Big problem with my CX7. Spark plug Fouled. Help

[CX7 Driver]

When the temperature out side is less than 32 F then the car is very hard to drive. It will not accelerate, and it is bug down. I went to the dealer four times already and all they do is clean the plugs an tell me to drive longer distance. My wife drives the car every morning to work for about one and a half hours. So what can I do? Is it maybe that the car is running to rich? So is the ECU bad?

 

[mikey1981]

1. use the search tool for the forum, its great for finding related answers located on the top tool bar, and
2. the car hates cold weather, I dont think there is something necessarily wrong with your particular vehicle, its just once it goes under freezing, the mazda doesnt like it much.

By the way, have they told you how they clean the plugs? you can probably save a trip to the dealer and do it yourself. Hold the accelerator down while in park and keep it around 4k rpms, when the rpms drop, it means, that in the computers eyes, it has cleaned the "plugs" - thats what my dealer had told me. it cycles the carbon out of the engine.

hope that helps.

 

[SuperStretch18]

In cold weather, the denser air makes the engine run lean, triggering a fuel cut situation. Do a search for "fuel cut" and you will come up with a ton of threads from the MS3 & MS6 guys on how they are addressing this. Not sure how you feel about modding, but there options available. If not, then a trip to the dealer might be in order. Not sure if they have any tricks, but it is something that they should be aware about on all of the DISI vehicles...

 

[CX7 Driver]

Thanks for helping me. The dealer takes the plugs out and cleans them. So for me to take them out is hard especially in the cold weather. Is there a hotter burning spark plugs available for it?

 

[erhayes]

I would hope you are using a top tier fuel or at minimum a name brand fuel of 91 or higher octane. Off brand gas does not have the additive packages that keep the valves and combustion chamber clean. Something doesn't sound right if your drives are that long and your constantly getting spark plug fouling. I suspect poor fuel as the most probable cause. People in Alaska drive CX7s so the cold you experience is mild in comparison. Maybe a good experienced mechanic will chime in here. Ed

 

[UpNorth]

I suspect poor fuel as the most probable cause. People in Alaska drive CX7s so the cold you experience is mild in comparison.

I'll take the Alaska cue.

I'm using Chevron's 90 octane (the highest we can get here). Most of my drives are short and I have cold weather much of the year. With that, my CX-7 is still fun to drive and responsive. I do warm up the car and suffer especially crummy mileage in the winter, but I think that your problem goes beyond the mercury dropping below 32. (Though now I want to do a search on fuel cut too.)

Good luck.

 

[StickShiftCamry]

Never heard cold being a problem, same response in 100 F and 12 F. These are isolated problems people are having, the car doesn't "hate" the cold, its a new car and it drives like a new car, which means perfect except for factory programmed delayed electronic throttle.

 

[erhayes]

I seem to remember something about a valve in the intake manifold system that causes cold weather issues. Check for TSBs as one was put out about the valve. I can't believe a dealer would have overlooked this possibility though. If I remember the TSB or can find it I will report back. Ed

 

[erhayes]

CX7 Driver. The service Bulletin you need to find to address your problem is 01-010/07 which was last issued on 7/13/2007. The Bulletin refers to a "variable Swirl Valve" that sticks in cold weather. Keep me/us informed when the issue is resolved. Ed

 

[CX7 Driver]

thank you all .
This morning had the same problem. Rev the engine to 3000 rpm for about a minuets and the rpm went up to 4000 rpm and after that the car was ok. I kind used what mikey1981 recommended to clear up carbon. I think It still a issue with carbon buildup on the spark plugs. I all ways use good gas 94 bp.
The mechanic at the dealer did ask me if i use the car on short trips, but I don't, even if I did then I can't believe that Mazda would build a car that can not be used on short trips.

 

[justanothermp5]

do u use premium gas? if not maybe tahts the problem with the sluggish feeling

 

[erhayes]

You should not need to rev the engine frequently to get it to run smoothly. I really think you may have a sticking variable swirl valve. I gave you the TSB number which also describes poor cold running issues such as you are experiencing. You are correct that Mazda would not build a car with that kind of problem. Get the dealer to fix it correctly and just cleaning the spark plugs is not fixing it. Ed

 

[CX7 Driver]

Thanks erhayes for the service bulletin. I will go to the dealer next week just printed it out today.

 

[Mazda3]

The problem is the O2 sensor. Mazda Canada has finally traced the power loss problem to faulty O2 sensors. There hasn't been an official TSB released yet, but the local dealer is replacing the O2 sensor on anyone experiencing these type of problems on the DISI motors. It was a hard problem to diagnose because the problem usually only occurs periodically in some vehicles and for some reason never throws a code or triggers the check engine light. It now seems that 75% of the issues with the way the CX-7 runs can be traced back to this sensor. Have your dealer call the techline. If the US techline doesn't know about this then have them call the the Canadian techline.

 

[erhayes]

So now you have two good posibilities to have the dealer check on. Maybe Mazda3 will give you the phone # and name of the service technician who understands the O2 problem.

 

[Rick's CX-7]

By the way, have they told you how they clean the plugs? you can probably save a trip to the dealer and do it yourself. Hold the accelerator down while in park and keep it around 4k rpms, when the rpms drop, it means, that in the computers eyes, it has cleaned the "plugs" - thats what my dealer had told me. it cycles the carbon out of the engine.

hope that helps.

How does holding the RPMs at 4k until they drop clean out carbon from the spark plugs? I mean, how does this actually happen?

 

[CX7 Driver]

My understanding is that the spark plugs will reach their optimum temp. and the carbon build up will burn off.

 

[Rick's CX-7]

I did this today and it worked just as you guys said. I held 4k RPMs for about 1-2 mins and after that, the speed went down to idle despite my foot being on the gas. Once I let go and stepped on it again, it was back to normal. Did it work....did it clean out the carbon? Who knows!

Rick

 

[CX7 Driver]

Finely had enough and called Mazda USA costumer service. Talk to a guy that took a report, once the dealer that did all the service calls them back he will see what he can do for me. Will let you guys know what they say when they call me back.

 

[mikey1981]

I did this today and it worked just as you guys said. I held 4k RPMs for about 1-2 mins and after that, the speed went down to idle despite my foot being on the gas. Once I let go and stepped on it again, it was back to normal. Did it work....did it clean out the carbon? Who knows!

Rick

. i think the only reason the tech even told me that procedure was because they were sick of seeing my cx-7 every day. if it works, who really knows....could never tell on mine because i had a zillion other probs.