5 Leaky Intake Manifold Gasket Symptoms You Need To Know!

Five of the most prominent symptoms that your car has an intake manifold gasket leak. See how to spot a symptom, narrow down the cause and treat it.


Did you know that your car “breathes” too? Let me explain: Your car's engine needs oxygen to create explosions within its cylinders to drive the car. It is the role of the intake manifold to provide this oxygen. Coolant is also distributed to the cylinders in this way.

The intake manifold gasket is made of rubber or plastic and attaches the intake manifold to the engine. Due to strain from heat and the resulting contraction and expansion the gasket can get cracked. Coolant and air can leak through these cracks, heating up and suffocating your engine!

car under the sun

A typical intake manifold gasket:

Leaky Intake Manifold Gasket

Not only does this lead to less performance, but your engine will suffer damage in the long term. Let’s look at 5 symptoms of a leaky intake manifold gasket you need to know!

#1. Engine overheats or temperature readings jump

​There are a few different ways that you can detect whether your engine is overheating:

  • Check the gauge: You should have a temperature gauge on your dashboard close to the water and gas level indicators. The gauge usually has a red area in its arc that is the “danger zone”. If your car's temperature goes into this zone or hovers close to it even though you haven’t driven far, the engine is overheating. Similarly, if the temperature needle jumps around it might also indicate a coolant leak.
  • A burnt smell: When an engine gets very hot you will be able to detect a slight burnt smell. Usually as if rubber/plastic is burning. It is a good idea to check your car if you catch even a whiff.
  • Steam or smoke: Hopefully you detect something is wrong before it goes this far! If smoke or vapor comes out of your engine it’s a good indication that some damage is already done. Stop your car immediately and let the engine cool.
  • Strange noises: You might also hear some faint bubbling or spluttering noises. This is because of heated liquid that starts to boil and splash around the engine parts.
Woman repair car

Read this article for some more signs that your car is overheating.

#2. Engine does not perform as well

Unlike the coolant that we want to keep in, a gasket with a crack or leak let’s too much air get sucked in. When there is too much air in the cylinders, not enough gas is let in. This leads to weaker explosions, which affects the speed of the pistons and the power of your engine.

  • You will especially be able to feel the difference when you accelerate. Push the pedal down and if your car does not react like it used to, pauses before acceleration or accelerates irregularly it might be a sign of a leaky gasket.
  • Another sign is if you leave your car to idle. If the car idles too fast or even stalls completely. This is because the car no longer knows how to correctly regulate its idling speed with the leak.
  • If you listen carefully you will also hear faint popping sounds, this is called “backfiring” and is also a sign of a leak
the man repair the car

​Starting your car, letting it idle and listening is a good way to pick up many different warning signs.

True, all these symptoms can have many different causes. Keep reading to find out how you can detect a leak and confirm whether it is the cause.

#3. Higher fuel consumption

Because of the number of misfires and the decreasing power of the engine, it will need to use more and more fuel to keep going. You will most likely also accelerate harder and harder to try and drive as fast as you usually do.

In the beginning, the difference in petrol usage might be too small for you to notice, but as the crack gets worse and your engine performs less and less it will become more apparent. If you drive roughly the same distance every week you might see your tank draining faster than usual.

the mechanics fix the car

If you are lucky and your car displays an average fuel consumption it will noticeably increase.

There can also be many different causes for higher fuel consumption, like improperly inflated tires, bad wheel alignment or other engine problems. You will need to look for an air leak to know it is your intake manifold gasket.

#4. Coolant leaks

The easiest way to know that your car is leaking coolant is to check for an oily puddle underneath the front of your car. But how do I know if it is coolant or something else?

  • Engine coolant comes in many different colors depending on the brand. If you still have some coolant try to find it and compare it with the spill.
  • Touch the coolant. It should have an oily feel, but not as oily as engine oil, more like shampoo or soap. It should also wash off easier than motor oil.
  • Coolant should have a sweetish smell.
Coolant leaks, She opened the jar

Now that we have established that it is coolant that is leaking, we need to find out where it came from. The intake manifold sits right on top of your engine. It should look kind of like a bridge with multiple metal tubes on each side. If the coolant leak is coming out where the manifold and the engine meet it is most likely caused by a damaged gasket.

The coolant can also come from many other sources:

In this video, you can see the man look for the coolant leak at all the usual places and finally find that it is his intake manifold gasket that's the source:

#5. Vacuum air leaks

While coolant leaks lead to the engine overheating, air leaks lead to reduced performance. If your car suffers from one or more of the symptoms mentioned, it’s worth checking out.

As you can imagine finding the air leak is not as simple as looking for an oil spill. Lucky for you, we are going to show you a few tricks to find an air leak!

Before you begin, inspect all the rubber hoses and fittings leading to your engine for cracks or tears first! You might be lucky and find the culprit before you inspect the gasket.

Vacuum air leaks


Method 1: You will need a bottle of carburetor cleaner, water in a spray bottle or starter fluid to attempt these next steps.

  1. Start the car and let it idle for a while. Listen closely to what it sounds like.
  2. Take the carburetor cleaner and spray it where the intake manifold is attached to the engine.
  3. While spraying, listen closely to the car's idling. If it idles faster, almost as if you are softly “revving” the engine, or becomes smoother then you know the gasket is faulty.

To check many other parts of your engine, or just to locate where these parts are, follow this handy guide using the above technique. In this video, the mechanic helpfully takes apart the engine and shows you exactly what happens:

So, what should I do now?

​The good news is you can fix small leaks at home. Some mechanics do not believe in these solutions and they are easy to mess up, especially since they are only suitable for very small leaks. If your problems return it’s best to go for a gasket replacement, immediately.

​Cool down overheated engine:

If your engine overheats while you drive there are some quick steps you can take that might allow you to drive home or to the nearest service station:

  • Stop the car.
  • Turn on the heat to full and let it blow, open all the doors and windows.
  • Wait for the engine to cool before opening the hood.
  • Open the radiator cap when it is a safe temperature to touch or use a cloth.
  • Add more coolant, or if you don’t have any, some water.

IMPORTANT! Do not touch any hot parts with your bare hands. Wait for the engine to cool down. Safety first.

Here is a complete guide to temporarily cool down your engine if it overheats.

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​Here are the steps:

  • Make sure the engine is shut down and has cooled.
  • Open the radiator cap.
  • If you have a small or normal sized vehicle add less than a bottle to the radiator. If you have a big pickup truck you will need a little more than a bottle.
  • Make sure that your water, coolant and radiator levels are all correct.
  • Start your car and let it idle for 15min.

​Here are the steps:

  • ​Make sure the engine is shut down and has cooled.
  • You must find the exact area of the leak using the steps above.
  • Press some of the sealant to the area of the leak. Let it dry for 15min.
  • Remove the ignition coils, here is a video to help you.
  • Attempt to start the car a few times for short moments.
  • Put the ignition coils back in place

If the problem persists

Unless you have a lot of experience fixing cars mechanically, you should call the professionals! Replacing an intake manifold gasket not only mean you need to determine the cause, find the leak and buy the right gasket. You will also need to remove the intake manifold from the engine and replace the gasket without any leaks. This requires a level of experience and skills.

If you are brave enough, here is a step-by-step how-to guide

The mechanic is repairing the car

Did you find this list helpful? We hope so! A leaking intake manifold gasket can cause you as a car owner (and driver) a lot of problems, that’s why it was important for us to share this information with you. We hope that you never face this problem, but if you do you now have the knowledge to do something about it!

If you have any helpful information to add or just want to share your opinion on this article, please comment it below. Remember to share with your friends if you enjoyed it and think it can help them too.


Hi there! I’m Jordan, chief editor of Crush the Road and I’m a self-confessed automative fanatic. Cars or vehicles has always been a passion of mine and will always be my favorite pastime. Now that I am married and has one adorable son, I have the time to write and share my personal experiences with other automative enthusiasts like me. Welcome to my fantastic blog!

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Avatar for james
james - October 12, 2020

i got odd probem first i found intake bolts lose wich was giveing me bank 2 running to lean i found bolts lose just out mistake, so i get them down and all the codes gose away, but one odd reading all the 02 sencros voltage is all over the place, all but one it sets at.015 but when i rev the car will match rest of the sencors, can this make car run odd when at higher speeds sounds like hard explane, but i taken to shop they told me drive line probem but why was not the error codes even check would u not start there at the computer,
there was flash done on car but when was done it had a bad battery, i wounder if a bad battery could damage the upload, car would start fine but voltage could not be mantain, or is o2 sencor is damage, should not the voltage be close to other side, but reading at ,015 at idele dosent make lot sence, as none rest like this, i put some clearner in it thinking carban might be factor, as when u rev car sencor starts working, what is your thinking 2014 dodge charger v8 himmy, also i read that changeing compotents while battery is on would lead bad driveing conditions if lot was change, could computer be wrong in how reading the system lot diffrent quistions, but each is imported as i may have unhook the battery for few hrs and then let computer rediscover all devices,


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