My girlfriend's 2013 Mini developed this ticking issue when we were on a road trip a few weeks ago. Prior to this, I had topped off the oil with a synthetic blend 5w30, because the convenience store we were at did not have full synthetic. I do not see how the oil would make that much of a difference, and I am thinking it may have been a coincidence that the noise started soon after. The oil has since been changed back to full synthetic. Any ideas? Thanks in advance.

A couple of videos of it running:

Idling Video
Revving Video

 

The ticking of the injectors does not sound abnormally high (at least not in the videos and compared to my 2010 with the same N16 engine).

Instead, there seems to be a slight, low frequency rattling noise (not to be confused with the higher frequency "death rattle" noise indicating timing chain malfunction) that reminds me of the rattling friction wheel assembly my car developed:

Irrespective of that you should check your serpentine belt (both inner and outer surfaces) as well as the water pump pulley for possible wear and/or damage.

PS.: How cold was the engine prior to firing it up in the "revving" video? The idle revs seem rather high, even higher than what mine revs at while the engine is below 20 degrees C.

 

So it appears it is the friction wheel assembly. I did the exact same thing as in your video and the noise stopped. So it seems I need to replace that. The belt is also really cracked, so that will need replacing as well. Wonder if I should do the water pump & pulley while I'm down there... Thanks for your help.

 

It is very unlikely that the friction wheel assembly is the root cause. Change the serpentine belt first. If the rattling doesn't disappear, use a thin flat head screwdriver to thoroughly clean the tracks of the crank pulley.

Don't make the mistake I did: thinking that since the noise comes from the friction wheel assembly, it is the friction wheel assembly that needs to be replaced.

 

PS.: Replacing the water pump and its pulley is way (!) more work than just replacing the serpentine belt and (if necessary) cleaning the crank pulley. Also, getting to the serpentine belt in the future is no big deal at all. So unless there are any issues with the water pump and its pulley, I wouldn't touch them at this time.

 

PS. 2: Don't try to remove the crank pulley to clean it and more importantly: do not touch the bolt at its centre under any circumstances!

 

Noted thanks for the info!

 

@APOS I had the same noise as above, and changed out my water pump pulley, got the part from amazon (all the part stores wanted to sell the entire pump). This can be done via the wheel well (At least on my N14s) it wasn't easy or fun, but can be done with patiance, sure beats going in through the top of the engine... took about 90minutes to do, as its all by feel.

Good thing to check, is your water pump pulley for damage, as the friction wheel is metal it wears out the rubber on the water pump pulley, I had a tick/knock and swapped that pulley and poof all fixed!

 

Don't dig into the water pump if you do not need to. It is a bigger job than you may think. In my opinion, to do it correctly, I would do the pump, water pipe (under the intake to the t-stat), the t-stat housing and t-stat, related hoses. Most seem to go around 10 years and 100K or so. You may have a few years left in it. If your crank seal and / or crank pull go, then you might as well dig into all of it then. For now, I would hopefully just replace the belt and clean the pulley.

 

the pully on the water pump can be replaced without removing the pump, so release strain on the tensioner (between harmonic balancer pully and water pump pulley) Visually inspect the Water pump pulley, if there are pieces missing, or looks deformed, replace that. I found this was easy to confirm just starting the engine and listening through the passenger wheel well, and when i popped the tire off and the liner it was Clear that this was my issue. like i said, took 90mins to swap the pulley, and 100$, and of course a few curse words for tight areas to work from. If needed i will post a picture of my water pump pulley now that its removed to show what i mean by "bits missing" but i think that will explain it enough.

You can also check water pump pulley, by releasing the friction tensioner, have someone start car, listen at wheel well... Ticking gone? if so, its your pulley (or pump) if its there, time to look at timing chain.

To do the job of pulley swap.
Remove passenger Tire,
Remove fender Liner (or fold back)
Release Tensioner
get 2 12mm box head wrenches swivel head if you have em!
Work the nuts using 1 wrench on each to hold the pulley from spinning while breaking them free, of course do not remove them all the way until all 3 are broken free.
Remove pulley. (getting it out is the hard part, I had to work mine towards back of engine then drop down through the subframe)
Reverse the process, getting the pulley in is worse then getting it out.
Reset Tensioner,
Start car, Visually inspect to ensure rotation. Listen.
Reinstall fender liner
Reinstall Tire.

Have an ice cold beverage, (non alcholic) Test drive, ensure no high temp warnings... come home have a better ice cold beverage!