Any mechanical failure must be analysed by an expert technician. They have a wide experience of working with machines and one should not be under the impression that by doing certain DIY tasks on weekends you can gain enough skill to perform a procedure of this scale. However, if you have taken the decision to do this job yourself then read on to know more about the process.
In order to provide the necessary lubrication the engine oil must flow through the ports that are present in the engine block and cylinder head assembly. Through these very ports engine coolant is also made to flow in order to control the temperature.
To prevent the fluids from mixing up and the compression from seeping from one cylinder into another, the cylinder head gasket is cut in a way that each cylinder is sealed and so are the respective oil ports and coolants.
Remember: The coolant turns into a brown sludge when oil enters the cooling system in a malfunctioning cylinder head gasket. You can notice this when the radiator cap is pulled off or when you take out the oil filler cap. However, there are other factors too that can trigger this possibility and in this article you can find the possible reasons behind such occurrences.
‘Examine the engine block and cylinder head’
You should conduct a thorough examination of the mating surfaces of cylinder head and engine block to ensure that it is flat and uniform which is extremely crucial to maintaining a perfect seal.
Sending the cylinder head assembly to a machine shop will ensure that you get a professional cleaning and inspection. The technicians at a machine shop will advise you if a valve replacement is required. They will also give you instructions about the possible issues with the engine, things that you need to bring along and other such details of their services.
A good way to gauge the flatness of cylinder head and engine block mating surfaces is to use a machined straight edge. The necessary specifications and measurement limits can be found in the vehicle service manual. The mating surfaces of the cylinder head and engine block must be perfectly flat and straight throughout. If it is not this way then the component may have to be replaced.
The straight edge should be placed across the engine block deck. A simple test to see if the engine block needs servicing or not is to switch on the flashlight and flashing it onto one side. If you are able to see light by peeking between the straight edge tool and engine block then you need to service the engine block. It happens because the deck is not flat and uniform and light becomes visible between the spots that have warped.
Remember: The technicians at the machine shop are the best judge of whether a mating surface is as flat as it should be. It will incorrect to jump to the conclusion that head gasket needs to be replaced solely based on the above deduction. Hence it is advisable that you consult with a technician before going ahead with the procedure.
‘Clear out the engine block and cylinder head assembly’
The mating surfaces of the cylinder head assembly and engine block must be absolutely clean. The technicians at the machine shop, to which you take your cylinder head, will look after its servicing and cleaning.
If you intend to clean this component yourself then you shouldn’t forget to check the surface between the intake and exhaust manifold. If the head gasket has suffered extensive damage then there are high chances of the cylinder heads being harmed as well. However, it is not easy to fix this problem yourself as you will need special tools and the procedure is something not every DIYer can handle.
Remember: To clean these surfaces you should never make use of grinding wheel or revolving disc as they can cause erosion of the metal surface. Using such tools can cause small granules of metal to get deposited in corners where it can be difficult to remove them. If the dust falls around the pistons in the combustion chamber there are chances of scratches along the cylinder walls. Needless to say it is a process that needs to be handled with utmost care and for this reason we recommend getting this problem fixed at the hands of experts.
‘Examine other components during dismantling’
It is not every day that you open the engine and take out components. Thus this is the best time to examine the components taken out while replacing the head gasket. By doing this you will be aware of the wear and tear that other components have been through and this should help you to prevent trouble in the future.
Remember: During the removal process there is high possibility of damaging spark plugs, coolant, belts, ignition wire, engine coolant thermostat, worn pulleys, timing components and seal. Also you may not have the different tools and components that are required for a particular procedure as it varies according to the application. Due to these complications, you should let a technician handle the head gasket replacement procedure who can do it at affordable rates.
‘Clean the Threads’
The spiral grooves of fasteners and bolt holes are susceptible to dust collection and this can lead to building up of dust and rust which can affect their ability to fasten around. They can also result in inaccurate torque numbers which happens when the fastener get stuck on the dirt. You can take these fasteners and bolts to the nearest hardware store and get these replaced. Any dirt that has collected along the threads can be easily cleaned using a tap on the cylinder head bolt holes.
Remember: Engine blocks usually have studs that are installed in the block. After the cylinder head has been fixed on the studs, a cap nut is fitted. The manufacturers’ manual should contain details on how to handle the studs. The studs can need changing and replacement from time to time and the stud holes should be cleaned thoroughly.
If you have a doubt about anything mentioned then you should not hesitate to take assistance from a professional. It is easy to become stubborn during a DIY task and assume that you do not need any help, but in this process you may cause more damage than what already is.