Today I explored the Micra's HR12DDR engine a bit more. My aim was to see how I could access:
1. Air filter
2. Coil packs/spark plugs
As the engine bay is compact it’s a bit fiddly and Nissan seem to have gone with a odd design compared to in the past which made it a bit quirky when putting it back together!
Removal
1. To make life a little bit easier you can remove front trumpet, just simply twist and remove. Note the rubber bush highlighted in yellow. It’s just push in and pull out - nothing secures it in place other than a bit of rubber grip
2. There are 2 clips securing the airbox (red box).
3. The box should then pull away. What you will see when you take it off is 3 tabs which sit in 3 corresponding holes on the mounting part. You have to pull the top bit away then lift up. Keeping in mind the rubber mounts highlighted in yellow
And that’s it, air filter and coil packs are now fully visible to do whatever you want!
Refitting
Refitting was a PITA and requires a bit of force. Easiest way I did it was to guide the right hand side locating tab in first, and then push the top part in. If you take a look at the top you will see there is a bit sticking out which interferes stopping you making it an easy fit. The left hand side is the same, just requires a bit of manual persuasion. Keeping in mind again the rubber bushes!
Refitting the trumpet is again pop in and twists until it locks in place
Can’t find any official documentation regarding this, all it says in the owners manual is take it to a dealer!
Airbox notes:
Smallish air filter, but I suppose with the engine being forced induction you can get away with it more
MAF sensor quite exposed and easily damaged. Previous Nissans I have played with usually have a wire mesh, or a throttle plate in the way! It states in the owners manual *ONLY* to use dry type filters. So oiled K&N filters are a no no (saying that, it’s been a no no for a while really!)
Part of the airbox is actually not used and inside the removable part is a blanking plate which cuts off around 1/3rd of the airbox and it cuts off part of the air filter as well. This was evident when I inspected the air filter dirt side, the part with the blanking plate was much much cleaner than the other side. Maybe this is done to reduce noise, but I would have thought cutting this bit out may help it breath a little better.
1. Air filter
2. Coil packs/spark plugs
As the engine bay is compact it’s a bit fiddly and Nissan seem to have gone with a odd design compared to in the past which made it a bit quirky when putting it back together!
Removal
1. To make life a little bit easier you can remove front trumpet, just simply twist and remove. Note the rubber bush highlighted in yellow. It’s just push in and pull out - nothing secures it in place other than a bit of rubber grip
2. There are 2 clips securing the airbox (red box).
3. The box should then pull away. What you will see when you take it off is 3 tabs which sit in 3 corresponding holes on the mounting part. You have to pull the top bit away then lift up. Keeping in mind the rubber mounts highlighted in yellow
And that’s it, air filter and coil packs are now fully visible to do whatever you want!
Refitting
Refitting was a PITA and requires a bit of force. Easiest way I did it was to guide the right hand side locating tab in first, and then push the top part in. If you take a look at the top you will see there is a bit sticking out which interferes stopping you making it an easy fit. The left hand side is the same, just requires a bit of manual persuasion. Keeping in mind again the rubber bushes!
Refitting the trumpet is again pop in and twists until it locks in place
Can’t find any official documentation regarding this, all it says in the owners manual is take it to a dealer!
Airbox notes:
Smallish air filter, but I suppose with the engine being forced induction you can get away with it more
MAF sensor quite exposed and easily damaged. Previous Nissans I have played with usually have a wire mesh, or a throttle plate in the way! It states in the owners manual *ONLY* to use dry type filters. So oiled K&N filters are a no no (saying that, it’s been a no no for a while really!)
Part of the airbox is actually not used and inside the removable part is a blanking plate which cuts off around 1/3rd of the airbox and it cuts off part of the air filter as well. This was evident when I inspected the air filter dirt side, the part with the blanking plate was much much cleaner than the other side. Maybe this is done to reduce noise, but I would have thought cutting this bit out may help it breath a little better.
