Contour Enthusiasts Group Archives Forums Modifications Zetec Maintenance overheating when i flush out system

i just got my car yesterday and it was steady running in the L on the temp gauge
i see that all the Zetec's run a little hot so i went and bought some flushing stuff

well while flushing it and having the heater on (which was the first time for the heater to be on ) the dam thing goes to the little line after the l so i turn on ac and it goes down to the L

my ? is the heater stop blowing heat when it goes to the L

what could be wrong with it

Did u put water + coolant ??

Only coolant is not good... don't forget that water has excellent thermo properties.... and the coolant is only to protect against freezing and rusting.


After flushing mine, I felt a GREAT difference. It was running much colder. Then I changed the thermostat to 180F and the thing is running TOO COLD now

Temp gauge is all the time at "N" "O" on the "NORMAL" temp gauge. I hope that is not bad !!!

no i havent even got that far i am just using water only to finish the flushing process

but its not taking that much water now adn it is going past the l

i havent drain it again just waiting for the motor to cool down

i wll put mostly water in it since i doent have to worry about it freezing down here in texas

my ? is when you drain all the water then fill the expansion box should i keep the cap off so it can go into the rad better or just fill and put the cap on and wait till it all goes into the rad

okay.. let's come back: did u backflush it ?? (usually at a lube place)

Or are u just literally flushing it ??

Is the T-stat okay ?? Are u sure ??? Maybe wrong direction ???

just make sure the t-stat is ok... and if u r only flushing, I would recommend a back-flush in a lube place... it costs only $30 and it really cleans the whole thing.. they use steam water.

no i havent back flushed it

i bought a kit to do it just need to find the heatercore inlet hoes

i did use some prestone flushing stuff and it did help it is running at the A not the L
tommorow iam going to replace the t stat with a 180
then i will go from there

thanks