Good Morning all,

Hoping to get some help with an issue on our Diesel Mazda CX-5 - 2013 - 100k miles, I am going to ply you with a lot of information here so hopefully someone Mazda genius out there might be able to help.

Whilst driving at around 40-50 MPH the car started stuttering in low revs, almost like a misfire, ran a bit smoother when revved higher but began smoking, clear/white smoke. Car was immediately stopped and recovered via breakdown. The Breakdown Engineer plugged it in and said it looked like number 3 Injector was misfiring. We had it recovered to a local garage and replaced the injector and coded as required. This did not resolve the issue, had a few different Engineers plug it in with varying recommendations so decided to take it to the wonderful Mazda Hendy dealer in the Horsham as they advised over the phone their deep analysis would be able to find the fault and ensure it could be fixed. This would cost £130, higher than most but thought the extra charge was worth it to resolve the issue. They reported the below:

"the Technician has investigated as much as he possibly can whilst your vehicle is in the condition it is in.At the moment the Technician has confirmed he found a fault code (P2262) in the vehicles PCM (Power Control Module). This fault code indicated that there was a fault within the Turbo of your vehicle. Upon investigating your vehicles Turbo, the Technician found movement within the small turbine as well as oil within the Turbo itself. This is the main issue at hand at this current time as it means the Technician isn’t able to investigate further. This is due to not being able to run the engine for long enough or rev the engine due to possibly causing further engine damage.

In order to move forward with the investigation the Technician would need to replace the Turbo which would enable the vehicle to run and to stop the engine from causing any further internal damage.

Once the Turbo has been replaced the Technician would then have to carry out further investigation to see what caused the Turbo to fail and what the contributors were. The technician would begin that by carrying out oil pressure checks. That would then determine what to do next. If those oil pressure checks do fail the Technician would have to then investigate as to why they have failed. The technician has explained from experience, the oil strainer can be blocked with carbon. This would then mean the Technician would have to replace the oil strainer as well as carry out a full carbon clean of your engine.

Carbon can stick on the valves which can cause them to stay open which in turn can wear the camshaft. That would then mean your camshaft may also need replacing.

This is the full initial investigation report. Please let me know how you would like to proceed."

Now I am not massively clued up on cars but this didn't really seem like an issue with the turbo and when I investigated the error code it suggests it can sometime be to do with a sensor in the exhaust which would make sense as it was smoking a lot when we tested it out after replacing the injector. As Hendy quoted nearly £3k to replace the turbo and have advised this may not resolve the issue we opted to have a second opinion. He did a bit of a once over based on what they said, see below:

"Regarding my checks to confirm the turbo diagnosis. I have removed the intake pipe for the turbo and the engine breather. My findings were different from Mazda. I did find a very small amount of old residual oil in the breather pipe attached to the first turbo intake (Twin turbo) but none coming from the turbo, in my opinion it is completely normal and has come from the breather as you would expect to find when the crank case pressure is vented to the intake. The turbo itself has no signs of failed seals causing it to consume oil. There was zero end float or lateral play and the impellers spin freely. I have attached a photo, in my opinion this looks healthy. I have not inspected the other turbo.

I have been told to drop the down pipe, there should be some sort of reeve valve or some sort that is riveted on. The rivets have been known to fail and for the valve to drop down loose. I have checked the vacuum lines and can see no fault there. I have not checked the actuator as I did not have my vacuum pump to hand. I have also not tested the boost control module as I do not have the diagnostic equipment. It is not uncommon to see smoke when you have a misfire, this was white and smelt of un-combusted fuel/air mixture.

There is a common fault mainly affecting the 2013 models or any starting with chassis number JMZKE. There was a manufactures defect causing the impeller shafts to snap but you would definitely know if that had happened. I was unable to check if the recall had been done on yours, the online service was not working and Hendy was not answering the phone.

We have replaced and coded injector 3 and the fuel filter. I would suggest a second opinion as I do not trust Mazda’s diagnosis. The car does not struggle to start from hot or cold. I have not seen or smelt any blue smoke indicating oil but it clearly misfires under load whilst driving. The coolant is low in the expansion bottle and is dirty so could do with a flush but no signs of oil, head gasket or anything pointing towards the cause.

I have not checked the timing but I would imagine the crank and cam sensors would pick this up if it had jumped a tooth, assuming it has a sensor for both camshafts.

I also do not buy into Mazda’s opinion that the valves are coated with too much carbon causing one or more of the valves to not completely close. Judging by injector 3 (I know the nozzles are self-cleaning to some extent) this was very clean and was removed without any trouble. If the engine was carboned up to the point it was causing pinging, knocking or carbon to stick to the valve seats I would of expected the injector to put up a bit of a fight or at least some other sensors to **** the bed further reinforcing a carbon build up.

Regarding them mentioning the oil pump strainer being blocked, I think that is a load of rubbish too. It clearly has oil pressure and even if the pump had failed it would not cause it to misfire unless the engine was way too hot, all of which would be very obvious.

In my opinion given Nichole was driving and it suddenly broke down tells me that unless it was a catastrophic turbo failure or the control module then this would of been a gradual turbo failure, you most likely would of noticed poor performance, bad MPG, some intermittent smoking and oil consumption gradually getting worse over time. All of this combined suggests to me to ignore Mazda’s diagnosis and get a PROFESSIONAL opinion."
So we passed all this info on to a garage that take on difficult problems with cars and they came back saying they had a similar thing with another Mazda and after ploughing over £5k into still didn't get it running right. Obviously we want to avoid doing this so I thought I would see if any bright sparks out there recognise this issue and could suggest anything?

Happy to provide anymore info if I can and appreciate any help you can give.

Cheers, Joe

 

These engine do suffer badly from carbon build up, both in the intake and oil system ( seen plenty ) The turbos do have issues. Have you tested the oil pressure? I've seen dozens of these engines fail from oil dilution and excessive wear.