QuestionThank you in advance for answering my question.
2000 Infiniti I30t, Auto, 93K mi.
When ambient temp is about 95 deg F, A/C On, and driving up a 2.5% grade in OD @ 80 mph, I noticed my engine temperature gauge needle rises from normal (steady state) to almost to H in about 20 seconds. I shut the A/C, still driving on the incline, and the temp needle lowered to just above normal after about 10 seconds. I then started to descend downhill, A/C off, in OD @ 70 mph, and the needle slowly declined to normal. This was last Friday at around 1700 hour.
For the past two days at around 1700 hour, the ambient is about 85 deg F. Under the same driving conditions, my temp needle didn't move up at all even with the A/C on (A/C temp set at 72 deg F).
I changed my coolant about 5 months ago with Prestone 5/150 extended life. The radiator cap looked OK with no debris behind the rubber gasket. The rubber gasket feels pliable and no tears. About 3 months after I changed the coolant, I had to fill the overflow tank and the radiator once with about 1 quart of 50/50 Prestone 5/150. I didn't notice any leaks. Ever since then, I haven't needed to add any coolant.
I checked both of my electric fans and they were turning on when the A/C is turned on. I also parked my vehicle near the off ramp after the temperature excursion and open the hood. With A/C on, both fans were on. I parked my car and shut the A/C and both of the fan was still on.
What could've caused the engine temperature gauge needle to rise?
If it's the thermostat, is the thermostat easily accessed right inside the housing where the main hose is connected on the passenger side? Is the NISMO thermostat (opens at much lower temp?) worth the extra $40?
If the NISMO radiator cap (much higher pressure) is installed, will it cause the water pump seals, hoses, radiator to fail prematurely?
AnswerLou,
Change the thermostat and go to Nissan and get a factory one along with a new radiator cap and install. The thermostat is easy as it comes with a new neck and is already installed in it. Be sure to get a gasket. Only two bolts and it is where the upper radiator hose connects to the engine. After that you should be fine. If you have not changed all the hoses the sooner the better. I bought all new Nissan hoses for the wifes Maxima for under $200 bucks.
