Bad shaking and grinding

ANSWER : Hi there. From the description you have given, your vehicle shakes over 40 mph. The first thought would be the tires like you’ve mentioned. Typically vibration (shakes) are due to something that is out-of-balance. Given the tires and wheels have been balanced, it could be a wheel bearing vibration, as a worn, loose, or bad wheel bearing could cause shaking. It could also explain the noise getting louder as you accelerate.

This could also be an out-of-balance axle shaft, as worn cv joints (attached to each end of the axle shaft) typically creating a clack-clack-clack noise while turning. To get a precise diagnosis, you can get in touch with YourMechanic to inspect the noise in person and follow through with any repairs that are appropriate.

ANSWER : When you say you have three bad sensors I can only assume you have had them tested and the end result is three bad sensors. If they tested bad then they should be replaced. The power steering sensor senses the load of the steering on the engine so it can raise the idle during parking maneuvers. The O2 sensor is used for fuel control and it may effect engine power and fuel mileage. The camshaft sensor cay cause no starts, engine running problems and all three will turn on the check engine light.

ANSWER : Hi there. Check the fuel pump relay to see if its activating. This sounds as if the fuel pump relay is having an intermittent sticking off condition. The relay may be getting too hot and shutting off causing the pump not to turn on allowing your engine to starve its self from fuel. Replace the relay if you find it not working properly. If you need further assistance with your engine running rough an intermittent occasions, then seek out a professional, such as one from Your Mechanic, to help you.

ANSWER : Hi. The symptoms you describe could be a dirty or malfunctioning idle air control valve. Especially when hot, when the engine gets a leaner mixture of air and fuel, the idle air control will have a greater effect on idle and low speed running. In general, it will not set a Check Engine code either. I would recommend having a rough idling diagnostic completed by a mobile professional mechanic, such as one from YourMechanic, to inspect the problem and replace the idle air control valve if needed.

ANSWER : Hello. The bad coil wouldn’t have caused the crank sensor to fail. Crankshaft sensors are the most common failure on this engine so it should just be a coincidence. I would use a scan tool just to make sure that there is no rpm reading before replacing it though, as there are some other problems that can occur, but are not as likely. If you need help with this, consider having a technician from YourMechanic come to your home or office to diagnose this problem with a scan tool and replace the crankshaft sensor if necessary.

ANSWER : Hi! That "sluggish starting" (slow cranking speed) is the most common symptom when a battery is at the end of its life. The age of your car is also just about in the normal range for how long batteries last. You are correct that it is very unlikely to be a failing starter. Here’s the good news: many automotive service businesses will test a battery for free (or close to it); it’s one of the least costly things to have wrong with your vehicle; it didn’t leave you stranded. I suggest having it tested today! If you’re trying to avoid having your car in a shop, consider YourMechanic, as a certified technician can come service your battery at your home or office to fix this issue.

ANSWER : Hello there. Typically jump starting a vehicle doesn’t trigger an OBD-II error code. However, one of the most common misdiagnosis issues with the P-2270 is replacing the O2 sensor before diagnosing if there are any exhaust leaks. Obviously, you’ll want to check for the exhaust leaks first, repair the damaged component, and then clear the codes before scanning the vehicle again. Sometimes the electrical harness attached to the O2 sensor is damaged or dirty which will also trigger this error code. The noise and vibration may be an indicator of a loose exhaust pipe, which may be the source of the error code staying on. If you need any help, have a technician from YourMechanic come to your home or office to diagnose your Check Engine Light and make the necessary repairs.

ANSWER : If the shaking is occurring with the car stationary, that would not involve the wheels or driveshaft, although it could implicate the torque converter. A shaking engine diagnostic would start with the motor mounts. If those are judged solid (there are tests), one should assess the mechanical condition of the engine by checking cylinder compression.

The reason for that is if cylinder compression varies too much, that variance alone can account for this symptom. If the cylinder compression is too low or varies too much from high reading cylinder to low reading cylinder, one would then try to rule out easily repairable items like a mispositioned timing belt or chain. Of course, if compression issues are traced to valve train problems, the heads have to be serviced.

Other potential causes of the vibration are a broken harmonic balancer, engine ignition timing being off, and flexplate and/or torque converter damage or imbalance. Prior to getting involved with diagnosing an imbalance in something as hidden as the torque converter, though, the engine should be put on a scope to determine if there is something going on in individual cylinder firing conditions that would account for the vibration. Varying power output from individual cylinders, due to possible fuel and ignition system problems, obviously will cause vibration: you could have a bad coil, plug, injector, and so forth. A scope makes that diagnostic easy.

I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the engine is shaking and suggest any necessary repairs.