Rubber Flap Covering Holes on Radiator Shroud?

[skyhammer]

I was checking out the motor last night and noticed a 4x5 inch rubber flap on the left side of the radiator shroud. It is covering four square holes on the back side of the shroud, and is held on by two small clips.Anybody have any idea what this is all about?By the way one of the clips was off and the rubber flap was flopping in the breeze.

[jpf2500]

Is it the rubber piece that seems to be made of two pieces to the right of the radiator - facing the truck from front to back (I know you said left but i did not know which direction you were facing). It also has a couple of plastic screws that are supposed to hold the two pieces together. But mine was also flapping around and not attached in all places. I was wondering the exact same thing as you if this is what you are talking about.

[skyhammer]

It is on the left side of the radiator as you are facing the front of the truck. It is directly under the radiator hose that goes to the water pump.Mine is held on by two small clips and covers four square holes in the radiator. Only the top of the rubber flap has the clips the bottom is free to flap around.I am baffled as to what its purpose is, as it is so flimsly and ill secured.

[jpf2500]

We are talking about two separate things then - I will check the left side of mine to see if I have the same thing - maybe you can check the right side to see if you have the rubber pieceds I am talking about as well. Thanks

[Stitch]

You know, I noticed that flap last night before I read this post. I have the same flap secured on top but not on the bottom. Yup , just on the left side under the hose.

We have the battery,oil and trans dipsticks on that side and I forgot what else is attached to the engine down lower, A/C compressor,Alternator, PS pump ?.

My guess is - it provides airflow / cooling for something specific or just in general. When that engine compartment was laid out I would guess Nissan monitored the temps at various locations and decided that was necessary.

[skyhammer]

Stich; You could be right. It just seems odd that Nissan would design the radiator shroud with the 4 holes and then cover it up with a rubber flap that that could easily fall off. Seems as though putting the flap on was an afterthought or a quick fix to a design flaw?

[Big Platinum]

I saw those before, I'm pretty sure they are so when at speed cool air passes thru, but when idling and in traffic, they close up so the fan pulls the air in and hot air doesn't backflow out the radiator from the eninge compartment negating the cooling effect. It looks like Nissan put some real thought into this truck!