I have a 2003 nissan xterra which is overheating. I've tried changing the thermostat but thats not the problem

Question

what could be the problem?

Answer 1

Several thing can cause overheating.
The Fan belt may be loose
The water pump may be leaking
The radiator may be clogged (unlikely but possible)
The timeing may be off
Blown head gaskets
Clogged exhaust

Answer 2

NEVER replace any part till you know the problem. Open the hood and with the engine at operating temp. see if the fan or fans are running. If not check the coolant temp. sensor located where the top radiator hose connects to the engine, where you put the thermostat. Turn on the a/c and the fan should start. If so you will know the fan and relay are ok. If fan is ok you probably have a radiator partly plugged. Go to a RAdIATOR shop, not an auto repair, and have them check it out. Stay away from dealers.

Answer 3

how do you know it's overheating?
does the temp gauge rise into the red or does the coolant boil?
is that the 3.3L? or the 4cyl both have fan clutches on them.
does the engine take a few minutes to overheat? or does it take a hot day and 2 hours of driving to overheat? when you changed the thermostat, did you bleed the cooling system correctly?
there is a bleed/fill screw towards the left(drivers) rear of the intake manifold that should be removed when filling the c-system (on the 6cyl.)
oh yeah, and the area between the condenser and the radiator has a good chance to accumulate dirt and debris and should be checked.
need more info from the customer.

Answer 4

Nissan Xterra Overheating

Answer 5

this can alsoo be the water pump going bad on it,the fins on it that circulate the water will wear out,and the pump wont leak any ,it just wont pump water good,it can also be a radiator getting stopped up on it,the get clogged up in the bottom,and wont let the coolant go through it real good,this causes the vehicle to run hot,id check those things out,,it will probably turn out to be one of them,als check the cooling fan on it,good luck with it.