Runs cooler before dusting and adding a fan? WTF?

Color me confused...I just did a serious cleaning job on my case and hardware (ooohh...canned air...funnnn...) I cleared out a rediculous amount of dust and short of taking things apart (don't wanna do that right now...just don't wanna get into it) there probably isn't a single speck of dust left to get rid of. I also added a fourth 80 mm fan as an intake on the side. I ran my machine for awhile and the case temp didn't read below 35 and the CPU didn't read below about 56. Before I did all of this, I was getting case temps that would top out at 33 (and on average would be about 30) and CPU temps around 51. Even those are a bit high for a P4 that isn't overclocked, and I figured that cleaning out the dust in the heatsink fan and everywhere else would at least get me down in the 40s for a CPU temp. So I'm scratching my head here.

I tried turning around the fan on the side, so right now it's exhausting and MBM is showing me a case temp of 38 and a CPU temp of 58, though it hasn't been running as long as it had with it intaking. The temp seems to drop the longer it runs, and under load it doesn't (and never really has) changed much temp-wise.

Currently, my setup is thus: 2 80mm intakes in the front, 1 80mm exhausting on the side, and 1 80mm exhausting in the back. I have a Thermaltake Spark 7 heatsink on my processor that seems to be functioning properly. I've got rounded cables, and most of the extraeneous crap is crammed in an empty drive bay. Common sense would suggest that I should be running a bit cooler than this.

I have a couple of hypotheses as to changes I could make, though lazy person that I am, I don't want to get up to my elbows in computer again today unless someone else thinks that any of them might work. My first thought is that if I remember correctly I set up my heatsink fan on the auto control setting, which means that it may or may not be running at full speed. I could sacrifice a few decibels for that, I suppose.
My other thought is to reverse the airflow entirely and have intake in the back and the side and exhaust in the front. That one would be a little more work and I really don't want to start doing that and have it be a futile effort.

If anyone has any thoughts on this or any ideas that I haven't thought of (that don't involve hacking up my case...don't really feel like doing that right now either) shoot them my way. I'm just not terribly keen on the readings I'm getting all of a sudden.

 

First off, cleaning your PC is not going make it hotter.
Room temperature is big factor
Location of tower factor, dont locate near any heat source, monitors get hot so best place is not next to one.
Maybe time to remove CPU heatsink and apply some good thermal compond.
Case fans = is best to have incomming air at lower front of case and exausting air out upper back of case / slightly more air in than out.
Side mount fan in or out depends sometimes good to blow in, would help cool AGP card.
Sometimes a CPU fan that is too powerfull will disturb proper case airflow.
Make sure your powersupply fans are working, did you clean it too!

Maybe something here wiil help
http://www.overclockers.com/topiclist/index09.asp

 

Never said that cleaning it made it hotter, it just happened to be that the readings were hotter after I cleaned it, which made no sense.

Everything is set up as you mentioned. I've got good thermal compound between the CPU and the heatsink (Arctic Silver 4 comparable), and after I cleaned all of my fans, you could have done surgery with the fan blades they were so sterile

I'm inclined to think that possibly the heatsink just needs to be reseated, as it may have been jarred when I moved home from school. I might look into that as I honestly can't think of anything else.

Then I'll be on to my next project...reduction of vibration noise. Alas a tinkerer's work is never done.

 

.... ??
Get some AS 5 or some Ceramique on it.

 

Maybe you've created a vacuum by adding the 4th fan? So you now have less airflow than before.