Five Signs That Your Intake Gasket Is Bad (& How to Replace It)

The intake manifold is an important part of the engine. It does a lot of work. The intake manifold is usually quite sturdy but the gasket seals that connect the manifold to the cylinder head can fail.

What does an intake manifold seal leak mean? What is the cost of fixing it?

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

Gasket leak symptoms in intake manifold

A bad intake manifold seal is most noticeable if the engine doesn't start properly and there is white smoke from the exhaust. If coolant has escaped from the manifold, you can see external coolant leaks. It will usually also display a check engine lamp on the dashboard.

Below is a list that explains the signs and symptoms of an intake gasket leak.

1. Poor Engine Performance & misfires

Leakage in the intake manifold can let coolant out, and air out. These two things could negatively impact performance. It’s not very likely that you won’t be able to get your vehicle started or that your engine will shut off while running, but you might notice a drop in acceleration and fuel economy.

The biggest concern is that if the coolant mixes with the oil, you’re not only losing the performance of the coolant, but the oil won’t be able to function correctly either. It can cause excessive wear to many components, and expensive damage.

A scanner can also be used to scan for misfire code information in the engine control module.

Intake leaks can cause a cylinder to fill with coolant. This will render your engine unable to turn. This can cause serious damage to your vehicle. It is rare, however. Most car engines have been designed so that coolant can flow into the intake manifold.

2. Exhaust-related white smoke

When you’re looking at your intake manifold, you can’t exactly see what’s going on inside unless you tear apart your engine, and at that point, you should replace the intake manifold gaskets whether they were leaking or not.

That’s why it’s essential to know how to troubleshoot this problem without taking anything apart. It is easiest to turn on your car and inspect the exhaust. If there is an excessive amount of white smoke coming out of the exhaust, it’s because your engine is burning coolant. 

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

3. Oil Pan: Coolant

One of the most common problems of a leaking intake manifold is that you’ll find coolant in the oil pan. It is also one the most serious problems. Not only are you losing out on the cooling properties of the coolant, but you’re also losing out on the lubricating properties of the oil.

These two problems can combine quickly to cause a vehicle that is unable to be driven again. You should immediately take your vehicle to the shop if you discover coolant in your oil pan. You can easily recognize the coolant in the oil pan because the oil will look milky when you check the dipstick’s oil level.

4. Visible Coolant Leak

The coolant may leak from an intake manifold or gasket. The coolant can be injected into the combustion chamber. This is what causes excessive smoke. It also can mix with the oil to create coolant in your oil reservoir. However, it is also possible to escape the intake manifold's side.

You might notice excessive smoke from your engine's top if coolant is not burned off. You might also have coolant leaking from underneath the vehicle. Either way, if you trace the leak back to the intake manifold, you’ve found your problem.

5. Overheating Engine

A leaking intake manifold is characterized by leaking coolant. Since it’s the coolant’s job to keep your engine from overheating, it’s not surprising that if it’s not working correctly, you can get an engine that overheats.

This won’t happen immediately, and it usually occurs once the system runs low on coolant. But if you have an overheating engine and can’t figure out where the coolant is going, there’s a good chance that it might be coming from a leak in the intake manifold.

The Intake Manifold Gasket Function

Intake manifolds are responsible for directing the proper fluids, gases, and other engine needs to the right place in the engine. By eliminating potential escape routes, the intake manifold seal helps to accomplish this.

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

Installation of the intake manifold gasket

Your vehicle’s intake manifold gasket is located near your engine’s head between the intake manifold and the cylinder head. For V-shaped engines it is typically located between both the headers. It is usually located to the side of inline engines.

Reaching your intake manifold usually isn’t too complicated, but there can be many electrical components sitting on top. It can be difficult not only to reach the intake manifold but also to see.

Gasket for Intake Manifold Replacement

The cost of replacing an intake manifold gasket is anywhere from $80 to $400 depending on your car's make and model. The cost of an intake manifold gasket is $30-100, and the labor price is $50-$300.

While the gasket for the intake manifold is typically quite affordable, labor costs make up most of the cost. To reach the gasket, you must remove the entire intake manifold.

The intake manifold can crack and leak, in which case you should expect to pay $200-$800 to replace it.

FAQ: Intake Manifold Gasket