Valves: operation, maintenance and price

Valves are an important part of the proper functioning of your engine. They participate in its combustion. The intake and exhaust valves allow air to enter and exit the combustion chamber. Their opening and closing are controlled by the camshaft.

🚗 What is the role of valves?

. valves are the parts you will find in your car engine. When the engine is running, the valve is in motion. Thus, the valve has two positions: an open position and a closed position.

The valve consists of a stem, a collar, a head and a tail. The main role of valves is to ensure tightness the combustion chamber with an explosion of the air-fuel mixture.

There are two types of valves: valveinput и valveexhaust... An intake valve allows air to enter the combustion chamber, and an exhaust valve allows combustion gases to be released.

It is acamshaft which allows the valves to be activated. The valves open when pressed by the camshaft. The camshaft springs keep the valves closed by a mechanism that pulls them up.

Thus, air enters through the inlet valve and gases exit through the outlet valve. The valves are synchronized with pistons thanks to the movements of the camshaft and crankshaft which are driven by the movement of the pistons.

There are usually 2 valves per valve. cylinder, and we most often find on the engine 4 cylinders, which in total is 8 valves.

?? How do you know if the valves are damaged?

Like most parts in your car, the valve can be damaged and cause the engine to malfunction. Here is a list of the main symptoms that should indicate the condition of your valves:

• Do you hear clapping at the valves;
• You notice loss of power your engine;
• You are watching unusual fuel consumption.

Typically, if you see these symptoms, your valves may have two types of problems:

• The valve is bent : This often happens if your valve is in contact with the top of the piston. If so, it means your engine is no longer perfectly synchronized and the problem is likely with the timing belt. Don't put off going to the garage to check the valves because you risk damaging your cylinder head or pistons.
• Valve burned out : This is most often damage to the exhaust valves. A burnt valve is often the result of combustion gases escaping between the valve and the valve seat. To check for a burned out exhaust valve, look for possible excessive fuel consumption, misfiring, or reduced performance while driving.

🗓️ When to do the valve clearance?

Valve clearance is a measure that determinesdistance between valve stem and camshaft when the valve is in the closed position.

If the valve clearance is too large and the control of the valve opening causes noise, the engine performance is reduced because the valve opening time is noticeably shortened.

If the valve clearance is insufficient, it will cause unstable idling and difficult starting due to a leak in the valve.

In any case, the performance of your engine decreases and your fuel consumption increases. Therefore, it is necessary to adjust the valve clearance. This operation should be performed regularly or when these symptoms appear to prevent damage to other parts of your engine.

👨‍🔧 How to run in the valves?

Valve break-in is a complex operation that requires deep knowledge of mechanics. If you notice that your engine is losing power, your vehicle's valve may need to be broken in. Here are the basic steps to break your valves.

Required material:

• Toolbox
• Valve lifter
• Magnet
• Boer
• Abrasive pad
• Lapping paste
• Sucker

Step 1: access to valves

Accessing your valves can be tedious if you're not used to touching your car's engine. Indeed, you will have to drain the water from the cooling system, remove the hoses, and then the timing belt.

Then disconnect the inlet and outlet and disconnect the throttle cable and necessary electrical connections. Now it's time to remove the cylinder head. To do this, first unscrew the cylinder head screws, then remove the cylinder head. Then remove the camshafts.

Step 2: remove the valves

Use a valve lifter to make it easier to remove the valve. Then use a magnet to remove the crescents from the valve. Do the same for all valves.

Step 3: clean the valves

Before breaking the valves, you will need to clean them. A drill and an abrasive sponge can be used to clean the valve tulips. Also clean the entire cylinder head. This stage is long, but necessary, so that you can then carry out the running-in correctly.

Step 4: break the valves

For this step, you will need a lapping paste and a suction cup. Start by applying oil to the valve tail and drip the paste onto the tulip. Now you need to insert the valve into its guide.

Then place the suction cup over the valve and rotate it for about 30 seconds. Then you can remove the valve and then clean the tulip and scope. Check the spans until you get a uniform gray film. Finish the operation by cleaning the guides and rails.

Step 5: replace the gaskets

To maintain the tightness of the valves, the gaskets will have to be replaced. To do this, remove the damaged seal, then reassemble the new seal in the same place. You can use a socket and a hammer.

Step 6: assemble the valves

For this step, you need to rearrange the spring, replace the crescents, and reassemble the valve assembly.

Step 7: collect all the parts

After your valves are installed, reassemble all the parts you removed. Also remember to remove air from the cooling circuit. Your valves are now replaced!

💰 How much does it cost to replace the valves?

The price of the part is not very high: in specialized stores you will find valves for about the price twenty euros... However, labor costs can rise rapidly as valve access takes a long time.

Now you know what is the role of valves in your engine! To find out the exact price of valve replacement, you can go through our garage comparator and get a list of the best mechanics near you and at the best price!