Lack Of Engine Power? Strange Rattle From The Engine?
There are several reasons a vehicle will lack power when trying to accelerate. Today however were going to talk about lifters and how they can contribute to a lack of power when they aren't working properly.There are some warning signs that can be indicators of a bad lifter such as a rattling or ticking noise, misfire condition, or a check engine light. The most common indicators of a bad lifter are abnormal noises coming from the engine compartment and or a check engine light.
So what does a lifter do?
Lifters work directly with what is called the camshaft. The camshaft is a long piece of metal with some raised up sections called lobes. As the camshaft rotates the lobes make contact with the lifter and pushes the lifter up or down depending on camshaft location. When a lifter is moving up and down the valves inside the cylinder head are opening and closing allowing air and fuel into the cylinder, exhaust gases to exit the cylinder, or allowing proper compression by closing the valves in the cylinder head. There are two lifters per cylinder, one for the intake system and one for the exhaust system. Usually when a lifter fails it will cause a loud clattering or rattling noise and a misfire condition which can turn on a check engine light.
How do you determine if a lifter has failed?
The most reliable test is called a compression test. To perform a compression test a special adapter is needed to be installed into the suspected cylinder where the spark plug threads into the head. A gauge is then used to measure the PSI that is being produced inside the cylinder. The engine is then turned over and the gauge will read the highest compression reading and hold it. Compression ranges vary depending on vehicle make but average compression ratings are between 100 PSI – 200 PSI. Typically, all cylinders are compression tested and recorded, a properly functioning engine will have no more than a 10% compression variation across the cylinders. During the compression test of our example vehicle, it had less than 25 PSI of compression indicating the valves inside the cylinder head are either damaged or a lifter has failed. At this point the cylinder head was removed and internal parts were inspected.
Cylinder Head Inspection
Once the cylinder head was removed, disassembled, and inspected a damaged lifter was found. These lifters are one solid piece and as you can see one of the lifters is in two pieces. Luckily there was no damage to the valves in the cylinder head so correction is as simple as installing a new lifter and then reassembling the vehicle. This type of repair is considered a major repair due to the removal of the cylinder head and it is crucial that all proper procedures are followed and proper tools are used to correctly seat the cylinder head to the engine block.
The Finest Repairs With Personal Care
At Dickerson Automotive we have state of the art equipment and use updated repair manuals to ensure proper installation of these vital parts. We take pride in our work and stand behind it with the best warranty in Utah county 3 years or 36,000 miles. The automotive industry is constantly changing, and our staff takes every training opportunity we can to offer you the best repair shop experience.