MacBook Pro Early 2008 Fan running while in standby The fans in my MBP (MacBook Pro4,1) continue to run after closing the MacBook.
This is not because of the CPU running under high power, it's also happening when the CPU has done nothing for about 15 minutes. The fan runs either for about 5 hours or as long as it takes the MacBooks battery to get empty.

Info:
- I'm running 10.9.2
- I have this problem for about 2 years
- I ran an Apple Hardware Test
- I resetted the SMC and the PRam
- I reinstalled the MacBook with the original reinstall DVD (OS X 10.5.2) and updated version-by-version (10.6 -> 10.7 -> 10.8 -> 10.9)
- I replaced the battery
And it's getting worse with the time (until now, it stopped after about 5-10 minutes, but since last December, it doesn't stop anymore)

Note: Some people might say this is a duplicate of this question, but it's different, as in my case, the fans won't stop.
It would make sense from my point of view to look for a certified Apple Service Provider or Apple Retail Store and ask them about replacing your Mac thermal grease. Chances are they offer this in a sort of "spring cleaning" program. Over time the thermal paste between your CPU and GPU and the heat sink dries up and doesn't do what it is suppose to do. This can happen but doesn't mean it is, sometimes the fans just get full of dust and need to be cleaned out. The important thing is just making sure the mac is getting good airflow and that its vents are several inches (6-8) away from anything that could be obstructing airflow.