Mazda announces fix for CX-5 oil problem

words - Feann Torr
Owners of Mazda's CX-5 diesel to be offered engine software update and a new dipstick to solve oil overfilling issue

Mazda Australia has come up with a solution for the oil overfilling problem that has afflicted some versions of its CX-5 turbo-diesel.

As previously reported, Mazda had recommended that diesel CX-5 owners regularly check their oil levels, following up to 200 reports of oil "dilution" due to diesel fuel leaking into the oil sump after the vehicle was driven for short periods regularly.

The fix involves a replacement dipstick and a software change that modifies the operation of the diesel particulate filter, which was found to be the cause of the problem. Mazda said owners of affected vehicles will be advised of the remedy.

“We're able to confirm that the fix to rectify CX-5 models affected by oil dilution issues is now available,” Mazda Australia Public Relations Manager Steve Maciver told

“Along with a simple software update to modify the operation of the diesel particulate filter, a revised dipstick will also be fitted and the first supplies of these have now come into the country.

“Mazda has already begun contacting owners of affected vehicles to arrange to have the fix applied under normal warranty provisions,” said Mr Maciver.

The oil dilution issue was caused by diesel fuel moving into the diesel CX-5’s oil sump in some vehicles that regularly undertook short trips.

Brief running periods were found to prevent the diesel particulate filter from heating up and operating correctly, causing it to clog with soot prematurely.

To stop the filter clogging with soot, diesel fuel is discharged during the exhaust stroke of the engine to raise heat levels faster, but some fuel finds its way into the sump, where it combines with the oil and increases the level in the engine.

Mazda says the problem does not affect its brand-new Mazda6 sedan and wagon, which went on sale in December with the same 2.2-litre diesel engine.

Despite the recall, the Mazda CX-5 has been an unmitigated success for the Japanese importer in Australia since the vehicle launched here in March 2012, rocketing up the medium SUV charts.

It is currently the second most popular vehicle in its class with 14,355 sales to November this year and also took out top honours in's mid-sized SUV comparison.

The Nissan X-Trail is only a few hundred sales in front (15,007) and Australia’s top-selling SUV, Toyota’s large Prado off-roader, is slightly further ahead (15,732), but the CX-5 was unavailable here for the first two months of this year.

The addition of a 2.5-litre petrol-powered flagship next year could therefore make the CX-5 Australia’s most popular SUV and a top-ten selling vehicle overall in 2013.

The CX-5 will have to do battle with a number of new mid-size SUV releases next year, however, including the recently launched Honda CR-V and Mitsubishi Outlander, Subaru’s new Forester and Toyota’s new RAV4 (both due by February) and Ford’s redesigned Kuga SUV (due in the second quarter).

Published : Thursday, 20 December 2012
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