Water oooled CPU throttling under load

Hello everyone... heres my issue

I recently built a new rig and I decieded to put a kuhler 620 in it.
Temps are great but for some reason whenever I run prime95 with in 5-10 mins the cpu multipler drops down to x4 (955BE).. temps drop real quick then go right back up.

I was reading it might be the voltage regulators on the MB getting to hot but speed fan says the MB stays under 34C underload..

CnQ and C1E are off... I have a 955 BE btw

please help?

Is there a decent amount of airflow around the CPU block? See if it happens with extra fans blowing on it and the side panel off.

Well I mounted a fan to the top of my rig to test it, but it still is giving me this issue... I tryed reseting the cmos to see if that helped but no good so far... Im getting about 39C under load @1.4 3.2ghz

Actually fixxed it by mounting a fan directly above the mosefs, thx

Glad to see the problem is sorted! I am a bit surprised though, most cases deliver enough airflow around the area. What case do you have?