Why Car Makes Gurgling Sound When Idling or Starting?

Have you ever been driving and noticed a gurgling sound coming from the car? If so, you’re not alone. This is a common issue that many people have reported experiencing.

car gurgling sound when idling

If your car is making a gurgling sound, it could be for one of many reasons. The sound can be caused by a lack of oil or coolant in the engine. It might also be because you have air trapped in the cooling system and need to release it.

Whatever the cause, here are some steps that will help you identify and fix this problem so that your car runs smoothly again!

Why Car Makes Gurgling Sound When Idling?

If your car is making a gurgling sound when it’s idling, there are several possible causes. One possibility is that you have a leak in the cooling system, which is allowing air to escape and mix with the coolant. However, this is a sign of a blown head gasket, cracked engine block, and bad radiator cap as well. So, let’s dive deep into this-

Engine Overheating

For an inefficient cooling system, the engine can overheat and cause the coolant to vaporize and make a gurgling sound. The gurgling sound due to an overheated engine can be heard when the car is accelerating, idling, or starting.

Having a low coolant level or insufficient oil in your engine could also cause this issue as well because it will create a lot of heat which your cooling system won’t be able to manage. This may result in loss of power and overheating which causes damage to seals, pipes, and other components within the cooling system.

Radiator Fan Has Gone Bad

If your radiator fan isn’t working, it will cause the engine to overheat and make a gurgling noise. You can usually identify this issue by checking if the fan is spinning or not.

Bad Water Pump

Another reason why you might hear gurgling noise from the engine bay is because of a bad water pump. If your water pump is going bad, it will cause a lack of coolant circulation and the engine could overheat as a result which causes this gurgling sound to appear.

Incorrect Radiator Fluid Level

Another common cause of this issue is having an incorrect radiator fluid level or air bubbles trapped in the cooling system.

This occurs when there’s a leak in the radiator, water pump, or heater core that allows coolant to escape into the engine oil and lower its level too much.

Cooling System is Clogged with Particles

Another possible cause of this issue could be having particles such as rust and dirt stuck inside your cooling system which will block the flow of coolant and water. This will cause your engine to overheat and make a gurgling noise.

Air Trapped in Power Steering Fluid

If there’s a leak in your power steering line or the fluid level is low, you’ll have air trapped in the system which will cause it to make gurgling noises.

Blown Head Gasket

One of the most severe causes of a gurgling engine is when you have a blown head gasket.

This means that the gasket between the engine block and cylinder head has failed, which will allow coolant and oil to mix together. If this goes undetected, it can cause serious damage to your engine.

Cracked Engine Block

Another rare but serious cause of a gurgling engine is if your car has a cracked block. This means that the core or bottom part of the engine can’t hold coolant and oil anymore which will result in loss of power and overheating within the system.

Bad Radiator Cap

One final possible cause of a gurgling engine is having your radiator cap fail. This means that the seal between the top and bottom part of it breaks which allows air to enter or leave without you knowing, causing bubbles in the system.

Expansion Tank Causes the Sound

If your car has an expansion tank along with the traditional cooling system, it’s normal to have some gurgling sound. This is not an issue, rather a normal with systems of this kind.

How to Fix a Car that Makes Gurgling Sound When Starting or Idling?

There are several ways to solve the issue you are facing. The most effective being the bleeding of the whole coolant system, we’ll go over all the steps that you may need to follow to get rid of the annoying gurgling sound from car dash-

Flash the Coolant System

This is the most effective way to solve the issue. You need to bleed the coolant system thoroughly by removing the bleeder screw so that all air gets out of the system and then, fill the cooling system up to the recommended level. This should remove air bubbles from the system, resulting in bubbling sound or gurgling free ride.

Replace the Bad Radiator Fan

If you believe that the engine radiator fan is bad, it’s a good idea to replace it as soon as possible to restore the normal operation of the engine cooling mechanism. You can do this by opening up your hood and locating the fan. Once you’ve found it, remove the bolts or screws that are holding it in place and install the new one.

Replace the Bad Water Pump

If you are sure that the water pump might be bad, it’s a good idea to replace it as soon. You can do this by opening up your hood and locating the water pump. Once you’ve found it, remove the bolts or screws that are holding it in place and install the new one.

Make sure not to pour dust into the cooling system while removing the old or installing the new water pump.

Replace Head Gasket

In case the problem persists despite following all the processes of bleeding the cooling system and replacing the bad radiator fan or water pump, you may have to replace the blown head gasket with a fresh one. We recommend consulting a professional mechanic regarding this as you may do more harm than good if you are inexperienced.

Replace Bad Radiator Cap

If the radiator cap is bad, you can replace it by buying a new one from your nearest car parts store. Once you have the new one, remove the old one and install the new one following the manufacturer’s instructions.

How to Fix a Car that Makes Gurgling Sound When Accelerating?

If you experience gurgling sound only when you accelerate, then it’s probably the inefficient cooling system or air trapped inside.

Either way, you’ll need to check what has gone wrong. If the cooling system isn’t efficient enough to dissipate the heat away from the engine, you may need to perform a coolant system fix by a professional mechanic.

If it’s just air trapped in the cooling system, simply bleeding the coolant should do the trick for you.

Gurgling Sound in Car Dash, What’s the Reason?

This actually caused by the same reasons we have discussed in the first section. When the sound is loud enough, it feels like the sound is coming from the car dash rather than the engine bay.

So, following the process I have described above should solve the gurgling sound in car dash as well.


If you’re experiencing a gurgling sound in your car, there are several possible causes. From the radiator cap to the water pump and head gasket, this article should help you troubleshoot your issue so that it goes away for good!

If all of these options seem daunting or outside of your skillset, we recommend following our blog as we are covering up the relevant topics more here so that you feel confident doing any type of fix.

Leave a Comment