How to replace spark plugs Mazda CX7 2.3L Turbo 2010

[Cournane]

I am wondering if anyone knows how to change the spark plugs in a CX7 2.3L Turbo 2010. After I remove the engine cover it looks like the intercooler needs to be removed. I am a little concerned about removing the intercooler and was wondering what was involved.

 

[erhayes]

The intercooler is an easy remove. First remove the main in/out hoses and then the bolts holding the intercooler. Lift straight uo and there the engine is in all its glory. Surprised you are changing plugs in a 2010 as the change interval is 75,000? miles. I have 61K on my original and it still runs like new. Ed

 

[Cournane]

So I only have 40,000 miles done, the manual says to change the plugs every 60,000. The reason I am looking to do this is my MPG has been dropping slowly over the last 10,000 miles. I was averaging 24.3 mpg, I am now down to 21.9. I have replaced the air filter and the tire pressure is ok. The next most logical move I would have thought was to look at the plugs. The car does not seem to be mis firing and drives really smoothly. I really only use the car to get to work and most of it is open road without traffic. Is there anything else you would suggest to look at other than hooking the car up to measure air/fuel mixture? It is not a fuel grade issue as it is a slow drop off in MPG over month and multiple fill ups are involved.

Getting back to the plug question are there any gaskets I need to replace or just pull the hoses out? When I install the plugs and re-attach the hoses do I need to bleed the coolant? If so whats the best way to bleed the system? thank you for your help

 

[Crazee D]

I'm gonna do ours too.

 

[erhayes]

Bleed coolent? The intercooler hoses are for air only. I think you need to get a look at a CX7 service manual for guidance. Spark plug misfiring will result in a CEL. Is your check engine light on, indicating a problem? Maybe the mileage loss is as simple as e10 gas vs straight gas or winter vs summer grade gas or a heavy foot?

 

[Cournane]

There are no engine lights on. It could be winter gas v summer gas, someone else said it could be te viscosity of the engine oil, it could be air/ fuel mixture.
Thanks for letting me know there is only air in the intercooler, I also thought they were liquid cooled, life just got alot easier.

 

[Zhos]

If you have not replaced the plugs yet, I recommend going with either NGK's, or MAZDA OEM (which are also NGK's, check the plug for NGK markings). I made a mistake of getting autolite iridiums, and the car was driving like crap and misfiring all the time.