asc325is
Active Member
- Joined
- May 27, 2020
- Messages
- 59
- Reaction score
- 13
- City, State
- Houston, TX
- Year, Model & Trim Level
- 2020 Explorer XLT 202A
Hey there. I have been chasing a rough idle/vibrations on cold starts for a while. Car is a 2020 XLT 2.3L with 102k miles. I have replaced the spark plugs, cleaned the throttle body, IAT and MAPT sensor with a little success but the problem persists. The air filter was changed with no effect. I usually run premium fuel here in Houston. The vibration is getting worse as the temps are (finally) starting to drop a bit here.
When started, the engine sits at ~1200 RPM in park. In gear, the vibration starts and the rpms drop to ~900-950 until the engine warms up, then they drop to ~700-750. I also noticed that every once in a while the engine needs an extra second or two when starting (cold starts only).
The engine smooths out like butter when it reaches operating temperature, there is absolutely no vibration so I don't think it's the motor mounts. I noticed last night that the engine seemed to stumble a bit when cold and in reverse with my foot on the brake. It kept running, but it wasn't pretty.
I am thinking that maybe the ECT is telling the computer that the coolant is colder than it is, causing the air/fuel mixture to be off. Has anyone replaced this on their own? The manual says it's on the cabin side of the engine, so not easy to get to...I am going to see if I can see it from below, but I think the transmission is going to make that impossible. I picked up a new ECT and a CHT2 sensor.
One other thing, it seems to be taking longer to hit operating temperature as well. Yesterday, the engine cooled off one "notch" on the dash while filling the tank. It took ~2 miles on the road after that to hit 4 notches. That's what is pushing me to something being off with the temperature.
Anyone have any thoughts?
When started, the engine sits at ~1200 RPM in park. In gear, the vibration starts and the rpms drop to ~900-950 until the engine warms up, then they drop to ~700-750. I also noticed that every once in a while the engine needs an extra second or two when starting (cold starts only).
The engine smooths out like butter when it reaches operating temperature, there is absolutely no vibration so I don't think it's the motor mounts. I noticed last night that the engine seemed to stumble a bit when cold and in reverse with my foot on the brake. It kept running, but it wasn't pretty.
I am thinking that maybe the ECT is telling the computer that the coolant is colder than it is, causing the air/fuel mixture to be off. Has anyone replaced this on their own? The manual says it's on the cabin side of the engine, so not easy to get to...I am going to see if I can see it from below, but I think the transmission is going to make that impossible. I picked up a new ECT and a CHT2 sensor.
One other thing, it seems to be taking longer to hit operating temperature as well. Yesterday, the engine cooled off one "notch" on the dash while filling the tank. It took ~2 miles on the road after that to hit 4 notches. That's what is pushing me to something being off with the temperature.
Anyone have any thoughts?
