My cadillac devail Shaking while driving som of the tim

W age of car..mounts probly worn as well as steerin parts . If shakes wile drivin then tires or balljoints bad..this can b dangerous..u can buy good used tires but b joints can collapse rite on interstate. Seek an old school mech and not a dealr

I bet it shakes under light/moderate acceleration and will also stop shaking if you let off the gas?

If so your best bet is to bring it to someone who is very good with driveline. It is fairly common for worn drive axles to cause this symptom however an engine misfire will also cause a similar symptom.

at 45 miles an hour overdrive engages putting a lot of load on the engine. Weak ignition components can cause a misfire that only shows up under this extreme load. It is very important to have somebody who is very good at solving these issues take a look at it and determine exactly what it is. I have literately had customers admit defeat after installing every ignition component, every sensor, and even transmissions only to find out a few hundred dollar drive axle was the problem.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

A bad rotor would only cause a shake when you are using the brakes. A bad tire could shake at 55mph and above.
I would get a second opinion to make sure.
The shop could rotate the tires and see if the vibration moves to a different area of the car.

If I understand you correctly it seems like belt "b" came off. If in deed it came off it is possible that it did som damage to the crank sensor and now since the computer doest have an rpm reference the vehicle won't start. You may have to revisit the work done and make sure everything is in order. Keep in mind this is an interference engine. Meaning that misalignment of the cam and crank or a belt coming off or breaking while everything is in motion will cause internal damage to the engine. Good luck.

If the car is running well, the issue could be a motor mount. A bad motor mount will give you the symptom of vibrating or shaking.

You need to check the choke on the engine for cold starts it chokes off air to the fuel mix . if it is closed to much the engine will want to die and shake. When the car warms up the choke opens and the car gets air and runs fine although the choke could just be part open. It still will need adjusting.

Hope this helps

Mike

could be an ignition problem,plugs,wires,coil pac,have system checked.










TIM..........

would suggest having the timming checked could of broke the timming chain.

The timing belt is not easy but the regular tune up anyone with basic hand tools can do.Plugs and wires,fuel and air filter and perhaps an oil change and your good to go.Timing belt should be done by som eone with experiance.

Have a cylinder leakdown test done...likely they missed another bent valve. I'm betting it's an exahust, because it would be less drivable if it was an intake, but regardless, I'll bet that is your problem.