I have a 2000 4Runner with 158K miles on it. Been a great truck with little trouble over the last 12+ years. Recently, the truck has developed a shudder. Initially, it was intermittent and confined to low RPM (<1000 RPM) situations usually right after ignition. The problem would go away after a few minutes of driving. I took the truck to the dealer and they could not find anything or reproduce the condition.
Yesterday, however, the problem worsened significantly. While driving at speed the shudder developed and the Check Engine blinked a few times. The problem went away and then reappeared about a half hour later. This time the Check Engine light stayed on continuously for the remaining hour of driving and it blinked a couple times as well.
Today, I drove the care back to San Francisco from Napa. The Check Engine light was lit the entire time, but the truck ran fine. Then, I parked it at home for a few minutes while I unloaded the truck. When I restarted the 4Runner, the light was off.
I am thinking the issue is related to ambient air temperature. The problem has been most severe in hot weather (90 degrees plus) in Sacramento and Napa. It seems to go away when I return to the cooler and damper summer climate of San Francisco.
Given that, I am thinking it could be a sensor problem (maybe mass air flow sensor) vs. an issue with the transmission/torque converter. Any thoughts her would be most appreciated. Thanks!
Yesterday, however, the problem worsened significantly. While driving at speed the shudder developed and the Check Engine blinked a few times. The problem went away and then reappeared about a half hour later. This time the Check Engine light stayed on continuously for the remaining hour of driving and it blinked a couple times as well.
Today, I drove the care back to San Francisco from Napa. The Check Engine light was lit the entire time, but the truck ran fine. Then, I parked it at home for a few minutes while I unloaded the truck. When I restarted the 4Runner, the light was off.
I am thinking the issue is related to ambient air temperature. The problem has been most severe in hot weather (90 degrees plus) in Sacramento and Napa. It seems to go away when I return to the cooler and damper summer climate of San Francisco.
Given that, I am thinking it could be a sensor problem (maybe mass air flow sensor) vs. an issue with the transmission/torque converter. Any thoughts her would be most appreciated. Thanks!
