Yeah its normal.
The lack of air flow will mean the cooling system has to work that much harder to keep up.
If your on a air cooled cpu I would recommend going for the H60 AIO solution.
Swap the fans out for Corsair ML120Pro on the radiator for less noise but same performance.
These do not give bios errors if you plug them on the right header.
For intake I recommend removing the HDD cage to install a fan in its place. Sticky Velcro works if you want a easy to remove fan.
The normal intake fan can be replaced without any real issues.
Run a Y splitter off your fan headers to allow for 2x intake fans and 2 fans on push pull for the radiator.
Set a manual fan curve of 80%
I set my pump at 100%.
In this configuration you are at least giving the GPU half a chance to breath.
But this is just my opinion.
I do not work for Dell