Runs rough, backfiring when turned off and transmission makes a hum noise

Hi,

Did you use the correct type of transmission fluid? Some of these vehicles have a CVT transmission that requires specific fluid.

Also, how was the fluid level checked?

As far as the backfire, make sure the connections on the coil packs are tight.

Let me know if this has a CVT transmission and if you are confident the correct fluid was used. Also, here is a link that discusses common transmission issues. You may find it of interest.

https://www.2carpros.com/articles/automatic-transmission-problems

Take care,

Joe

Hi,

The spark plugs used in today's cars are iridium. They are usually good for about 100K miles. However, they too can fail.

If they had it in the air, that is how the transmission fluid level is checked. The vehicle has to be at operating temp, the transmission in park, and the engine running. Chances are that is why.

Do you presently have the vehicle? If you do, is the check engine light staying on when the vehicle is running? If it is, you really need to have the can bus scanned.

CAN stands for computer area network. Basically, all the computers/modules are tied together via a few wires. When you scan the Can-Bus, it will identify diagnostic trouble codes regardless of the module storing it. For example, if the ABS module or the transmission control module had codes, a basic scanner won't read them.

Here is a video showing it being done:

https://youtu.be/u-4syLc-ifQ

Let me know if you have questions or if there is something I can do to help. If you are able to have the computer scanned as I suggested, let me know what diagnostic trouble codes are found. Also, if you can record how the vehicle is running and upload it for me to hear, it may help me.

Take care,

Joe