My tourist visa has almost expired and I will be going home first. My plan is to go the Cambodia for a couple of days just before it expires (I want to see Angkor Wat) then go back to bangkok and fly home. Will that be a problem? I know about the 3 month rule but since I was here on a tourist visa isnt that different?

So, what is your question?

Your post is unclear as to what you want to know!

As long as you are from a country allowed visa exempt entry you will receive the normal 30 day permitted to stay on your return to Thailand. Be sure to have your outbound tickets with you as they are likely to be checked. Your visa entry of 60 days ends when you leave the country unless you buy a re-entry permit at 1,000 baht to keep it alive. But that would not be worthwhile in your case as the 30 day entry is free and having not used any you have up to 90 days possible.

The tourist visa does not count on the 90 day visa exempt entry amount.