So my wife has a 98 Infiniti QX4 (chromed pathfinder) its got the 3.3 v6 4x4 and auto trans with 232k miles. Runs great trans even shifts smooth picked it up for $900 to use as a winter beater. Well its the only thing we have that fits more then 3 people and she had some family fly into an airport 4 hours away because it saved them several hundred dollars on tickets. So of course she decided we are gonna drive her quarter million mile SUV. Trip there and back the first time went great and we drove it all week throughtout the black hills putting another 1kmiles or so on it. Pn the way to drop them off I drove the first half and then she drove the rest of the way to the airport while I slept. When we switched off at the airport i noticed the temp gauge pegged on high and her ultra gauge was reading 266*!!!! So we drove imediantly to a car wash about a mile away hosed it down let it cool off refilled the radiator and decided to put the hood in the back for better airflow just incase because it was 103 outside. The rest of the trip we had to pull over 6 times to let it cool down.


I already checked for leaks and for symptoms of blown head gasket but didnt see anything so I think the thermostat isnt opening Im going to check that when she gets home tonight.


My question is how bad is 266* that seems outragiously high since water boils at 212.

 

The coolant raises the boiling point.

But 266 is very very high, you might get lucky and it's something simple but popping a headgasket is more than likely.