Car starts, gears change, car won’t go.

ANSWER : Hi and thanks for contacting Your Mechanic. If sometimes your vehicle will start with the new alternator and sometimes it won’t, then there is a loose connection in your charging system. Check all of the wires to the alternator and to the battery. Make sure that the battery cables are clean and tight. Make sure that the wires to the starter are clean and tight. A loose ground to the ignition system will cause the vehicle to not crank over. Check all of the ground wires from the battery to the starter. Make sure that they are clean and tight. If you need further assistance troubleshooting your no start situation, then seek out a technician, such as one from Your Mechanic, that can assist you.

ANSWER : Hello – your clutch hydraulics are the problem here. Check the clutch hydraulics fluid level – and it may share the same reservoir as the brake master cylinder (both use brake fluid as the hydraulic medium). If fluid needs to be added, that means that probably the clutch slave cylinder is leaking – this might be visible as a clear, but bitter-smelling liquid on the ground under the engine. I recommend a clutch hydraulics inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : If the clutch mechanism is releasing properly, and the shift linkage is not malfunctioning, your transmission will have to be removed from the vehicle and inspected. Once a transmission has been removed from a vehicle, if the problem is a broken or worn part or parts, and the transmission has 100,000 miles or more, the most cost effective approach is to just simply rebuild the whole transmission. There are transmission rebuild kits that are sold just for this purpose. Rebuilding a transmission is no big deal and is indeed easier in many respects than rebuilding an engine. You can rebuild your transmission right in your own garage. You can NOT rebuild an engine in your own garage due to the highly specialized, and extremely costly, machine shop equipment required. Occasionally, mobile mechanics will take on a transmission rebuild job especially as once the mechanic removes the transmission from the vehicle, it is just simply a modular unit that can be easily transported to a mechanic’s shop and rebuilt right there and then returned to your vehicle. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Your MAP sensor is an important input for your computer. It helps determine the load on the engine to calculate the correct amount of fuel to inject. It sometimes takes a few seconds for the vehicle to realize that the sensor is not producing a good signal.

At that point, it will use other methods to determine the fuel rate, such as pre-programmed fuel maps, throttle position, etc. I would suggest replacing the MAP sensor and retesting. If you would like to have it checked first, a certified technician from YourMechanic will be able to scan your vehicle and test components to determine the root cause of your starting issue before making a repair.

ANSWER : Hello, thanks for writing in. From what you describe, it would appear that your vehicle may be having transmission issues. The symptoms you are experiencing can be caused by a wide variety of things. A few common causes are a bad shift solenoid, a bad transmission valve body, or a faulty torque converter. As the possibilities could be many, I would recommend having a transmission specialist look at the vehicle for the best diagnosis.

ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hi there. This does sound like an issue with the wiring. If the check engine light is coming on every now and then this means that when it does not come on there is no power to the computer. This can be the wiring harness issue or an ignition switch problem. I would have to test for voltage to the computer when the problem is occurring to be able to find where the issue lies. If you need assistance, a certified YourMechanic technician can be dispatched to your location to inspect your vehicle’s non-start issue and suggest any necessary repairs.

ANSWER : Hi there. Check the shifter lock solenoid in the shifter housing. The lock solenoid may have an issue as the ignition key is on. I recommend replacing the shifter lock solenoid. Also, I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your lock solenoid in your shifter if your vehicle still continues to not going in into park after replacing the shifter lock solenoid.