Tune Up Is It Really Needed
It is understandable that so many people are confused about this subject as most of the information available is contradictory. The information is contradictory because professionals are stating their opinion based on their most recent experience or car manufacturer advertising propaganda. Many have not taken the time to evaluate the situation from all sides including surveying their customer base or analyzing the data they possess.
Those car manufacturer advertising departments are simply doing their job trying to convince the public that their vehicles are better and cost less to maintain than their competitor. They promote the idea of lower maintenance cost and increased reliability by pointing to their recommended maintenance schedules. Those maintenance schedules are intended to be ‘guides’ not gospel and there are so many caveats the only way to achieve some of that schedule is using laboratory conditions.
Tune Up is about how to protect your investment (family vehicle) and prevent expenses that will either destroy the family budget or cause serious financial hardship by simply performing proper maintenance. Your auto is like many other things you use on a daily basis. Take for instance your shoes, every day that you wear them the soles lose a little from wear until eventually you have to replace the soles or buy new shoes. It is no different with the family vehicle. Many components wear a little all the time until they eventually fail.
As these components wear some people notice small performance changes or a slight increase in fuel consumption. They start thinking of ways to ‘fix the problem’ and are inundated every day with miracle products promising everything. They see an advertisement for “a mechanic in a can” product to fix their problem. Typically, it is some fuel or oil additive and they buy it hoping to make things better and last longer on the cheap. Unfortunately, there is no such thing as “a mechanic in a can” and those additives can cause more harm than good. Additives can and do serve a purpose, but they must be used in the right fashion and at the right time.
Let us look at two simple tune up items that have very similar construction and most everyone recognizes the names. Those items are the spark plugs and the Heated Oxygen Sensors (HO2S). Both of these are constructed using a ceramic and are subject to damage from deposits. These deposits come from sources such as fuel additives, crankcase vapors, engine oil, and fuel.
When these two items become ‘coated’ from these deposits they cease working properly. The spark plugs can misfire which can cause other damage including excessive fuel consumption and a loss of power. The HO2S can minimally fail enough to cause a slight enrichment of the mixture. Many times this slight enrichment does not exhibit any symptoms that could warn the operator until the sensor is so bad that it turns on the Malfunction Indicator Lamp (MIL). By the time, this happens there are lots more damage that may need corrected.
This slight enrichment of the mixture from deposits can be observed with a practiced eye looking at the PCM data stream with an OBD2 Scan Tool such as the 2X80S and a professional software program like ScanMaster ELM.
When General Motors was building single and two wire Oxygen Sensors, they saw so much of this deposit problem reported from their service departments that they had OTC build a special function into the OTC Monitor Scan Tools to clean the sensor. This function is still there in the software, but it will not work on many later models.
One of the biggest advertising falsities is the 100k mile spark plug change. That has cost many people including car manufacturer’s more money than almost any other advertising claim made. Ask any mechanic with experience on engines like the Ford 4.6L, 5.4L and 5.9L or the Mercedes 3.2l and 3.5l engines, how hard it is to get those plugs out after as little as 40k miles…not to mention that job at 100k miles.
If a mechanic is not careful on removing the spark plugs, he will break them off and the customer will blame him, when it was the carbon deposits and lack of timely maintenance that is to blame. That Mercedes 6 cylinder engine has 12 spark plugs and so much carbon builds on those plugs normally that trying to remove them without something like parts loosener is taking a huge chance of breaking a plug off or destroying a cylinder head.
Very few people even those that say they take care of their cars maintenance really do a proper job. Most skip things like replacing a PCV valve, or the fuel filter. Failing to replace a PCV valve when due or replacing it with the wrong one can increase the carbon build up in engines.
As a preventative maintenance, it would be wise to perform a baseline performance diagnostic scan and keep a record of it. Then once every 6 months perform it again and compare to catch any early signs of failure. This could be done very easily with a scan tool and software program. This small investment will pay for itself many times over. This would serve multiple purposes, the best of which would be to catch small items that can be fixed inexpensively compared to a major expense like a full set of Catalytic Converters.
A maintenance tune up on that Mercedes every 40k to 50k miles can easily cost $1000.00 or more, but that is cheap when compared to performing the service and adding the cost of a full set of catalytic converters or removing the cylinder heads to repair damage caused from lack of maintenance.
You are now an informed person and it is up to you whether or not you do a maintenance tune up to restore the performance properly or trust “a mechanic in a can” additive or accept the owners manual maintenance schedule as gospel.
Copyright © 2012 JD Durham
JD Durham is a World Class Technician, an Automotive Hall of Fame honoree with 45 years experience in the automotive service and repair industry and a staff writer at Straight Talk Automotive. You are encouraged to visit for more information on OBD2 Scan Tool, and OBD Bluetooth scan tool, also accept this invitation to join our FREE members only area and access great free resources.
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