Engine runs wells and RPMs are steady until I get on the highway and get above 50 mph then it will jump from 1500 rpm to 2600 rpm immediately. Even with slight pressure to the accelerator it won’t move until I have to push until it jumps to 2600 but it tops out there. Even when I set the cruise control it can’t find a steady cruising rpm and I will fluctuate at the 1500 and 2600 rpms. Any ideas on the issue?
Sounds like a slipping clutch. Manual or Auto transmission?
Car year, mileage?
And engine option.
It’s a 2001 with automatic trans, with 128000 miles and a V6 engine
Sounds like your lock-up torque converter clutch may be slipping.
Can also be a misfire under load. If an engine isn’t producing enough power, your transmission will downshift to maintain speed. I had a van that I thought had 100,000 mile pugs and I had about 79,000 on it. I thought had a transmission problem because it was downshifting for hill it used to take in high gear. It turns out the plugs were supposed to be changed at 60,000 miles. New plugs and no downshifting.
Can you turn overdrive off and test?