I have a 2016.5 Mazda cx-5 grand touring. I replaced my spark plugs last week and all went smooth. Car started up, idle fine, no lights. I drove it for 2 days than randomly started the car and saw the orange check engine light on. Car also idled rough when at a light.

I got home and after a little, took out the spark plugs to see if something happened but they looked ok.

My issue now is the first 2 spark plugs (from right to left), screw in about 2 turns by hand and just get stuck. No wrench or anything I did was able to get them to install again. The 3rd and 4th were fine and when I put the good ones into the one getting stuck, the good one as stuck also. When putting the one that wouldn’t spin into the first, it went fine into the others so I’m thinking the threads are f’d.

I think I over tightened them and when removing I messed it up more somehow. I’m at the point where I don’t know what to do as I can’t get car anywhere and there’s so much info that I don’t know where to begin.

I’m hoping there’s something I can do to allow the plugs to spin by hand but both spark plug 1 and 2 spin twice and just stop. If I try to use socket wrench I can tell there not going in perfectly straight I don’t think.

I originally used new one and even bought a second set but same thing. Spark plug hole 1 and 2 have same issue, 3 and 4 are fine.

I’m not great with cars but seemed straight forward… which now really messed me up trying to get to work and figure out what to do.

Any help would be really appreciated. Are there any pictures I could attached that would help someone diagnosis I have a bunch. I just don’t really know what to look for.

 

You can buy a tool to try and restore the thread but it takes some skill so my recomendation is have it towed to a reputable shop.

 

Would a back tap possibly work?

 

This is the type of tool I'm talking about but if you messed up trying to fit a plug your likely to destroy the thread and have to remove the head to fix it. The plugs are deep down and it's difficult to get any repair tool in there.
https://www.ebay.com.au/itm/38860042...Bk9SR6rBrcCgZg

 

I actually bought one but they sent a 12mm 11” one but I ordered 14mm. Waiting for replacement. I used the 12mm just to get idea of length and it seemed to be long enough but I could be mistaken.

 

"I’m not great with cars but seemed straight forward… which now really messed me up trying to get to work and figure out what to do".

You admittedly incorrectly installed the plugs.
Therefor it is very doubtful you will be able to use the "tool" correctly.
Bite the bullet so to speak, and have your vehicle taken to a shop or get a qualified person to do it.
Or you may find yourself requiring a costly repair.

 

Ok ty

 

So to add.. you have a few issues going on but the first have a qualified service shop fix you spark plug cylinder threads before you do damage that will require R &R of the complete cylinder head.

The tool pictured in the inexperienced hands can further damage a thread in the location of a head with deep spark plug access.

Continued to attempt to drive with the spark plug incorrectly installed can cause other effects that could be detrimental and may in the end be costly to service.

When the threads are repaired the ECU will need to be completely checked for all DTCs that occurred during your short drive to make sure that all the issues are corrected.

Your estimated labor is about 2.0 hours. 1.0 hour for the thread repair and 1.O hour for diagnostics.

 

At this point it most certainly sounds as if you've miss/cross threaded the plugs. If you have no experience fixing such things now would be a good time to stop messing around and get some experienced/professional help.

IF the threads are mangled, it's possible that some of the thread material is 'flaking' off and falling into the cylinders while you are installing and uninstalling the plugs, that's NOT a good thing. Pieces of metal threads inside the cylinders are definitely something to be avoided.

What you need to see what's going on is a borescope camera, such as this one.


I have that camera and it comes with a magnetic attachment that would be ideal to use if one needed to fish out pieces of metal from a cylinder. Just saying. But in your case, someone with some experience is going to have to take a look and if the threads are mangled, they're going to have to be fixed one way or another.