Q: Engine light came on after washing engine 2 days later then went off and oil lamp came on three times - driving - went off.

Well, you have a couple of questions here and not a lot to go on, so I’ll address them as best I can. Your Check Engine light indicates that a trouble code from a sensor has been registered in the engine’s computer. You’ll need to have a certified technician, like one from YourMechanic, connect a scanner/code reader to the car’s diagnostic connector to inspect what trouble codes have been stored. Trouble codes are a starting point for any technician; in most cases, simply replacing the sensor that sent the code will not remedy the problem and it’s necessary to "look past" the code to get to the root cause.

If your oil pressure lamp is coming on after washing the engine but you haven’t previously noticed problems like knocking or valve noise, or haven’t seen the oil lamp come on before, there’s a good chance that the engine wash caused a short in your oil pressure sending unit or its associated wiring or connectors.

As for whether the Jeep is worth more investment, Kelly Blue Book puts the resale value of an ’04 Jeep Liberty at about $3,500. You’ve replaced a lot of parts, including a new transmission, so if the vehicle is reliable and solid right now it may be worth holding onto it for awhile longer. If you have to keep replacing parts at this point, though, you may be reaching the point of diminishing returns.

If you need assistance with this, consider YourMechanic as one of our mobile technicians can diagnose your car’s Check Engine and Oil Pressure Light firsthand to avoid any unnecessary repairs. Best of luck to you!