Nissan Repair: 1991 300zx 2+2 non turbo, head gasket leak, upper radiator hose

Question
I have a '91 300zx non turbo which overheats an trips longer than 45 mins. Runs fine with no overheating in city driving conditions.
I am probably going to replace the radiator. Need to find out where the thermostat is and how to remove & replace it.
Also just in case I have a small head gasket leak,do you know anything about an additive called Steel Seal and is it any good?


Answer
Roman,

Follow the upper radiator hose to the engine and that is where the thermostat is.  Use a stock Nissan unit.  I have not found an aftermarket thermostat that I like as much as Nissan.  If you are going to keep the car replace the headgaskets instead of using sealants.  They plug up a lot more than just the leak and then you have to take everything a part to get the system cleaned out.  Well, that is my experience on block sealants.  It is worth a weekend of pain doing the headgaskets.  There are two bolts on the thermostat housing and it is simply a removal and replacement.  Get the gasket from Nissan along with the thermostat.