Car Starts sometimes and somtimes not. Buzzing sound in engine then clicking

I have a 2014 CX 5. It's worked fine till a month ago where it didn't start sometimes. The battery apparently died and I replaced it. Still doesn't always start and when it doesn't there is always a buzzing sound coming from engine. Sometimes when buzzing sound stops, it will start. Last week came back from work, shut the car off and buzzing sound was on. Then it went off. Next morning is was miraculously back on without starting the engine and wouldn't starts. Removed the positive terminal and buzzing stopped then put terminal on and buzzing resumed and did not start. Couple of days ago came back from work, buzzing sound was on then turned off after a minute or so. Next morning was a loud clicking sound and the car would not start. Removed battery terminal clicking stopped. Put terminal back on and no clicking but buzzing instead and car would not start. Removed terminal. Later, put terminal back on, no buzzing and car started. Left terminal on overnight and car started this morning.

I am really frustrated. I've taken the car to the local shop, they said car computer needed to reset properly. Car worked for a while then did not start again. Took it to dealer, they said it was the fob battery and replaced it. Also did their system check which pointed to the fob battery. Didn't start again with new battery in both fob and car. The buzzing still is there and this clicking comes periodically and still didn't not start yesterday but it did today. It is driving me craze. Please help if anyone can. Thanks.

Take the car to a shop where they actually know how to diagnose things besides sticking in a code reader

Thanks for the advice. Now if I could only find that kind of shop.

I'd videotape both the buzzing and the clicking. Open the hood and try to see where each sound is coming from and videotape that as well. May give the Tech an idea of where to look. The clicking sounds like a starter/battery issue but since you've replaced the battery the issue may be deeper. Also, sometimes a new battery can be bad from the start. Good luck, I hate electrical issues!

When I turn my engine off, my CX-5 makes that buzzing sound (under the hood) for about 30 sec or so. I have never tried to start it while it is buzzing. I does sound like you have a starter solenoid making the clicking. Do you have push-button start? The computer will try to start the engine but if there is a problem with the starter solenoid you will not get it to start. Take it to a different dealer.

Check the main fuse on the battery multitap

I would probably check the grounds to starter and chasey since the battery and fob has been eliminated. Ed

Thanks for the input. I'll tell the dealers service guys what they should look for since, at this point, they don't seem to know much about this issue.

I had all kind of weird issues, battery drain, etc. Turns out the wire harness in the door was letting water in and some connectors in the door and behind the fuse box corroded causing warning lights, battery drain and the security system disabled to car. Mazda has a TSB on this. It's a quick check once they know where to look.

What's that noise?

My 2012 Mazda cx5 sports auto started a loud clicking noise when switched off. Flattens battery. Have to disconnect battery. When reconnected the problem disappeared for a while. Now returned. Battery tested and good. Anyone else experience this?

It sounds like a starter fault to me.

Bcdad182 said:

I had all kind of weird issues, battery drain, etc. Turns out the wire harness in the door was letting water in and some connectors in the door and behind the fuse box corroded causing warning lights, battery drain and the security system disabled to car. Mazda has a TSB on this. It's a quick check once they know where to look.

Click to expand...

This is exactly what happened to me just before Christmas. Went out one morning to start my suv and the brake pedal would not go down fully....buzzing sound....vehicle wouldn't start. I called CAA and they came to boost me (CAA guy tested my battery and said it was completely dead...but also told me that something must be draining the battery). I then drove it to the dealership and left it with them. They did a diagnostic and told me it was just the battery, which they replaced. I went back to the dealership the next day to pick up my suv....and wouldn't you know it, it wouldn't start again (in their lot). So, they tell me that something must be draining the (new) battery. I left it with them again for 2 more days while they ran a bunch more tests. They call me back after a couple days and tell me it was the wire harness of the front drivers door that had gotten wet and caused various shortages. As my suv was almost 1 year out of warranty, the service girl put through an AWA (after warranty adjustment)....and Mazda Canada covered the cost of the additional testing, labor, and new electrical harness (over $600).....but I paid for the new battery and the original diagnostics ($230). I was ok with that. That being said, it appears there is an issue with the wire harness causing shortages.

Bon Scott

Bon Scott said:

They call me back after a couple days and tell me it was the wire harness of the front drivers door that had gotten wet and caused various shortages. Bon Scott

Click to expand...

Do you know the source of the water entry? Was the rubber boot broken? Did it leak from somewhere in the door? Or was it more in the body forward of the door? I think it would be good to know so that people could check and keep an eye on things. I know I sure would! Thanks.