What to Do About Excessive Oil Consumption in Your Car

A Temporary Series of Articles
For the next two weeks we will cover a series of articles on auto repair that focuses on repair advice from the staff of Haynes repair manuals. In this piece, we will learn what excessive oil consumption is, the causes of it, and what your options are toward taking care of the problem.

Buying A Used Car with An Oil-Burning Problem
One of the most common problems of buying a used car is discovering too late that it is a real oil-burner that went undetected before buying.

That was the message in a “Mark’s Tip” advice column from the Haynes’ manuals website in which the author points out that an oil-burning used car is difficult to detect while taking it out for a test drive before buying.

“This is something you can’t predict when test driving, and more often than not, cannot sense or smell any oil burning off. It’s a problem that seems to sneak up on your vehicle at the worst possible time. The previous owner of the car might not inform you of this…and now you’re stuck with a vehicle that reminds you of your old 2-stroke motorcycle,” warns the advice columnist.

What is Oil Consumption?
Oil consumption is when a vehicle is burning oil rather than leaving a telltale leak on your driveway or garage floor. A good indication of an oil consumption problem is when you see your low-oil pressure check engine light come on between regular oil change intervals. All cars burn oil to some degree, but should not be so much as to trigger a dash light warning under normal driving conditions and when oil changes are done every five thousand miles.

According to the “Mark’s Tip” advice column, “The generally accepted allowed amount ranges between 0.0052 quarts to 0.3170 quarts per 621 miles, or 0.05 dl to 3 dl per 1000 km. Although this metric varies depending on the manufacturer, exceeding this would likely render a need for checking oil consumption.”

Causes of Excessive Oil Consumption

Causes of your car consuming too much oil include:

• You have an older car that has higher limits of oil consumption from the factory.
• You’re using the wrong grade or a poor-quality oil.
• Worn head gasket.
• Worn piston rings.
• Worn valve guides.
• Worn seals or gaskets---commonly involving valve cover, spark plug or other oil passage seals near the exhaust manifold.

To DIY or Not to DIY…That is The Question
While you would expect an automotive repair manual business to always push more towards the side of “Yes, you should DIY,” the Haynes tips article does offer some sound advice. One of which is to seek help from a mechanic first to ensure you have a correct diagnosis toward the cause of excessive oil consumption and the recommended repair(s) before worrying too much about answering the “To DIY or Not to DIY” question.

Once you know with some certainty what the exact problem is and what needs to be done, you can then start factoring in:

• The cost of having the mechanic do the repairs.
• The time it will take him to do it i.e., how long your car will be unavailable.
• The time you calculate for yourself to do it---and then multiply that by three.
• The costs of parts and tools to complete the job.
• An honest assessment of your skill level for this kind of repair and/or the ease of accessibility of getting to the problem under the hood that will not risk making an even bigger problem for you.

An Example of the Cost of a Mechanic to Diagnose and Fix

According to the tips article, using a 2012 Toyota 4Runner V6 as a representative example of what it will cost to have a mechanic do the work for you, here are the numbers estimated:

• Cylinder compression test: $370 to $472
• Valve cover gasket replacement: $773 to $973
• Camshaft replacement (likely needs removal if accessing valves/guides): $2,319 to $2,616.
• Cylinder head gasket replacement: $4,852 to $5,863 (both sides)
• Piston rings/engine rebuild: $6000+

What to Do?
If you decide not to pay a mechanic for a diagnosis, you can turn to a Haynes repair manual on your model of vehicle and get some instruction on tests you can do yourself (such as the relatively simple engine cylinder compression testing) to narrow down the source of your oil-burning issues as recommended by the tips article. And this is not such a bad idea.

If anything, it will help you evaluate whether this is a repair job you should attempt. In addition, it will also provide you with some knowledge you will want to have on hand should you hire out the repair and want to ensure that you are getting the service you are paying for.

The tips article also makes another good point: You just might be better off simply topping off the oil as frequently as you need as a cheap solution to what could easily become a financial burden on a car that does not have the valuation to justify an expensive repair.

“If their engine performs well and doesn’t leak, and the only issue is that the engine devours a quart of 10W-30 every month---some find this as okay to deal with, rather than spending thousands of dollars on a problem that essentially only costs them an extra $10-$15/month,” states the article.

However, if you have reached a diagnosis yourself (or paid a mechanic for one) and decide to go “Damn the torpedoes, full steam ahead” on the DIY repair question, I would offer the following recommendations:

• Do not depend on any single repair manual to have all the info you need to do the job.

• Have a backup plan for a replacement set of wheels until the job is done.

• Make friends with a knowledgeable mechanic you can go to with questions because THERE WILL BE QUESTIONS!

• Search for YouTube videos where someone is demonstrating the same repair on your vehicle make and model.

• Continue to refill your car’s engine oil as you read, study, re-read and re-study everything you can about the repair until you feel comfortable with what you are about to do. In other words---until you start dreaming about the repair and can visualize each step without turning to the manual.

That said, good luck and have fun with it.

And finally…

For additional news related to DIY repairs, here are a few articles for your consideration:

• Oil Stop Leak Product Warning for Car Owners

• A Simple Test to Avoid an Oil Leak Scam on Your Toyota

Timothy Boyer is a Torque News automotive reporter based in Cincinnati. Experienced with early car restorations, he regularly restores older vehicles with engine modifications for improved performance. Follow Tim on Twitter at @TimBoyerWrites for daily new and used vehicle news.

COMING UP NEXT: Toyota Tacoma Common Problems

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