1996 Tacoma LX Coolant Problem, Please Help

Coolant and misfire problems.
I’m fairly young, but I know I’ve got a gem of a truck. This thing hasn’t had but one problem and that was just the spark plugs causing misfires.
I recently had a problem one morning when I pulled out of my driveway the cab started shaking lightly and the check engine light flipped on.
Parked her back in the driveway and let her be till that afternoon. Buddy brought a code reader and it said misfire on cylinder 6 (same problem a couple years ago). We popped the hood and the coolant was completely empty even though we topped it off 3 weeks prior.
My dad and I did some general maintenance on her that same day 3 weeks ago: oil change, greased the drive shaft, ect. along with the coolant. I believe he fed water in it although I could be mistaken. A lot of people I’ve spoken to said it could be a head gasket leak. Some say the coolant could’ve leaked onto the plugs. I’m at a loss.
I would like suggestions on how to diagnose this myself. Military don’t pay me much so I’d like to save some change when I can too.

 

Its basically easy, if theres oil in coolant or coolant in your oil you have a bad head gasket.
If no leaks are visible and you are losing coolant most likely a head gasket. To verify can do a pressure leak down test on the engine cylinders. Also if you smell the exhaust and its sweet smelling also an indicator you prob have a head gasket leak.

 

If coolant is getting in the cylinder most times you have large amounts of white exhaust. That smells like coolant.

The downside is many times the heads can crack adding even more expense to a head gasket repair.

A coolant system pressure test can tell you if you have a loss of pressure.

good Luck!