Is this a DIY fixable problem?

Yeah it is probably fixable with alot of work sounds like your headgasket is blown. That coolant loss is coming from gasket

Driveway fixable? Paid $900 for the van. Other than this issue the van is really good and helpful. Any estimates on how long for a DIY repair? Or estimate or average cost of DIY repair?

It's kind of hard to say. For me it takes me 2 hrs to do a head gasket on a 4 cylinder. 4 hrs on a 6 cylinder (2 cylinder heads). But the problem is you don't know if the head is cracked or warped. You'd probably have to send to a head shop they will charge approx $300 per head plus head gasket is $80-100. That would be $700/800. May take you 8- 10 hrs if your unsure.

You can check the cylinder head your self to see if it leaks by pouring water in head and see if it leaks pass valves and using a straight edge. But that's like a mission

Is it a DIY job? That all depends on the experience and mechanical aptitude of the DIYer. Also various tools will be needed. I would say this is NOT a good DIY job for the average DIYer.

Thanks bob. Have some basic tool set tools from harbor freight. Experience and aptitude is moderate. Have replaced AC compressors, cabin blower fans, and normal tires and brakes jobs. Have some mechanical experience from the military. Have a junkyard semi-close. Have more determination than money.

Yes Bob is right. This job is a little more harder and will take time patients and allot of cursing involved :) just make sure everything you take out is reinstalled in same place with correct torque setting. I normally use a cardboard and poke holes through to tie strap items or hold pushrods

If you do decide to tackle it, go to your local O'reilly Auto Parts or similar and buy a Hayes or Chilton repair manual. It will be about $25 well spent.

True or just buy the blue devil. That they guarantee 5 year. It costs $60. But you pull the thermostat out and reattach hose. Drain coolant and let car heat up and pour it in radiator. My car held up for 2 years and still running strong