Mazda CX-7 - DPF and Timing Chain...is there a link

Honest John Back Room » Technical matters
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Fri 28 Feb 2014 11:03
Mazda CX-7 - DPF and Timing Chain...is there a link - samobp

Please can you help? I think my Local Mazda dealer is playing tricks on me. I have recently purchased a 10 plate which had only done 36,000 miles. The DPF warning light flashed up and I went to my local dealer immediately. I will say at this point I know very little about the technical matters! So my car was serviced, but the next day the DPF light and service reminder were now both flashing. My car was booked in for another diagnostics check, this one FOC. I just assumed that some sort of service switch had not been reset right. Now it appears that I need my Timing Chain replaced to fix the DPF light? I mentioned this to a local mechanic looking after my wife’s older car. He says it sounds odd, after some google searches we find out that the CX-7 has a known issue with Timing chains. 2007-2010 CX-7 VVT Noise and Timing Chain Noise Warranty Extension SSP87.

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Fri 28 Feb 2014 11:11
Mazda CX-7 - DPF and Timing Chain...is there a link - craig-pd130

How recently did you buy it, was it from a Mazda dealer, and does it have a full Mazda service history?

The car has two separate faults: the timing chain fault that you've found information about; and a seperate problem related to the diesel particulate filter (DPF).

The DPF is in the exhaust pipe, and traps the soot particles in the engine's exhaust fumes. When the amount of soot trapped in the filter reaches a certain level, the engine control computer does certain things to start burning off the soot, converting it to carbon dioxide and water vapour and clearing (known as 'regenerating') the DPF.

The main thing is injecting a little extra diesel fuel into the engine's cylinders. This extra fuel doesn't get burned in the cylinders, but instead is carried in the exhaust fumes to the DPF, where it ignites and starts burning the soot.

Mazda diesel engines have had problems with too much diesel being used to try and burn the soot in the DPF. This extra diesel fuel finds its way into the engine's lubricating oil, diluting the oil and reducing the effectiveness of the lubrication - in turn causing problems with engine wear, which could also affect the timing chain.

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Fri 28 Feb 2014 14:05
Mazda CX-7 - DPF and Timing Chain...is there a link - samobp

I did not buy the car from a mazda dealer, but it has mazda FSH. I was advised by the dealer I bought it off to keep up with the Mazda Dealer servicing.

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Fri 28 Feb 2014 15:29
Mazda CX-7 - DPF and Timing Chain...is there a link - craig-pd130

The timing chain warranty extension might apply to your vehicle then, probably worth checking as the car has Mazda FSH.

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