The engine of your Prius can shake for a number of reasons. It can be a misfire, damaged motor, or transmission mounts. Broken parts inside the engine, broken crankshaft pulley or dislocated hoses or belts can also cause the vibration.
How to fix the Prius engine shaking when starting? Put simply, you can do it by repairing or replacing the responsible components. You might need to change the full engine if the problem is severe. For parts like pulleys, belts, or hoses, you might need to do a reattachment.
The vibration of a car affects the attention of the passengers, which can lead to accidents. So pay attention to today’s article on Prius engine shaking when starting causes and fixes.

Prius Engine Shaking When Starting: Causes And Fixes
First, let’s look at the causes of why the engine of your Prius might be shaking at the start. Afterward, we will check out the fixes to this problem.
Possible Causes of Prius Engine Shake at Start
Here I am discussing seven reasons behind the engine shake of your Prius:
Misfiring Engine
If the combustion process doesn’t get enough materials to complete, then it’ll cause the engine to misfire. This can happen due to the following:
- Improper and untimely mixing of air and fuel
- Faulty and erroneous sparks created by malfunctioning spark plugs
- Insufficient and inaccurate compression
- Unorganized internal components
A misfire causes may cause the Prius engine to shake due to improper engine operation.
Defective Motor Mounts

Motor mounts carry the engine of a car. Moreover, it’s a crucial part of tackling engine shakings. That’s because its rubber core separates the other components from the engine’s vibration.
Hence, one or more malfunctioning motor mounts can ruin the above-mentioned process. In other words, the engine won’t get enough assistance. And you might encounter noticeable shakings and noises in your Toyota Prius. This will get severe in bumpy areas.
Faulty Transmission Mounts
The transmission mounts work in the same way as the motor mounts. Especially when it comes to tackling vibrations.
Hence, a worn-out transmission mount can also cause the engine’s unusual movement. This is due to the fact that the engine and transmission are welded together.
Internal Engine Breakdown

This is a terrifying scenario. If parts of the Prius engine get broken due to technical issues, those parts can get stuck inside the engine.
Hence, the running engine will cause these parts to turn around. This will cause misfires and severe knocks. Spiral bearings on connecting rods are one of the main reasons for this situation.
Broken Crankshaft Pulley
The crankshaft pulley minimizes the vibration of the engine block. So whenever there is damage in it, it‘ll cause the engine block to move unusually. At some point, the block can break because of it.
Dislocated Hoses

Your Prius engine can be shaken violently and vibrated by a dislocated air hose. The dislocation causes a vacuum leak. Hence, the elimination process of the byproducts is interrupted.
This results in the misfiring of the engine. In other words, the engine starts to shake on a random basis.
Dislocated Or Faulty Belts
There are different types of belts in a Prius, such as
- Timing belt
- Spiral belt
- V-belt
Parts such as fans driven by belts will not operate as they should if the belts are faulty. As a result, the engine will make strange noises and vibrate.
How to Fix Prius Engine Shaking?
Now we will discuss how you can fix the above-mentioned issues in the Toyota Prius Engine.
Problem | Fixes |
Misfiring Engine | Ensure a proper mixture of air and fuel. Repair or replace damaged spark plugs. Organize the inner engine. Compress properly. |
Defective Motor Mounts | Inspect your Prius by a well-versed technician. Take immediate action. according to what the technician says. |
Faulty Transmission Mounts | Follow the instructions of a technician. You might need to replace the mounts in most cases. Don’t take matters into your hand. |
Internal Engine Breakdown | Consider replacing the engine in this scenario. If it’s possible, then you can ask any mechanic to fix the broken parts. Fixing the broken parts will be impossible in most cases. This problem should be fixed faster. |
Broken Crankshaft Pulley | Examine the condition. Replace the pulley if there are cracks. It’s not possible to repair a pulley. |
Dislocated Hoses | Look for any potential leaks or loose connections. Attach them properly. |
Dislocated Or Faulty Belts | Ensure that the belts are tightly attached. If there are cracks, replace them. |
Is A Shaky Prius Engine A Big Problem?
Yes, of course. There are parts connected to this problem that can cause serious accidents. Moreover, if it’s neglected, the repair cost will go up gradually.
In other words, you might need to give up on your Prius engine at some point and buy a new one. So beware of it.
Leave a Reply