Transmission not engaging lower gears, "Rev'd" in D

[Scotty C]

2007 Lexus LS460 w/192,000 

I took a 3-hour trip.  While in traffic on the interstate, when accelerating in D (not manual) the engine "revs", not engaging as if in neutral.   Shifted to manual to overcome, which seemed to work.  Cruised at 80 MPH for 3 hours.  Upon getting off the highway, the car would drive but it was as if It was starting in 5,6,7,8th gear...a very sluggish start.  Shifted to Manual (1st/2nd) which did NOT work.  No warning lights, no visible leaks, no smells.

When shifting into reverse, I detected a "thud" or non-smooth shift.  No way to check fluid since it's sealed.  I am in rural Illinois--nearest dealer is 90 miles away.  Called my dealer for ideas.  Short of a diagnosis, not much insight.

 

Need to make it back home which seems doable based on behavior.

Thoughts?

Edited May 10 by Scotty C
Grammar, additional content

[RX400h]

Quote

Here are a few possibilities:

1. Transmission Fluid Leak: Over time, transmission fluid can leak from your Lexus LS460, potentially causing transmission problems¹. A transmission fluid leak may be caused by a damaged transmission pan, faulty transmission cooler lines, worn-out seals, a cracked transmission housing, or an overfilled transmission.

2. Transmission Slipping: This is when the transmission fails to engage properly, causing the car to feel sluggish or the engine to rev without the car accelerating. This could be due to a variety of issues, including low transmission fluid, worn-out gears, or a failing torque converter.

3. Transmission Solenoids: These are devices that dictate when the transmission changes gears. It’s not uncommon for these to go bad after a while.

Given the symptoms you’ve described, it’s possible that the issue could be as simple as low fluid level, or it might require more extensive repairs. It’s hard to say for sure without a proper diagnosis.

Since you’re in a rural area and the nearest dealer is 90 miles away, you might want to consider contacting a local mechanic or an automotive service that offers mobile repairs. They might be able to diagnose the problem on-site and possibly even fix it without you having to drive the car to a dealership.

 

[Scotty C]

Following are the results from Microsoft Copilot:

The 2007 Lexus LS460 4.6L V8 does not have a transmission fluid dipstick. Instead, it uses a check valve on the bottom of the transmission. To check the transmission fluid level, follow these steps:

1. Ensure Safety: Park your vehicle on a level surface and engage the parking brake.
2. Warm Up the Engine: Start the engine and let it run for a few minutes to warm up the transmission fluid.
3. Locate the Check Valve: The check valve is typically located on the bottom of the transmission, underneath the vehicle. You may need to raise the car using a hydraulic lift or an underground bay to access it.
4. Remove the Check Valve Plug: Use a wrench or socket to remove the check valve plug. Be cautious as some fluid may drain out.
5. Check the Fluid Level: Insert your finger or a clean tool into the check valve hole. The fluid level should be close to the bottom of the hole. If it’s low, you may need to add more fluid.
6. Add Transmission Fluid (if necessary): If the fluid level is low, add the appropriate transmission fluid. The 2007 Lexus LS460 requires approximately 7.7 quarts or 7.3 liters of transmission fluid¹².
7. Reinstall the Check Valve Plug: Once you’ve checked the fluid level, securely reinstall the check valve plug.
8. Verify Proper Fluid Level: Start the engine, shift through the gears (from P to 2L), and then return to Park (P). Recheck the fluid level to ensure it’s within the proper range³.
9. Maintain Vehicle Level: Keep the vehicle level while adjusting the fluid level to ensure accuracy⁴.

Remember to use Toyota Genuine ATF WS transmission fluid for this vehicle. If you’re unsure or need assistance, consider having a mechanic perform the check for you. Regular maintenance of your transmission fluid is crucial for optimal performance and longevity of your vehicle.

[Scotty C]

The car normally operated all weekend, but upon heading home, the converse occurred.  The car would not shift into upper gears.  I thought I could "hobble" home at lower speed, albeit higher RPM.  About 12 miles on the interstate, the exhaust started to smoke (no surprise), then subsided

Pulled off, found an O'Relly's auto parts and they pulled the codes (attached).  Cleared the codes in hopes it might function normally.   I did NOT disconnect the battery per my mechanic over the phone.  I did not want to continue to trouble shoot with a call full of people and luggage.  So...I towed car back to highly acclaimed transmission shop--they open tomorrow.  Consistent with RX400h (Dave) and other research, the findings are similar.  Recall that there were no codes two days before.

9 Errors (attached) Solenoid's (pressure controls) (4), Shift (2),Transmission Fluid Pressure Sensor/Switch (1), Cylinder 6 misfire (1), System too rich (1).

I would like to understand the estimated cost and level of effort at a transmission specialist from this forum.

Starting to do a bit more digging now...  

Hopeful from rural Illinois 🙂

Note:  The family had two cars so we could bring things home from college.  We swapped the clothing for people, I sent my wife and 3 adult kids home.  I staying at my daughter's apartment while they look at the car, and reliving my college days 🙂

2024-05-10 Transmission Codes.pdf