Heat related problem

Hi Guys,
I have a 2004 Nissan Frontier 3.3 automatic 4x4 with 232k miles. I am a rural mail carrier in Pennsylvania and use this vehicle on the mail route 6 days a week. I have a heat related problem with my truck. I can run this truck all winter long with no problems, however once the outside temperature goes above 60 degrees or more and I have driven my truck approximately 2 hours on the route my truck will start spitting and sputtering. It will idle fine but if I try to accelerate it will stall. After I shut the engine off for a short period (15 to 30 seconds or longer) and restart the engine - it seems to reset and runs fine for a random amount of time. I have to shut the engine down and restart at least 6 times or more on the mail route. I have had the O2 sensors on the passenger side replaced along with the gas cap. The problem existed before and after the fuel pump was replaced. Currently the truck is at the Nissan dealer. Last week they replaced the distributor($575.00) Needless to say that did not fix the problem. The error codes are for the O2 sensors and knock sensor. I was told that neither one of these would cause the problem that I am having. Any Ideas???

Thanks,

Dale

Are your radiator fans running when the truck is doing this?

Heat related issues like this most often point to the ignition system. I imagine this vehicle has either coil over plug or it has a coil pack. When electronic components begin to die…its is almost always when the temp rises. This is because of small cracks that can open up and leak voltage…esp high voltage like what we find in the coil packs. Do this…at night and in the DARK…get your engine nice n hot to the point of failure…look under the hood to see if you have any high voltage arcing coming out of the coil packs or wires or what have you on this engine. I have located MANY an issue by doing this and seeing the fireworks show that can present itself when a coil pack is giving up the ghost due to heat

Blackbird

hmmm … o2 and knock sensor codes? I agree w/H Blackbird above, sounds like an ignition system problem. If you get a spark when you shouldn’t you can get pinging, which will cause a knock sensor code. And that can also cause the o2 sensor reading to go haywire, b/c you aren’t getting complete combustion. That would also explain the sputter, as the engine is missing.

Beside what HB suggest, also consider the crank position sensor (CKP) as a cause. If you vehicle sports one I mean. Those are a common heat-related problem reported here.

http://en.wikipedia.org/wiki/Crankshaft_position_sensor

Edit: Camshaft position sensors and ignition modules also can exhibit this heat related symptom.