5 Signs of Bad Intake Manifold Gasket (and Replacement Cost)

Your intake manifold does a lot of work and is a critical part of your engine. While the intake manifold itself is usually quite sturdy, the gasket seals between the manifold and cylinder head have been known to fail.

But how do you know if you have an intake manifold gasket leak and what does it mean if you have one? More importantly, how much will it cost to fix it?

We’ll break down everything you need to know here to fix this annoying problem. Let’s take a look at the signs to look for first:

The most common symptom of a bad intake manifold gasket is an engine not running properly and white smoke coming out of the exhaust. You may also notice external coolant leaks if coolant flows through the manifold. Mainly it will also display a check engine light on your dashboard.

Here is a more detailed list of the symptoms of an intake manifold gasket leak.

Intake Manifold Gasket Leakage Symptoms

1. Poor Engine Performance and Engine Skipping

A leaking intake manifold lets air and coolant out. Both things can negatively affect performance. It is not very likely that you will not be able to start your vehicle or that your engine will stall while you are driving, but you may notice a decrease in acceleration and fuel economy.

The main concern is that if the refrigerant mixes with the oil, you will not only lose the performance of the refrigerant, but the oil will not be able to function properly. This can cause excessive wear on many components and lead to costly damage.

You can also find ignition codes in the engine control module if you check the trouble codes with a scanner.

If the intake leak is very bad, it can fill the cylinder with coolant, causing your engine to stall and make it impossible to run. This is very serious and can seriously damage your car. Fortunately, it is not very common as most car engines are designed so that the coolant flows into the intake manifold.

2. Excessive white exhaust smoke

If you look at your intake manifold, you can’t see exactly what’s going on inside unless you wreck the engine, at which point you need to replace your intake manifold gaskets, whether they’re leaking or not.

Therefore it is essential to know how to solve this problem without disassembling anything. The easiest way is to start the vehicle and look at the exhaust. If there is an excessive amount of white smoke coming out of the exhaust, it is because your engine is burning coolant.

The only way coolant gets into the combustion chamber is if there is a leaking head gasket or intake manifold gasket; anyway, you have a problem. When determining whether the amount of white smoke is excessive, keep in mind that you will have more smoke in cooler weather than in warmer weather, and this is completely normal.

3. Coolant in oil pan

One of the most common problems with a leaking intake manifold is that you will find coolant in the oil pan. Unfortunately, this is also one of the most serious problems. Not only do you lose the cooling properties of the coolant, you also lose the lubricating properties of the oil.

When you combine these two problems, you quickly have a vehicle that needs an extensive repair to get back on the road. If you find coolant in the oil pan, take your vehicle to a repair shop right away. You can easily identify the coolant in the sump because the oil will look milky if you check the oil level on the dipstick.

4. Visible refrigerant leak

If you have a leaking intake manifold gasket, there are a few ways the coolant can go. First, it can enter the combustion chamber, where excess smoke is generated, or it can fuse with the oil, allowing coolant to be introduced into the oil tank. But it can also come off the side of the outside of the intake manifold.

If this is the case, excessive smoke may be emitted from the top of the engine if the coolant burns before it reaches the ground. Or you have a visible coolant leak on the ground under your vehicle. Either way, if you trace the leak back to the intake manifold, you’ve found your problem.

5. Motor Overheating

The three most prominent symptoms of a leaking intake manifold all relate to coolant leaks. Since the coolant’s job is to keep your engine from overheating, it’s not surprising that if it’s not working properly it can overheat your engine.

This won’t happen right away and usually happens when the system is out of coolant. But if you have an overheated engine and can’t figure out where the coolant is going, chances are it’s coming from a leak in the intake manifold.

Intake Manifold Gasket Function:

The function of the intake manifolds is to direct the correct fluids, gases and engine needs to the correct location in the engine. The intake manifold gasket helps with this by eliminating possible escape routes for these liquids or gases.

The intake manifold gasket forms seals around each of the passages in the intake manifold, keeping everything where it’s supposed to be. It may not sound that complicated, and it isn’t, but that doesn’t make it any less important.

Location of intake manifold gasket:

Your vehicle’s intake manifold gasket is located near the engine’s cylinder head between the intake manifold and cylinder head. With V-shaped motors, it is usually located between both heads. For inline motors, it is usually on one side.

It’s usually not that hard to get to the intake manifold, but there can be a lot of electrical components on top. Not only can this make it difficult to access the intake manifold, but it can also make viewing difficult.

Intake Manifold Gasket Replacement Cost

The average intake manifold gasket replacement cost is between $80 and $400 depending on the car model and labor costs. An intake manifold gasket costs between $30 and $100 and labor costs between $50 and $300.

The intake manifold gasket itself is often quite inexpensive, but most of the replacement cost comes from labor costs. This is because you have to remove the entire intake manifold to get to the gasket.

Sometimes the intake manifold will burst, causing a leak near the gasket, and in this case you can expect a new $200 to $800 intake manifold.

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