I fitted a replacement V6 engine to my friend/customers car.
new thermostat fitted, with old stat the previous engine was running below 60 deg C.
this engine idles well, drives very well, temperature show a steady 90 deg C on the dial.
there was only one fan was working at low speed until i repaired 2 connections, now both fans operate at low speed
the 2 fans operate at the high speed
when I fill the reservoir to the max when cold, as the car heats up as the low speed trigger point the car expels coolant thro the green cap & when it then cools down the coolant level is lower than min.
Is that a sign of a defective head gasket or just a bad reservoir cap?
Rad is not leaking but afaik its the original rad.
TBH I donít know if its partially blocked but it was fully drained before re-fitting.
Any suggestion appreciate.
BTW: i have another rad to fit if necessary for testing.
If there is a head gasket gone how can you deciper which cylinder is leaking.... to calify ther eis no sign of oil in water or water in oil ... just wondering how to check.