Can Low Coolant Cause the Car to Shake? Plus 6 Other Causes!

Engine coolant is just as crucial to an engine running as the fuel is. But can low coolant cause the car to shake? Well, to get straight to the point, although the likelihood that low coolant is causing the vehicle to shake is very slim, low coolant can cause the car to shake. But it would need to be so low there is almost no fluid in the coolant system, and at this point, you’re causing damage to the engine. 

If you find your car is low on coolant, although probably not the cause of a car shake. It may be a sign of another problem, or it could be adding to the issues. 

If you understand coolant and how to top up the level safely, then topping it up would be your first action. If this is not for you, a mechanic can correctly fill your coolant before trying to diagnose further issues. But before I get into that and more, it would be wise to understand what coolant is and its role in the engine.

What Is Coolant?

Coolant, also called antifreeze, is a fluid mixed with water circling around the engine. Its function is to maintain the engine at the correct operating temperature. The process works by hot coolant coming out of the running engine, passing through coolant hoses, and reaching the radiator at the front of the vehicle. The air passing through the radiator core, provided by the radiator fan or the wind as you drive, cools the fluid. After this, the cooler fluid is pumped back around the engine bay via the water pump, thus keeping the temperatures down.

Another significant role of antifreeze is to prevent the fluid from freezing, which could render the engine inoperable in cold conditions. Thus, checking the strength of antifreeze in your vehicle during an annual service is vital.

Lastly, antifreeze protects engine components, such as the water pump and the motor itself, from rusting, as it contains corrosion inhibitors.

Can Low Coolant Cause the Car to Shake?

Dangerously low or no coolant in a vehicle could cause the car engine to shake. Almost no liquid in the coolant system would mean the engine could overheat, the engine temperatures would rise, and either the car would put itself into limp mode or internal engine components could get damaged, meaning the engine would shake. Limp mode stops the vehicle from accelerating correctly as it limits the engine power. If you have never experienced a car in limp mode, the check engine light will illuminate alongside the engine, stuttering and holding back, causing a shake as you try to drive.

To be clear, driving a vehicle slightly down on coolant, i.e., coolant still in the reservoir would cause no issues or future damage, provided it is topped up with coolant or water. This is why it is very doubtful that low coolant is the cause of car shaking.

What Would Cause the Car to Shake?

Car shakes can stem from various parts of a vehicle. While coolant is not a common culprit, other potential causes exist. If you notice your car shaking, it’s advisable to have a qualified mechanic inspect it to diagnose the problem correctly. If you feel confident enough to self-diagnose the issue, here are some possible causes:

  • Engine – The engine has many balanced rotating components that work perfectly with each other. Any engine internals with a minor fault throw the whole engine balance off, causing shuddering and shaking.
  • Transmission – Transmission components such as driveshafts can cause a car to shake when driving if slightly bent. Bending a drive shaft is not an easy thing to do, but a minor distortion will translate into a severe shake at high speeds.
  • Suspension – Worn suspension components such as ball joints, although they would usually knock over bumps, would also cause a nasty car shake.
  • Brakes – A brake issue will only be present when you apply the brake pedal. If the car shake is only under braking, several problems could be present in the braking system, such as warped braking rotors, seized calipers, etc.
  • Tires – An out-of-shape tire can cause the car to shake while driving. Imagine driving with a tire no longer round, more like an egg; when you get the car up to highway speeds, expect to feel the car shake.
  • Rims – A buckled rim will have a similar effect to an out-of-shape tire and cause the car to shake as you drive. When a wheel or tire is changed, they are balanced; occasionally, a balance weight comes off, and this causes an uncomfortable vibration through the steering wheel or seats. An unbalanced wheel vibration could be confused with a shake.

What Are the Signs of Low Coolant?

Apart from physically inspecting the reservoir’s coolant level, a light on the dashboard will indicate the coolant level is low. Otherwise, without a light, issues such as the temperature gauge on the dashboard reading high could signify an overheating problem, possibly caused by a low coolant level.

Another indication the coolant could be low is hearing the cooling fan on constantly; this could indicate the car is overheating, which could be because the coolant is low. A low coolant can also have the opposite effect, and the cooling fan may never operate. The low coolant level may be low enough to never reach the coolant temperature sensor, which signals the fan to switch it on.

Most coolant reservoirs have minimum and maximum level markings. With the engine switched off, the current fluid level is very easy to read through the side of the bottle. If the bottle is dirty, it isn’t easy to read the coolant level. If that is the case, shine a torch into the coolant reservoir to help determine the level.

Do You Top up Coolant?

Coolant needs to be at a required strength, depending on the climate. Topping up your coolant with either water will slightly weaken its strength, or antifreeze may mean it is too strong.

The engine must be cold before you do any testing or fill the coolant level.

Before just topping up coolant, it is best to know its strength before deciding whether to add water or coolant. An antifreeze hydrometer is a tool mechanics use to determine the coolant strength. Antifreeze strength testing strips are another tool that can be used. They are dipped into the coolant and read against a chart; both have the same outcome. Both will give you the temperature reading in which the coolant should operate. The ideal range is between a minimum of 34 degrees Fahrenheit (1 degree Celsius) to 265 degrees Fahrenheit (129 degrees Celsius) or higher.

The usual strength mix of antifreeze to the coolant is 50/50 with water. Sticking to a 50/50 mix without tools to test the strength and provide you with the correct type of coolant is essential. If the coolant has been the same for a long time, consider performing a full coolant flush. 

Engine off

Do You Put Coolant in While the Car Is Running?

Never put coolant in the vehicle while the car is running. The coolant system in a vehicle is kept under high pressure, so the coolant boils at a higher temperature. If you remove the coolant reservoir cap while the coolant is still hot, let alone while the car is running, the fluid would be exposed to atmospheric pressure, and therefore the coolant would immediately boil.

On a pressurized coolant system, if the cap is removed while the engine is hot, the pressure on the cap fires the coolant out into the sky, followed by scalding steam that spits violently. Hot coolant can cause severe burns; the heat of the steam from a coolant tank is enough to melt skin and, thus, a trip to the hospital.

The engine should always be cold when topping up the coolant. This is the only way to ensure you will not cause any harm.

Frequently Asked Questions

What Are The Causes Of Low Coolant In A Car? 

A leak in the cooling system can cause low coolant in a car, a blown head gasket, a damaged radiator, or a faulty water pump. It’s important to act quickly to prevent engine damage. 

How Do You Safely Top Up A Car Coolant Level?

To safely top up a car coolant level, follow these steps: park on a level surface, let the car cool, locate the coolant reservoir, check the level, add 50/50 coolant and water, start the engine, recheck the level, tighten the cap, dispose of excess coolant safely. Never add coolant to a hot engine; use the recommended coolant type for your car.

Bottom Line

The bottom line is that while a low coolant level can cause the car to shake, the likelihood it’s causing an issue is very slim. A shaking car would usually indicate a more serious fault on the vehicle. No mechanic would immediately check the coolant level if a customer reported a car shaking. However, although probably not the cause, it would be sensible to top the coolant level back to within the markers on the coolant bottle if it is low.

My name is Tom although my friends call me Tommy. Messing around with cars and bikes has always been a hobby of mine even from a young age. So I made it my day job 17 years ago. I am a fully qualified mechanic as you would expect. I've worked in all different areas of the motor trade, valeting, panel beating, engine repairs, I'm sure you get the idea. I enjoy sharing my wealth of knowledge and experience with others, which is the reason I spend a lot of time here writing for this website.

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