The consequences of camshaft failure can range from a simple misfire to full-on engine failure.
The cost of replacing a camshaft can vary depending on the make and model of the vehicle and the type of camshaft being replaced. Generally, the average price of an actual camshaft ranges from $300 to $1,000, but labour is very intensive. You can expect a camshaft repair cost to be between $2,000 and $3,000 labour costs included depending on the mechanic. A few things can affect the cost of a camshaft and belt replacement. One is the type of engine. For example, a V8 engine will have more engine parts, and the labour cost can be more intensive to replace the camshaft than a four-cylinder engine during car servicing. The other major factor is the make and model of the car. Some cars have very specific and proprietary camshafts that need to be replaced with an OEM part, which can be expensive. Aftermarket parts are generally cheaper but may not fit as well or perform as well as OEM parts.
A camshaft works in conjunction with the crankshaft connected to the pistons. It opens and closes the valves in your engine at just the right time for optimum efficiency and performance with the help of the camshaft position sensor. It's an essential part of your vehicle's internal combustion system.
Generally speaking, replacing a camshaft takes around 4 hours for an experienced tech. If you want to fix it yourself, it's a fairly straightforward DIY job. You should expect to spend about half that time, but you should allow yourself at least one full day to get the job done right. It takes so long because of all the other components that need to be removed to access the camshaft. For example, suppose your car has overhead cams, which is common in most fuel economy vehicles. In that case, you'll need to remove things like your intake manifold, gaskets, valve covers, cylinder head, cam lobe and timing belt. This is usually indicative of failing camshaft lobes or bearings. A compression test can also be done to check for low compression in cylinders, which a bad camshaft could cause.
Car owners experiencing any of the following problems should pay their mechanic a visit.
Rough idling.
Reduced power when accelerating.
Trouble starting your car.
Overheating of moving parts under load.
Excessive ticking or knocking noise when the engine is running.
Engine fault codes indicating a misfire.
Excessive noise when the engine is first started up after being parked overnight.
The consequences of a bad or failing camshaft can range from a simple misfire to full-on engine failure. Depending on how severe the car repair is, you might notice some rough idling, reduced power when accelerating, dead miss, trouble starting your car (especially after it's been sitting), overheating under load (like climbing a steep hill) or even backfiring through the intake manifold or exhaust pipe. If you experience any of these symptoms, it's usually a common sign for a camshaft replacement.
No, a new cam will not make your car go faster or perform better. A camshaft alters the torque curve of an engine, so it produces more power at a specific RPM range. It does not provide any power itself. Often, people mistake a loud sound from their engine for more power. In reality, a louder sound usually means a loss of power due to the inefficiency in the valvetrain system leading to more fuel consumption. A new camshaft will only make your car go faster if installed in a car that already has the necessary supporting modifications, such as a high-flow exhaust and engine tuning. Otherwise, you will likely see no performance increase at all.
In most cars with overhead cams, you usually have between 80,000 and 100,000 miles before your camshaft will need replacement. Vehicles that tend to work well past this mileage are generally factors such as driving conditions (stop-and-go city driving vs highway driving), car service schedule or if the car is being used for purposes other than what it was designed for. Follow the scheduled maintenance intervals in your car's owner's manual by doing basics like checking the engine oil and spark plugs regularly. You can save money and help extend the life of your camshaft and avoid engine replacement. Camshafts are one of the most important components in an engine and should be replaced when they start to show signs of wear on engine cylinders. In most cases, this will be around 80,000-100,000 miles depending on service providers.
There are three main types of camshafts: solid, hydraulic and rolling lobe.
Solid cams are the oldest type and are made from a single piece of metal. They are generally the least expensive and have the shortest lifespan in the long run.
Hydraulic cams use oil to help adjust the valvetrain and have a longer lifespan than solid cams.
Rolling lobe cams are a newer design that uses small rollers to help adjust the valvetrain. They have the longest lifespan, are the most expensive repair parts compared to any camshaft, and are considered the most reliable.
An overhead camshaft is a type of camshaft located in the engine head above the valves. This rotating object uses pushrods to activate the valves instead of a timing belt or chain. Most modern cars have overhead cams, and they are considered to be more efficient than other types of camshafts.
The main difference between SOHC and DOHC systems is that a SOHC system only has one camshaft for all of the cylinders, while a DOHC system has separate cams for each cylinder bank. This reduces weight, cost, complexity and creates an even firing order. With timing belts or chains, this type of setup has less slack than other camshafts, so valves are less likely to collide with pistons if the timing chain fail.
Most modern car engines will be either SOHC or DOHC, but some older cars may be classified as SOHC, like in the case of a V-6 engine that has two camshafts to activate all six valves (three for inlet valves and three for exhaust valves). More advanced cars models will have DOHC engines to provide optimum performance at higher RPM ranges.
SOHC uses one camshaft for all intake and exhaust valves. A timing chain or gear drives the camshaft(s), typically allowing a narrow overall engine design without giving up useful cylinder head area at a lower cost than DOHC engines. SOHC designs offer reduced complexity compared to overhead valve (pushrod) designs, with a single camshaft that operates all valves in the head.
DOHC uses separate intake and exhaust camshafts for each bank of cylinders. This allows more complete optimisation of the valve timing and increases power and fuel economy. The design is also more forgiving of mismatches between cylinder bore spacing and the crankshaft centreline. The use of two camshafts also allows the engine to be designed with more valves per cylinder, improving performance. The Queensland Government has a handy guide for automotive repair.