February 14, 2013
Finally, have a mechanic check for signs of excessive oil in the intake system, which could be the result of a worn-out turbocharger or turbo seals. The turbocharger should last the life of the vehicle if the oil change schedule is adhered to, and if the seller let the engine ‘idle down’ a moment or two after hard driving. Other signs of a bad turbo include smoke from the exhaust pipes, particularly while the car is idling for a few minutes before driving. Start your test-drive and walkaround by starting the engine and inspecting for tailpipe smoke once operating temperature is reached, and BEFORE driving. Also, ensure the seller hasn’t pre-warmed the engine ahead of your arrival to conceal a smoke-related problem.
Direct Injection engines, like the one used in the Mazdaspeed6, are more and more proving to have issues with carbon and other gunk building up on the intake valves, since the fuel injector is mounted inside of the cylinder and unable to ‘clean’ deposits away from the intake tract. This has proven an issue for some Mazdaspeed6 owners. Cleaning of the valves is a bit tricky, but possible. Signs of trouble include lower-than-expected performance, as well as low readings in a compression test. One of the best ways to combat valve gunk buildup is to use a quality grade of gas and engine oil, and to use a ‘catch can’ installed into the engine’s PCV system, which collects the oily blow-by that otherwise colonizes the intake tract and burns onto the valves. Note that modification of the engine’s emissions control system, including the PCV system, might be illegal in your locale.
Other checks mainly centre around fluid leaks—particularly from the radiator area up front, and the transmission in the middle. With the car in the air on a mechanic’s hoist, these should be easy to spot.
Mazdaspeed6, 2006-2007. Click image to enlarge
A lengthy list of potential issues and their fixes is available here:
The Verdict: A healthy, non-modified Mazdaspeed6 should prove a fairly reliable way to access upscale, all-season motoring thrills affordably. Most of the issues that have surfaced with this model will be quickly apparent to an inspecting Mazda mechanic, and a pre-purchase inspection at a Mazda dealer is highly recommended. If the rear-end and turbocharger system check out, and the model you’re considering has had its maintenance schedule adhered to, you should be able to buy with relative confidence.