent (although set to 22) (outside now 0-2 C ) to extreme hot until the temp reaches 90 and theromstat opens ... then it levels

 

i also have/had some engine vibrations before bleeding ... maybe to related to the pump ...with air in the coolant?

 

so question - why there is no pressure in the coolant and whay does it get so hot through the vents before the thermostat kicks in?

 

thanks for any ideas

 

bleeding is done as it should  ( tank lifted and uper hose with bleed hole exposed ..)

1.9 115 BPZ engine

[Bigotts]

Hi I had similar issue with my old saab 9-5 3.0 tid 2002 I had sniff test done along with pressure test which resulted in exhaust gases in my coolant possible head gasket or cracked block are you loosing coolant ?

[pinstripe]

hi and thx for reply

 

i had done the sniff test ... and there is nothing that would point to that.

i am not losing any coolant and it had never overheated  - always stady at 90

lost...

[pinstripe]

anyone?

[Jigger72]

is this for an Octavia or a Superb? It's in the Superb I forum but your avatar says Octavia. Try the Octavia forum

[pinstripe]

no it is superb mk1 2007 1.9 115 - i have it now from march

before i had octavia - avatar changed  - thx

Edited 16 December, 2015 by pinstripe

[pinstripe]

to recap this ...in  this time i did several bleeding's with no result. Yesterday i did a core flush and there were a lot of rust cruds came out.

no it finally seams i have cured the swoosh sound it the dash.

 

but still no pressure when opening the cap from a expansion tank...

Edited 1 June, 2016 by pinstripe

[SuperbTWM]

Could be a faulty cap, but I would expect there to be a small amount of coolant loss as you get some evaporation.

[pinstripe]

Well, i did wanted to start at the cheapest fix if possible, so i have already replaced with new cap, with same result. And fact is, that i have no coolant loss.

There is no bloody hisss when i remove the cap. But maybe that is how it needs to be and it's a proper function - i don't know any more...

[SuperbTWM]

If there are no other issues apart from not getting a hiss from it when its warm I wouldn't worry too much

[pinstripe]

i am struggling to find out why is having excessive black smoke and and some not smooth running at 1100 1800-1900 and around 2500-2700 rpm - always at this rpm.

I did a vacuum leak test and find out it leaks a bit at the bottom of the dipstick (orange tube) when is connected to the engine block. - first i need to replace it and maybe this will sort the issue.

...the problem with no pressure in expansion tank may be connected to this. that is why i am not sure if it's OK or not, as is?

Edited 1 June, 2016 by pinstripe

[pinstripe]

Further....

today a had replaced the funnel (plastic tube) and it is 4/5 better ...but there is still some hisss (but nothing to worry about) due to the perfect engineering of VW - there is no O-ring where the tube is connected to metal.

i have checked the turbo too. I have taken off the rubber hose going to turbo and inspected the impeller and bearing for any play - but everything seams to be in perfect order. There is even almost no oil in the hose. Just enough to make your finger dirty.

 

So, with no more air in the cooling system and heater matrix, no vacuum leak, nothing wrong with the turbo and actuator rod in working order, i am still wondering why there is still

- excessive black smoke present

- no pressure in the cooling system

- not smooth running at 1100 1800-1900 and around 2500-2700 rpm

 

 

Can somebody help me with some pointers what to check next or what can be the most obvious thing to look for?

thanks