Hi Deso, I wouldn't have thought that K-seal would cause oil pressure problems, as it is for coolant leaks.
Was the coolant leak coming out of engine, or mixing with the oil?
I have used it in my Astra, as i thought i had a leak causing oil to get into the coolant. Not head gasket problem, as oil is not getting contaminated. I have never had the low pressure light come on due to the k-seal.
Regards Andy