Oil residue above the alternator on 2021 CX-5

[iccu]

Hello everyone, I am new here.

I own a 2021 Mazda CX5 with about 50k miles. There is a black residue above the alternator.

At first glance, it looks like oil though I am not sure if it is coming from the belt tensioner or timing chain cover. (I could not see any visible oil spots under the engine bay..)

Has anyone else dealt with this type of issue on CX-5?
- What issues do you think this might be related to?

Any insight would be very helpful. Thank you!

 

[MazdaCX5_GT]

I have the same thing… noticed today… did you ever find out what was going on?

 

[Jmaz]

Looks like rubber residue from belt wear. Check the serpentine belt for excessive wear. Rub some between your fingers to see if it feels oily. Wipe /wash it off and see if it returns.

I own a 2021 Mazda CX5 with about 50k miles. There is a black residue above the alternator.

At first glance, it looks like oil though I am not sure if it is coming from the belt tensioner or timing chain cover. (I could not see any visible oil spots under the engine bay..)

Has anyone else dealt with this type of issue on CX-5?
- What issues do you think this might be related to?

Any insight would be very helpful. Thank you!

View attachment 344130
View attachment 344131

 

[clownshoes2]

I was told that the belt tensioner is leaking, that's why it's there.

 

[Jmaz]

I was told that the belt tensioner is leaking, that's why it's there.

Yes, I think you are correct, and having had a leaking tensioner that was the first thing I thought of also but I didn't see deposit on the body thinking it was just shadow but do see it now. I would have expected more leakage down the side and front. The mileage at 50K fits right in also since it's apparently been leaking for some time and when my CX-5 experienced this the dealer told me they generally leak around 40K miles. Judging from the angle of the photo it still seems like the oil has migrated pretty far considering it's thick consistency.

 

[ColoradoDriver]

Possible, but when my belt tensioner was leaking, the actual tensioner was covered in a black film and yours appears to be completely fine?

That said, I agree mileage is about right for the thing to leak, so seems plausible. If you take it to someone or DIY it, I'd just replace the belt while you are at it too.

 

[bdc101]

This is just a teensy bit of oil leaking from the hydraulic tensioner, to which dust sticks to.

I am not sure about the CX-5s but my Mazda6 had a TSB with an updated tensioner. However, when I put the updated tensioner on, it still leaks a little bit.

It doesn't seem to affect the performance of the tensioner, at least as far as I can tell.