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DEALINGDEALING WITHWITH OILOIL CONSUMPTIONCONSUMPTION ISSUESISSUES BBYY SSAMAM BBELLELL AA steadysteady drip,drip, drip,drip, dripdrip ofof oiloil oror internalinternal burningburning maymay bebe puttingputting thethe longevitylongevity ofof youryour customers’customers’ enginesengines atat risk.risk. TheThe causecause mustmust bebe identifiedidentified andand aa coursecourse ofof actionaction determined,determined, beforebefore expensiveexpensive damagedamage isis done.done. 20 March 2014 hen I was a little boy, our fami- down the road with an empty tranny. Ouch! Be- ly took annual driving trips to lieve it or not, we recently saw a replay of this visit my grandmother a couple with a Subaru, as well. of states away. Whenever we Then there was a Volvo 240 whose oil pressure stop ped for gas, Dad always sending unit had the misfortune to be cracked by asked the pump attendant to the same neophyte’s oil filter strap wrench. That check the oil. When I wondered one year why it car made it almost to the end of the block. Final- wouldW need to be checked so often, Dad hand- ly, topping off the lube shop’s first full week in op- ed me the Owner’s Manual and told me to read eration, the poor fellow failed to notice the stuck it. This ploy kept me quiet for many miles. oil filter O-ring on the brand-new Corvette (2760 When I had finished reading it, I was no miles!) when he installed the replacement filter. more enlightened than before, so I asked Dad The ’Vette got about three miles away before the for some elaboration. “Well,” he replied, “did “extra” gasket blew out. you find a schedule for oil leaks in there?” “No, sir.” 2 Engine Oil Gone M.I.A. “That’s why.” Lesson learned. This case involved a 2002 Corolla with the fa- VW and Audi recently declared that oil con- miliar 1ZZ-FE engine. The car was owned since sumption of up to a quart every 650 miles is new by an older gentleman who drove it only to “normal” on some of their vehicles, while Gen- and from his teaching job at a local university. eral Motors says consumption of up to a quart His wife did all the shopping in her own car, every 2000 miles is acceptable. Unfortunately, which they also used for all their social engage- the oil change minder system may wait to re- ments and family trips. Reaching retirement mind the driver it’s time for some basic mainte- age, he decided to relocate across the country to nance until well after all the lube is gone. the West Coast and sent his wife ahead. Clearly, those carmakers think such oil con- He brought his car to a local shop for an oil sumption is acceptable. Your customers may not change and a trip-check. The odometer at the agree, however. Indeed, judging by some of the time showed about 32,400 miles. Everything remarks posted on various online user forums, seemed to be shipshape. About a week later, he this may be the understatement of the year (see set off in his Corolla, fully loaded with stuff not “How Much Is Too Much?” on page 26)! previously moved. The first two and a half days A hundred years ago, most carmakers recom- of his trip passed uneventfully. mended that motor oil be changed at intervals of Then, somewhere in the Badlands of South 500 to 2000 miles. The addition of oil filters al- Dakota, the oil warning light came on, and the lowed 3000-mile oil changes. New advances in oil engine made a noise “like a threshing machine.” technology, filtration, PCV systems and engine Undeterred, the man pushed on until the en- management systems make substantially longer gine seized a mile or two later. He was towed to drain intervals possible, provided that someone the nearest Toyota dealership. When the drain occasionally checks the oil. Indeed, some manu- plug was removed, no appreciable oil came out, facturers now call for routine change intervals of although the oil filter was still full. Examination as long as two years or 30,000 miles. This does of the tailpipe showed some oily black sootlike not strike me as a safe idea, except where reliable deposits. on-board oil level and quality monitoring sensors I was hired as an expert witness after the man are installed. (Some 30-plus years of operating filed suit claiming that the local technician had my own shop have taught me that few, if any, cus- drained the oil but failed to replenish it. The tomers will reliably check under their hoods be- claim was obviously false, since he had by then tween recommended service intervals.) driven over 1900 miles before the failure, and The following case studies of oil consumption since the filter was full of clean-looking oil. But problems will give you some insight into how to the questions remained: What happened to that handle the issue on afflicted vehicles that arrive oil? Why would a car that had never used oil in at your shop. the past suddenly consume nearly four quarts in less than 2000 miles? 1 Oops, My Bad The answer lay in the sudden change of driv- Truth, it is said, is stranger than fiction. Some ing style. Here’s what I believe happened: years ago, a new fast-lube site opened near my During the man’s previous local driving, the shop, and its first week of operation was quite upper reaches of the cylinder walls had accumu- eventful. Mistaking the transmission’s oil drain lated a thin coating of varnish consisting of de- for the engine’s, a rookie lube tech then over- posits of unburned gasoline, condensed PCV gas- Photos: Thinkstock Photos: filled the Saab motor by four quarts and sent it es and other contaminants. These deposits were March 2014 21 DEALING WITH OIL CONSUMPTION ISSUES situated just above the upper piston ring, Additional varnish deposits then be- I find deposits on the oxygen sensors in the area “shadowed” by the top of the gan to accumulate as the top ring’s and in the tailpipe to be the most reli- piston. On his trip, the first time in tens scraping action became increasingly in- able marker. An upper-engine decar- of thousands of miles that his engine had effective. A small amount of varnish was bonization treatment often helps, been thoroughly warmed up, the upper then deposited on the upper surface of though it’s by no means a sure-fire cure. piston ring began to come into contact the second ring, leading to ever-increas- Still, it’s a valid first and maybe even with some of these deposits. (Remember ing oil consumption. (Toyota, to its second attempt, especially at a fraction that metal expands with heat, allowing credit, apparently anticipated such a sit- of the price of a ring job (see “Upper the relatively thin connecting rod to uation. In its Owner’s Manuals, it ad- Engine Decarbonization” on page 28). “stretch” just slightly relative to the monishes drivers to check the oil level This is one reason the 1950s fixation height of the cylinder wall.) As the ring at each refueling stop.) on low-mileage used cars is no longer entered the previously untraveled por- This case, like most, never went to appropriate. Give me a high-mileage tion of the top of the cylinder wall, it be- trial, and was settled by the local shop’s used car every time; it at least knows gan to scrape off the varnishlike deposits. insurance company whose analysis was how to go! Some of these gooey accumulations that a jury would likely ignore the facts landed on the top side of the upper ring. and concentrate on compensating the 3 A Lighter Shade of Pale With all due respect to Procol Harum, a puff of gray to blue smoke may be only the visual sign of certain types of oil consumption problems. Look for this on cold start-up. A brief puff of oily smoke that clears up almost immediate- ly often points to oil leakage down the valve guides. A new set of valve stem seals will often curb the vapors, though it may fail to treat the underlying prob- lem of worn valve guides. The geometry of modern overhead- cam engines acting directly on their fol- lowers positioned axially above their valves has reduced the incidence of un- even, ovaloid stem wear compared to its earlier endemic prevalence in rocker- valve motors. However, there are a number of rocker-valve engines still in Photos: Sam Bell Photos: The distributor block-off seal/plug (shown in place below the removed cap) production, so the issue is far from be- from this Camry was a leaker. The oil travels down below the coil bracket, ing a mere historical memory. reaches the level of the head gasket, then travels along to drip off the protrud- Off-axis forces exerted on the top of ing gasket edge at the back of the engine, mimicking a head gasket leak. Be sure the valve stem tend to force it perpendic- to order up a valve cover gasket and plug tube seals. Clean the cover and its ularly toward or away from the camshaft baffles, add on a new PCV valve and grommet and you’re good to go. as the valve moves vertically relative to the guide. Over time, the slightly softer Compounding the problem, the ring was “innocent” driver. Nevertheless, it raises metal of the guide wears toward an oval forced further than usual into its groove a very real question: If (and it’s a big if) shape.

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