Head Gasket Replacement
Not every shop will actually do a Head Gasket Replacement
Head gasket replacement is a labor-intensive but necessary process when a vehicle’s head gasket fails. While there are some alternatives to temporarily repair a leaking head gasket, people who choose this route often face even more expensive repairs to other components from damage caused by using that type of product along with having to replace the failed head gasket that started the whole issue. The cost to replace a head gasket can multiply quickly if a cheap sealant job fails and causes damages to your engine block, engine bearings, cylinder head, radiator and more.
What does a head gasket do? Your car’s engine is divided into two main parts, the cylinder block where the pistons, connecting rods and crankshaft reside and the cylinder head where the valves, spark plugs and camshaft(s) are located. Cushioned between these two engine parts is the head gasket. This gasket can be multi layered metal or graphite composite in design. The head gasket’s job is multi-fold: to seal combustion chamber pressure that can reach in excess of 2000 pounds per square inch with extreme temperatures of nearly 3,000 degrees Fahrenheit during the power stork over 50 times a second and highway speeds. It also has to separate coolant passages that hold almost 20 pounds per square inch of pressure (with temperatures over 230 degrees) and engine oil passages that typically run 40-70 pounds per square inch. All this sealing must be achieved and maintained while withstanding the stress of the two surfaces expanding, shrinking and warping to a point.
Can you drive with a failed head gasket?
The answer depends on lots of variables, the type of engine and how the gasket fails. Generally is advised to not drive the vehicle if you believe your head gasket has failed. You could cause significant damage that could quickly turn a head gasket replacement into an engine replacement.
The Cost of Head Gasket Repair The price of head gasket replacement or repair can vary between different mechanic shops for many reasons. Each head gasket replacement is a little bit different. Nobody can tell you exactly what your car will need until the engine has been disassembled and inspected. That said, anybody who has done a few will have a pretty good idea what the vehicle is likely to need. An experienced honest mechanic will give you a minimum realistic price before starting the work. A questionable shop will give you the minimum possible price, even though they know that your car will almost certainly need more than what they included in the quote. When calling repair shops for price quotes, be aware that....
No matter what the quote, expect it to go up, at least a little bit. We aim for “minimum realistic”. We include the things that are usually needed based on our experience with other head gasket repairs. However, we don’t have a crystal ball, and we won’t know that the head is damaged beyond repair, or one of the rods is bent, or if the deck surface is unacceptable due to cylinder liner lifting until we take it apart.
Price quotes will differ greatly in several important areas:
Services included – Removing all required components to remove the cylinder head and replace the head gasket (obviously). Disassembly of the cylinder head. This isn’t necessary to replace the gasket, but it is necessary to clean all cylinder head components, inspect head casting(s) for cracks, check valve guide/stem wear, and inspect valve seat condition. Many vehicles have 100k miles or more by the time a head gasket replacement is needed resulting in a fair amount of wear on the valve train components. Aluminum OHC heads should be checked for flatness in two places: across the face of the head with a straight edge, and down the OHC cam bores. Straightening if required and resurfacing the cylinder head, with the wide use of MLS head gaskets by many auto manufactures surface finish requirements (Ra) and flatness play a big role in sealing ability of the head gasket. Many shops do not include rebuilding the cylinder head(s) in the initial quote. At 5 Star Auto Care we always include this. Our in house machine shop allows us to provide this service on every head gasket job we do to restore the cylinder head(s) to like new condition before installation.
Parts replaced - Head gasket repair usually involves replacing other maintenance items and needed or damaged components as well; ask what parts the price includes.
The Quality of parts used - Using high-quality parts is extremely important. You will not save money in the long run by opting for cheaper parts. Low-quality parts can cause damage to many other engine components and often result in having to have the same repair done twice. We use high-quality parts and do the job right the first time.
Warranty provided - The warranty will depend on the quality of parts and the confidence the repair shop has in the skill and expertise of their mechanics. Always ask if the warranty includes parts and labor.
Final thoughts - Hopefully I’ve answered some of your questions about this type of repair, but reading an article is no substitute for communicating with your mechanic. With large projects it’s very important that everybody is on the same page. Take your time to ask questions about the required repair and make a considered decision.