Dear Briskoda community,

I have a lovely Skoda Octavia 2.0 petrol MK1 2001 which is using too much coolant. The coolant in the reservoir  drops 10mm (ish) every month. The car does not overheat, It does not leak, I have pressurised the cooling system and it hold pressure greatly. I have tested the coolant in the reservoir for combustion fumes to check is head gasket let any through and this is fine. I am now thinking about the oil cooler... am I right thinking that if it leaks here coolant level drops (slowly)? Did anybody experience similar issues? Thanks

Heater matrix? Housing for the thermostat or CTS?

 

Mine had a small leak from the coolant temperature sensor (CTS) housing, new housing fixed it. It wasn't obvious that was where it was from initially.

Thanks for the reply, thermostat housing was leaking (cracked) and  CTS o-rings have been replaced then. As I was there I have replaced pipes going into heater matrix plus I have kept the system under pressure and i did hold! A I am stuck, so annoying knowing something is wrong but you do not know what!

I had the sensor housing go on my Mk1 Octi 1.6 as per attached photo. Is that the part you replaced? Cost me about £35 IIRC

 

My Mk1 always lost a little coolant, probably similar amount to yours. It never bothered me to be honest and fortunately never got any worse. I Had the car for 12yrs. My solution was to carry 1L bottle of coolant  in the boot and check the level before every journey.