Without seeing your recipe it's impossible to know if you are using too much oil or not.
I think your problem is one of three things.
1. You're not running your recipe through a calculator before making it therefore the percentage could be off and you could be super fatting it too much and causing the extra oil that does not react to the lye to ooze out. You need to ALWAYS run a batch through a calculator before making it for the first time no matter where you get your recipe from. Here is one calculator you can use: http://www.soapcalc.com/calc/SoapCalc.asp
2. You are overheating your soap. This can cause a "volcano" reaction. In that case you need to either soap at a lower temp or you need to review how to do the CPOP method and make sure that you're not getting your heat too high in the oven.
3. You're not melting down your oils before mixing with your lye solution. Your coconut oil should already be melted down to a liquid form when you mix it with your lye solution so there should not be any further melting after that.
If you're brand new to this you may want to try making a one oil soap first to get the hang of the process before continuing with the three oils. Olive makes a nice (some people find it slimey but it's great after a long cure) soap by itself.