Cylinder head / cylinder head gasket defective? The info!

Reading time 6 Min.

The symptoms of a defective cylinder head gasket/cylinder head. How is it repaired and what are the costs? A brief overview: The cylinder head sits on top of the engine block and closes off the block at the top. So that the whole thing is tight, there is a seal between the engine block and the cylinder head Cylinder head gasket. There are various things in the cylinder head, such as the intake and exhaust ports, the valve control, the injection nozzles or injectors and, if present, the spark. However, the cylinder head and the associated gasket can wear out with age or be damaged, for example if it has to be replaced overheating came. If there is a leak in this area, problems can arise with the lubrication and cooling of the engine. In the worst case, with the result: engine failure.

Symptoms / signs

• White or blue smoke comes out of the exhaust.
• There is heavy oil/cooling water consumption in a short period of time.
• Exhaust gases get into the cooling system. (workshop work with CO tester)
• The error memory says: "Combustion misfires, cylinder X".
• The engine oil gets into the cooling water circuit, which can be recognized by the darker / milky cooling water.
• The cooling water gets into the oil circuit, which can be recognized by white residue and foam formation under the oil filler cap.
• Oil escapes from the cylinder head, often together with cooling water.

Can you just keep going?

If there is a suspicion of a defect in the cylinder head or the cylinder head gasket, the vehicle should be can no longer be moved or at most to the workshop. With such a defect, engine damage is not far away. One danger is that the engine oil and the cooling water can mix. This mixing degrades the properties of the engine oil and jeopardizes the necessary lubrication. Engine damage occurs without lubrication. Since this also leads to a loss of cooling water, the engine can no longer be properly cooled and there is a risk of it overheating. Another reason for engine damage. Is there a risk of confusion? The damage could also block or on Crankcase instead of lying on the cylinder head. However, working on the cylinder head requires special expertise, accuracy and special tools. With this complex work, you should quickly refrain from trying to do it yourself. You can only find out by dismantling the cylinder head.

Topic: Main investigation

Whether the vehicle has a chance of passing the main inspection depends on the symptoms. A significant defect would be an oil leak with dripping. sweats If the engine only loses a little oil, it is not taken into account or it is only a minor defect, so the vehicle can pass the HU. The loss of cooling water or a failed emissions test are, however, a significant deficiency. A vehicle with a significant defect does not pass the general inspection.

Cylinder head/gasket repair/change

The important question is whether it just the gasket concerns or the cylinder head. This question can not be answered on a general basis. The symptoms can give good clues, but you don't know for sure until the cylinder head was dismantled. Only then can it be checked whether the leak is in the cylinder head and the gasket or perhaps even in the engine block itself. In many cases it is sufficient to replace the cylinder head gasket with a new part. Remanufactured cylinder heads are available as an option if that is the reason.

The repair process!

Depending on the structure of the engine, various parts must be removed, such as the Intake, the Injectors, elbow or the spark. The cooling water should be drained. The wheel of Camshaft must be freed from the toothed belt or timing chain. Is the cylinder head free, it can be dismantled. Now it is tested where the leak is exactly. Then it is determined which components need to be replaced. Depending on the diagnosis, any damaged components are replaced, such as the leaking cylinder head gasket. The valves, the valve stem seals, the piston rings, the pistons or the engine block itself may also have been damaged.

If the entire cylinder head is affected, it should be carefully considered whether the repair is still worthwhile or whether it is just one economic total loss acts. One must also consider that in any case the Cylinder head bolts need to be renewed. These are so-called expansion screws, which can only be used once. Is the damage to a so-called Water hammer, the same consideration is necessary. Cooling water/water then got into the combustion chamber. Usually the worst case scenario for the engine.

How expensive is work on the cylinder head?

The cost of repairs depends on where the cause lies. The effort involved in removing the cylinder head depends on the engine and the vehicle model. If only the seal is required for the repair, the costs for screws and a new seal are included 100 to 500 euros. In this case, Elring is a well-known manufacturer of spare parts. When replacing the entire cylinder head, however, costs quickly add up 500 to 3.000 euros at. Generally overhauled cylinder heads, on the other hand, are significantly cheaper. The time required for the work depends on the attachments, which also have to be removed. If the hourly wage of the workshop is 100 euros, the labor costs can be around 200 to 1.000 euros to lie. Add to that the cost of a new one oil filter and new Engine oil. Here the price depends on the amount of oil and types of oil and is enclosed 30 to 250 euros. The more special the type of oil, the more expensive it becomes. In addition there is something new cooling water. Depending on the engine, 3 to 5 liters of cooling water are required. A liter costs 5 to 10 euros, so a total of 15 to 50 euros. Roughly speaking, the calculation is between 900 and 5.000 euros.

Watch out: Some engines have two Cylinder banks, i.e. two cylinder heads and two cylinder head gaskets. Roughly speaking, the labor and material costs then double.

The cylinder head gasket: the importance and the wear!

The cylinder head gasket sits between the cylinder head and the engine block/crankcase and keeps everything tight. Different temperatures prevail in the cylinder head and in the engine block. The cylinder head gasket prevents tension due to the different thermal expansion. The cylinder head gasket is therefore a Wear part, since it is always exposed to chemical-physical processes. If there is a leak, engine oil and cooling water can mix or exhaust gases can get into the cooling water. The cylinder head gasket actually has a very long service life. In many cases, the life of the cylinder head gasket corresponds to the life of the vehicle. However, if the vehicle has a very high mileage, problems can arise as a result of overheating.

The following note is essential: For safety reasons, tuningblog recommends all repair, inspection and maintenance work exclusively to be carried out in a specialist workshop! Although our information is summarized to the best of our knowledge and belief, we cannot assume any liability for the content. All information is therefore "without guarantee".

Of course, that wasn't the end of it!

In this tuningblog category there are guides and instructions for common defects/repairs on the vehicle and for installing accessories/tuning parts. Our articles explain in a simple way common defects and the corresponding repairs, as well as explaining how the first signs of a defect become noticeable. In most cases, we also have initial clues to the repair instructions in our repair instructions approximate The costs of the pending repair are listed. The goal of our subcategory “Auto Repair Guide“ is to create a head start in knowledge for the next visit to the workshop with initial tips. This may save you from tedious troubleshooting and small things can perhaps be done directly on your own. The same applies, of course, to the installation of accessories/tuning parts. Here, too, we would like to help with the implementation with instructions and tips. There are many other posts on this as well. Below is an excerpt of the last and HERE there are all previous instructions:

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