Hi,

problem with boiling water after 5-6 km of driving...temp gauge is about quater? No racing, just light driving about 70-90km/h, outside temperature 28°C.

When I arrived to garage, heater tank was like "balloon" and water was boiling. (temp gauge still under the quater).

When i turned off the ingnition, boiling raised! It boiled about 2 minutes.
Then I started engine, remove cap from heater tank and water is slowly rising up to the top of heater (cca 30sec up top). I saw bubbles comming out from pipe...but same bubbles I can see if I turn of the ignition so I am guessing that water is boiling inside engine (this makes bubbles) - But there is a question why is water boling inside engine? Car stays for a few years, Last year a cleand water system with 10pcs of cleaners (flush) there was a lot of "mud" in system...Any idea before I demount the thermostat and water pump?

Thanks! (sorry for my english)

 

So the Thermostat was dead....

but I changed it...and there is still some presuure in heater tank ( and bubbles when engine is running (hot)).

How can I check up 100% if the head gasket (or head) is OK? There is no OIL in water, no Water in oil...no white smoke...

And when I turn off the engine (hot) ..water is bubble from engine to heater tank - is that normal?

 

Mine was doing that, there was a loose coolant hose. It only boils when its not under preasure so theres preasure escaping somewhere

prohaps shine a torch and look for steam coming out somewhere.

 

If there will be loose hose.... = water leak...but there is no any water under the car

 

Get one of the rad sealant chemicals as they work well on tiny leaks

 

Maybe wrong cap?

 

Could be, and cheap enough to try.

 

you must fit a bypass thermostat
which looks like this

 

Mine wasnt loosing water it just couldnt hold preasure, the pipe was loose on the expansion bottle, I only notice cos when I touched the hose bubbles went in the the bottle

 

I changed cap of heater tank...now system is not pressuring (cap is working ) old cap was dead..... But when engine gets hot, water will blow out of the heater tank ....so I gues that head gasket is gone.....

 

So...I found a problem...

www.wi-telecom.sk/ecus/cossie/head1.jpg