Blown Intake Gasket Symptoms

by Darla FerraraUpdated July 12, 2023
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The intake gasket provides a seal between the intake manifold and the cylinder head in a car's engine. Intake manifold gaskets are subject to extremely high temperatures and pressures. A blown or bad intake manifold gasket can cause havoc in an otherwise healthy car engine, but the symptoms can be difficult to detect if you’re not familiar with engine performance or signs of a blown head gasket. Many are ambiguous and can represent different problems, like a vacuum lead, bad air-fuel ratio, a leakage, or other performance issues. If you suspect that you have a faulty intake manifold gasket, look for some general clues that might prove you right.

Here are some common symptoms of a bad intake manifold gasket that might indicate that you have a vacuum leak and might need an intake manifold gasket replacement.

External Leak

Coolant may seep out of the broken gasket and flow across the outside of your engine. You will see orange coolant dripping under the frame of the car onto the road or driveway. A bad leak will cause a big puddle. With a small leak, the coolant may not make it that far, but there still could be a couple spots under the car. There may be a metallic smell as coolant evaporates off of a hot engine block. Dripping coolant may pool under the housing of the thermostat.

Internal Leak

Coolant may flow through the gasket to the inside of the engine and mix with the oil. Pull the oil dipstick out and look at it. Oil mixed with coolant will have a thick consistency. Examine the oil filter cap for any rusty-looking residue.

Excessive Coolant Loss

If you are adding coolant to your system, it may be leaking out through the frayed gasket. The need to add coolant often can be a sign of a blown gasket.

Overheating Engine

Engines overheat when they do not have coolant. If your gasket is blown, the coolant will leak out and the engine will overheat.

Rough Idle

Your engine may idle roughly, and you may hear whistling or sucking. This is air being pulled through the leaky gasket by the engine. While the transmission is in "Park," you may feel a slight rocking or tremor as the engine idles. To verify this, get a small propane gas cylinder from a hardware store. Let the engine run and squirt a tiny bit of gas along the edge of the manifold joint. Gas will go through the leak and the engine speed will rise temporally. This indicates that a leak exists and gives you an idea of the location.

Other Signs

Here are some other things to look for that might indicate an intake manifold gasket leak:

  • Look at the temperature gauge on your dashboard. Chronic engine overheating is a common symptom of a blown gasket. Your engine temperature should not be in the red or you might be leaking coolant.
  • Turn the car off and let the engine cool down completely. Open the hood and remove the coolant overflow tank cap. If you hear a pop, this means the cooling system has remained pressurized even while the engine is cold, which can be an early sign of a blown gasket.
  • Remove the radiator cap and start the car. Let the car warm up and rev the engine. If your gasket is blown, air bubbles will travel up from the radiator.
  • Watch for white smoke or water drops coming out of the exhaust pipe. Sweet smelling white smoke coming from a warmed-up engine indicates a coolant leak, a symptom of a blown gasket.
  • Check the engine coolant. A sudden drop in coolant level with no apparent leaks also indicates a serious coolant leak, which can be a sign of a blown gasket.
  • Check the engine oil. If the oil on the dipstick looks milky or frothy, or if there is a milky ring around the oil cap, this indicates that coolant is leaking into the oil pan, another sign of a blown gasket.
  • Pay attention to how your car feels while driving. An engine misfire or an engine that runs sluggishly or idles roughly may have a blown gasket. Stalling may also indicate that your automotive has an air leak and that airflow may indicate a bad head gasket.

Just because there’s no check engine light doesn’t mean your car runs without any problems – stay proactive to ensure good fuel economy and fuel efficiency and lower replacement costs in the long run in the combustion chamber.


Helpful comments on this video:

  • Happens for Toyota / Lexus with 3.5L . Will throw P0015
  • how would you go about fixing it, i dont have 1500 to blow on my old 2005 Cadillac Deville

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