Maybe someone out there can give me so advise. My 1991 toyota previa van has water in the oil.I know that means a blowen head gasket. But the van does not over heat,never blow any smoke and runs perfect. Just have to put water in it twice a week. I also to this day drive the van 75 miles a day and have no probloms. Is it possible that it is not the head gasket,is there any other way for water to get in the oil? Thank u for any advice u give.

Head, head gasket, maybe a cracked block. That's pretty much it. A bad head gasket doesn't always change the way a car will run so you can't go by that. If you're having to add coolant and you're getting it in the oil, there is a problem which will become much bigger if you don't get it taken care of. You will soon wind up washing the bearings and that will be the end of your engine.

You need to get it looked at before you ruin your engine.

I remember hearing about head problems on these. What comes to mind is the cylinder head coolant core plugs in the head below the valve cover.
Do you have the 2TZ-FE engine?
If the VC was removed, and then a system pressure checker put on it, it would show you the leak in no time.
Approximate diagnosis time doing this would be 1.5 hrs.
If I can research more I'll update this post.

Here's what I was thinking of.
Attachment 39273