billitman7

I have a 2000 Maxima with a 2001 engine. Ever since the engine was replaced a year ago, the car has been overheating when driving for extended distances in hot weather only. In the winter there is no problem. HOwever, the weather has been unusually hot lately, and the car easily shows the thermostat at maximum. The thermostat has been replaced. This problem seems to be worse going up hills, and I do find the temperature actually decreasing when going downhill only to jump back up when going uphill. I use regular gas - 87 octane. When the temp rises the car blows hot air inside even with the temperture set to low (65 degrees). I hate to bring it to the dealer and have them try all kinds of things and charge me an arm and a leg only to find no problem. I am at a loss. By the way it does appear that both fans are blowing on the radiator and still I experience this problem. Please help. Thanks!!

s32bn1bge1

Have you checked for a clogged radiator? It looks like 01 and 02 Nissans are having a problem with this. Look at the Pathfinder forum. We owners may need to let Nissan know of this problem in one loud voice.

blackpete

sounds like a clogged radiator have it checked.do you run good coolant in it.
the vq30 and vq 35 engines have 10.1 to 10.5 compresion ratio and like to run
priemium ulp (95 ron )if you are running standard ulp the knock sensor detects this and
retards timming to eliminate knock.i have a 98 max with the vq30 definatly does not like
87 ron .ive towed a campervan in 42 C heat with aircon on and does not overheat.
i run nissan gen,coolant mixed with distilled water and have never had radiator or over
heating problems for years.

brianw

Are you running standard coolant, either the usual standard green stuff or the Nissan coolant? I'm not sure how compatible long-life coolants are with Nissans; I've heard of GM-spec Dex-cool being run with success but my sample size isn't large enough.

When you had the engine replaced did you have the coolant passages in it inspected for rust and blockages?