I’m new to this forum but I’m seeking help here because no one else can figure out my car issues.
My wife and I have a 2011 Nissan Murano with ~140,000 miles on it. We don’t really notice any issues with this vehicle until we take it on 8+ hour long road trips. During these road trips our Murano will all of sudden be unable to get above 2500 RPMs at about hour 4 or so. This happens especially when we are going over mountain passes. To resolve our issue during the drive we stop at a rest stop, turn the car off, and wait 15-30 minutes and the car ends up being able to accelerate and go above 2500 RPMs just fine… This typically happens just once (sometimes twice) during our long road trips.
We have taken it to multiple mechanics and none of them have been able to identify what the issue is. They have inspected the transmission and they say the transmission shouldn’t be the issue. They also can’t replicate the issue. They have changed the transmission fluid but the problem still persists.
I’m interested in hearing what everyone’s opinions are on this issue and if you know of a solution.Thanks!
I think you have a clogged fuel tank vent. I think it is in the gas cap. If you have a long drive coming and the engine loses power, pull over and unscrew the gas cap to let air in. If the car then runs OK, replace the cap.
You think that’s it? Just let air into the gas tank? Is this the same thing as what Corollaguy1 mentioned? “vapor locked”?
Does this have something to do with how the engine is able to draw gasoline from the tank? and the engine can’t draw from the tank if the gas tank is a vacuum? Or is that incorrect reasoning?
Thanks!
Vapor lock occurs when the gasoline’s actual pressure falls below the gasoline’s vapor pressure point, somewhere along the fuel supply system. When this occurs, the gasoline changes from a liquid phase to a vapor phase and there are not enough gasoline molecules reaching the combustion chamber to maintain the proper air/fuel ratio. As a result, the engine does not run properly.
I wouldn’t call it “vapor lock” as I use that term for another condition but essentially it still applies to this situation.
That’s pretty much it. The tank is a closed system that keeps the fumes inside. A fuel pump in the tank pushes fuel to the engine and over time air needs to enter the tank to replace the fuel or a vacuum occurs and then not enough fuel can get to the engine. If that “check valve” fails, or sticks shut you get vacuum. If you sit for a while that vacuum bleeds off and away you go again… for 3-4 more hours.
I like yours and @COROLLAGUY1 's answer! I will be driving from Utah to Iowa for Thanksgiving and if we encounter this issue, which I’m sure we will in Wyoming, I will open the gas tank and drive on without waiting more than 5 minutes to see if that resolves the issue. I will report back on this thread saying if it works or not.
The transmission fluid is getting too hot, there may be a restriction in the transmission cooler or a problem with the cooling ability of the radiator.
High fluid temperature protection mode
This transmission has a high fluid temperature protection mode. If the fluid temperature becomes too high (for example, when climbing steep grades in high temperature with heavy loads, such as when towing a trailer), engine power and, under some conditions, vehicle speed will be decreased automatically to reduce the chance of transmission damage. Vehicle speed can be controlled with the accelerator pedal, but the engine and vehicle speed may be limited.
BTW the fuel tank is vented though the vapor canister, not the fuel cap.
I do remember one of the mechanics saying that the car could be going into some sort of safety mode… But they couldn’t confirm that. Nothing showed up in the computer code when they checked for it. This protection mode makes sense if it prevents the car from going above 2500 RPMs (which results in us not reaching very high speeds). This happens even if I floor the gas pedal. Do you think the protection mode’s mechanism for protection is to prevent the car from going above 2500 RPMs? or is that just a by-product of another mechanism that prevents the transmission fluid from over-heating?
AFAIK, Murano has similar issues, moreover, I’ve heard from the guy running transmission repair shop that Murano’s transmission is thermally overloaded in older models
I would strongly recommend using Nissan “premium” service schedule and replacing CVT fluid every 30K miles