Symptoms of a Blown Head Gasket in Vehicles

by Contributing WriterUpdated June 12, 2017

You have to love those crazy Bavarians. From Vehicles service literature on replacing the head gasket in an Vehicles "Clean sealing faces of cylinder head and crankcase; if necessary, remove traces of sealing compound with hardwood spatula. " Seriously -- how many other auto manufacturers would think to advise the use of a hardwood tool Vehicles anything? This says a lot about Vehicles emphasis on proper assembly and maintenance technique, especially where the critical head gasket is concerned.

Under The Hood:

 Symptoms of a Blown Head Gasket in a 3.0 Toyota

Engine Overheat

A blown head gasket causes the Toyota's 3.0 engine to overheat. As engine oil leaks into the coolant system through the blown gaskets, coolant efficiency is reduced and results in excess heat. The driver will notice this as a persistent climb in engine heat while the Toyota is running which spikes when the vehicle is idle. Toyota pickups and 4Runners with the 3.0 engine find it impossible to tow or carry excess weight without the engine overheating rapidly.

Abnormal Emissions

Toyota owners will notice white smoke emitting from the exhaust system from a vehicle with a blown head gasket. This is due to burned oil mixing in the engine block and being consumed as fuel. Alternatively, exhaust emissions may be sweet smelling which is the result of coolant mixing with fuel in the engine which may also occur with a blown head gasket. These symptoms greatly effect fuel economy for vehicles using the Toyota 3.0 engine.

Coolant Leaks and Damage

According to, head gaskets in Toyota vehicles using the 3.0 engine are particularly susceptible to head gasket failure via normal wear and tear from heating and cooling the engine. As cracks and breakages appear in the gaskets, the driver may notice changes in his vehicle's engine oil such as viscosity or color. These changes are more than likely from coolant leaking through the gaskets and into the oil pan, causing a breakdown in oil effectiveness and ruining the engine quickly.

 Symptoms of a Blown Head Gasket in a BMW E36

Rough Idle and Acceleration

BMW's straight-six engines are world-renowned for their sewing-machine smoothness. So, any kind of misfire resulting from a blown head gasket will prove more immediately noticeable on a BMW straight-six than on most other engines. If all is running well, you'll almost never feel a modern Bimmer straight-six at work; as such, even feeling the engine running at idle or under hard acceleration is generally an indication that something has gone wrong. And you should notice a difference in acceleration, particularly at high rpm where the BMW engine usually does its best work.

Fluid Crossover

The cylinder-head-to-block interface is one of the few places in your engine where the coolant, fuel, oil and exhaust can all come into contact. Depending on where the head gasket blew, you may get all kinds of fluid crossovers. Coolant emulsified in the oil will turn it into something resembling chocolate milk, and oil in the coolant will float to the top and form a rainbow-colored slick. Gases leaking into the crankcase will cause a puffing exhalation from the oil-fill cap with an accompanying raw fuel odor.

Clean Spark Plugs

On an E36 straight-six, the cylinder head deck isn't shot through with coolant passages as it would be on most other engines. Instead, the Bimmer engine's primary coolant passages are at the front and the back of the block. So, if the head gasket blows out around a coolant passage, water is only likely to go into cylinders one or six. Pull the spark plugs on the engine and very closely examine the plugs from the end cylinders. If one of them seems noticeably cleaner or newer than the others, it's because they've been steam cleaned by the leaking coolant.

Other Symptoms

Depending on where it blows, a blown gasket can cause overheating and coolant loss, as well as excessive oil consumption and colored smoke coming from the exhaust pipe. Gray, blue or black smoke and an odor of antifreeze or raw fuel are all indicators of a blown gasket. But you may get none of this, depending on the blowout location. In those cases, you'll only experience a loss of power, some engine roughness and a check-engine light. Checking the codes, you'll almost certainly see at least one misfire code stored in the computer. It won't be a random misfire code; instead, you'll likely see misfire codes for either a single cylinder or two adjacent cylinders.

 Symptoms of a Blown Head Gasket in a Dodge Caravan

Coolant and Oil

If you suspect your Dodge Caravan has a blown head gasket, keep an eye on the coolant and oil. If you notice the oil is frothy or has white bubbles when you're checking the oil with the dipstick, this is a sign that coolant has mingled with the oil. Also, if you check the coolant overflow container and find dark swirls in the coolant, this is another sign that oil has mingled with the coolant. Either symptom is caused by a blown head gasket, which normally keeps the oil and coolant in separate areas of the engine.


The exhaust exiting your Dodge Caravan can help you determine if the head gasket has blown. Oftentimes when the head gasket blows, engine coolant gets into the engine's cylinders. The heat inside the cylinders causes the coolant to boil and turn to steam, which is then sucked out of the engine along with the exhaust fumes. Normally, vehicles will have a white cloud of exhaust when they first start running on a cold morning. If your Caravan always has a white exhaust cloud coming out of the exhaust pipe or if the exhaust smells sweet, this is an indication the head gasket on the vehicle has blown.


A loss of power from the Caravan's engine can also point to a blown head gasket. Because the head gasket helps keep the engine sealed tightly, once the gasket blows, air can be introduced to the engine through the opening. With this extra air, the engine cannot burn the fuel as efficiently, leading to a decreased power output. The Caravan may struggle to go up hills or reach freeway speeds when before it had no problems.

 Symptoms of a Blown Head Gasket on an ATV

White Smoke

If a head gasket is blown on a liquid-cooled ATV engine, it can leak antifreeze into the combustion chamber. Once ignited, it leaves the exhaust pipe in the form of white smoke. This looks similar to when you first start your ATV in cold weather, except it does not go away after the engine warms up.

Antifreeze Leaking

When a head gasket blows on a liquid cooled engine, antifreeze leaks out from between the mating surfaces of the cylinder head and the engine block precisely where the gasket has blown. If the fluid does not flow into the combustion chamber, it runs down the cylinder and onto the crankcase. A visual inspection of the cylinder and crankcase can tell you if the head gasket has blown.

Fluid Levels

In rare instances, the ATV will mysteriously loose antifreeze but it will not show up in the form of smoke or leaking. Generally, you will notice this when checking the radiator fluid level. This typically means that the antifreeze is leaking into the oil pan. Drain the oil from the oil pan and inspect it for antifreeze. The antifreeze will separate from the oil and be noticeable.

Oil Leaking

When the head gasket blows on an air-cooled engine, oil could leak into the combustion chamber and when it ignites, the engine will produce black smoke. The amount of black smoke increases as the engine accelerates. If the oil does not leak into the combustion chamber, you will likely see oil on the cylinder and crankcase as it leaks from the head. Black smoke could also mean the piston rings are worn out. If oil is not present on the crank case, perform a compression test to determine if the oil consumption is due to a leaking head gasket or worn piston rings.

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