Sins done to my syncro

so I got an issue with my newly acquired vanagon syncro, 1986 a fine year I think I was five. Well this van has 235k on the odometer and seemed to be doing fine with a rebuilt engine just about 27k miles ago. Well the problem all began with bringing my better half parent to the airport in anchorage. the van did fine all the way to the pizza joint, but we found ourselves a forty five minute wait when we arrived so me, my better halfs dad and my son are all in the car waiting for the table. well my son in order to stay sane was pushing buttons left and right and without me noticing pulled out my rear differential lock. well lets just say i didn’t notice until, about half way home to girdwood with a more than upset child in the back seat. So I notice the button is pulled out and as quickly as possible I pull over and disengage the button. Now I don’t think that I have the accuator in place right now so I wasn’t too alarmed till I got home and radiator fluid was shooting out of the overflow holes in the res tank. So I immediately thought I had destroyed my vehicle. However I started to think i had overfilled my coolant and now it self corrected, well I got into the van today turned on the heating element in the front and back of the car and gave it a test drive down the highway about 10 miles, well when I arrived at my destination I was alarmed to see the color of my coolant had changed color. I am not sure if I have a leak in my head gasket or a leak in my coolant system, what do you fine gentlemen think that it could be. Also can your answer be easy and inexpensive to fix I need the van next week to move we are being asked to move out of our house so it can be sold and my van was going to do all of the moving

Please use paragraphs and caps for the first word of each sentence along with a space before each sentence.  Frankly I just could not read your message.

What color did the coolant change from and to? The reason I ask is because fresh coolant is no longer just green. There is yellow, red, and orange coolant being used today. If it went from green to brown, you have oil mixing with the coolant. This can be from a blown head gasket or other expensive mechanical damage. If it went from green to red, there is transmission fluid getting into the coolant, most likely from a leaking transmission cooler in the radiator. You’ll need to replace the radiator to fix it.

I doubt the diff lock did this. The diff lock does just that, locks the axles in the differential together. This makes it difficult to turn corners, since the axles are not allowed to turn at different speeds. You’ll feel it when one of the wheels binds up and causes a jump.

well the color turned from green to almost brownish color the heads had been rebuilt 25k ago, but maybe it is leaking. What about using the heating system could a leak in the lines cause discoloration and boiling? If it is my head how long can I drive it, I would assume not at all.

I wouldn’t drive it. Expensive damage only gets more expensive when you do. There is no other way for motor oil to get into the coolant than through the engine. The heater system has nothing to do with it.

More importantly, is coolant getting into the oil? Check the dipstick. If it looks milky, coolant is mixing with the oil. Emulsified oil has no lubricating properties, and this goop will destroy the bearings.