I have read two other threads that indicate a leaky head gasket for Nissan Frontiers overheating…but I’d like an opinion on my problem: I have a 1999, v6 3.3L, 4x4, manual Frontier that I have owned since 2001, always well-maintained, timing belt, water pump and thermostat already replaced a couple of years ago; currently has 129k mi. I rarely drive it (about once or twice a month). Last time I drove it (I’m in AZ and heat was over 100 degrees) it started right up and was fine until I’d gone about 3 miles on the freeway doing about 65mph. Started to climb in temperature, but not into the red zone. I drove with it hovering just above the midway point (midway meaning perfectly normal temperature on my gauge) for a couple of more miles, when it started to climb just a bit more, I got off the freeway and dropped under 45 mph, the temperature went down to normal. I drove about 40mph back home and haven’t driven it since. I checked my coolant, which was extremely clean and not low, and was not boiling when I checked it soon after the temp went up on the freeway. What is the most likely cause?
On a side note, since I do not drive it that often, what is recommended as to the gas that has been sitting in my tank since? How long does the gas stay good for? Further wondering how often it is recommened I drive it, for how long and at what sustained speed to keep my truck up and running?
For the gas, get a bottle of gasoline stabilizer (“Stabil” is probably the most common brand). But you will be better off just driving it regularly. Perhaps you can just work out a schedule - I’d probably drive it at least once a week and at least about 20 miles per trip. Short trips would be worse than leaving it sit.
I would make my next regular drive be to your best locally owned, independent “radiator shop” - or something like that. Many areas have shops that do specialize in the cooling system. What you describe can have different kinds of causes. A good shop will find the cause and fix it. You may be looking at something as simple as a bad thermostat and/or radiator cap; a little more expensive like a clogged radiator or maybe that “new” water pump is already losing its fins; and then there is the worst case which is a head gasket.
Look at your oil - on the dipstick & under the filler cap. If the oil looks something like a chocolate milkshake AND you are willing to dump some $$ into this vehicle then don’t drive it to a shop - have it towed. If you don’t want to spend any $$ on it, sell it. There are plenty of people who would buy something like this cheap, fix the head & drive on. Don’t expect to get much in that case.
But don’t start assuming the worst case scenario.
The first thing I would do is take a hose nozzle or an air hose and shoot the water or air stream through the radiator from under the hood and out the grille. You may have all kinds of debris blocking the air flow through the radiator. While this may not be the problem, it won’t cost you a thing and is worth trying.
The oil is clean and golden…