We bought this '96, 3.0, 149,200 miles, from a corner car lot just before Christmas to replace our '93. Price on the windshield was $1250, but the guy said he didn't really recommend anyone buying it yet as he had just gotten it in, and hadn't had time to check it out. It obviously needed some work - ran a little rough, side door hard to open, tires shot, etc. But he said if somebody offered x$$, he'd sell it as is. Thought about it over the weekend, found this forum and did some research. Went back and asked "how much as it sits." "$800 plus tax, title, license." Took a short test drive and bought it. Our original plan was to fix the 96, swap the tires, and keep the '93 for parts. Then we decided the '93 still runs too well to just park it, and gets better mpg than my '94 Explorer, so we plan to keep all 3 vehicles running.
1'st I changed plugs, wires, pcv valve. Smoothed out the engine. Then tried to flush the cooling system as radiator was full of brown gunk. Replaced lower hose. Fixed sliding door ( bent rod ), and other little things. Changed the tar, I mean oil. Wife anxious to drive it. I said not until we get tires. Got tires Friday, and I think we're set. But no. After about 10 minutes driving, it pukes the coolant out. Refill, repeat. Several times. It's ok idling, but after a short drive, it loses the coolant. Today I put a new radiator and thermostat in it, knowing they're gunked up. I'm working on it at my workplace, about 3 miles from home. Filled it with just water, just in case. Let it idle a while. No leaks. Head for home. 1st 2 miles, it's looking good. Temp gauge between O and R, warm air. Suddenly, I felt cool air, temp gauge dropped to cold, and it puked the coolant again. ANY IDEAS? I don't know what else to do.
I could not have repaired most of what I have so far without this forum. Never would have figured out the door, changing plugs, etc, on my own. Bought this van because my wife likes the '93, and we could afford it. Less rust, and fewer miles. So far, we've got about $1400 (?) in it. Not bad if it was ready to drive, and still less than we would have had to pay for something else. $$$ is limited, but if we get this figured out, we should have a good van for several years. I need your help with this! THANK YOU!

 

Sorry for the long post. I typed it as 3 paragraphs, but it doesn't look that way!

 

What exacly do you mean by puked the coolant?

 

It dumps the coolant out through the overflow, like if it overheats, but it does it before it gets too hot. It overheats after it dumps the coolant.

 

Waterpump.
You (still) have minimal coolant circulation. Water starts to boil around the cylinders and will be pushed out through the overflow.

Check the drivebelt first.
If looks OK, replace the pump. Relatively easy, quick and cheap job.

 

I guess that would fit with it being ok at idle, but not at driving rpms. The belt is a Gates that looks pretty new. A waterpump is something I can handle, too, financially and mechanically! Thank you!

 

Now it all makes sense!
It did the same thing for its previous owner. He or she made the first step a.k.a. replaced the belt but then opted to dump the van instead of spending more money on a new pump. I have a feeling that you have replaced the rad and the t-stat unnecessarily. But look at the bright side: you have a new rad and t-stat and effectively your cooling system passed several pressure tests I can't wait to see the old pump. Pics please!

 

No, I didn't unnecessarily replace the radiator and t-stat. The radiator was full of brown gunk that never would have dissolved, and the t-stat didn't look the best either! I was hoping to avoid the expense, but it needed to be done. I've put some cleaner through it, but I still need to do a back flush. When I replaced the lower hose, the nipple on the front of the engine for the small hose was split. It got late and COLD, so I took the van back to work to get it inside. I don't have any water source there except the bathroom sink. Been too cold to do it at home for the last 3 weeks.

 

Ok, just so you don't get trapped in a money hole here, you want to get this fixed right the first time. Since you replaced the radiator, that was a good move in the right direction. Does your heater work properly? You can use whichever water pump you want, though I do recommend a good one like an AC Delco or Motorcraft. For the thermostat, I hope you used a Motorcraft, I have used a lot of aftermarket ones, only to find that you were lucky if they did work. The Motorcraft one is still an inexpensive part, but the quality is so much higher than anything else I've used. I have used generic, Napa Gold, Stant, Beck Arnley, Duralast, and I can remember the name of the other, just that it had Rad in the name. Also you can have the radiator cap tested. If it passes, good, if it fails, it can release pressure into the reservoir prematurely, resulting in overflow.

 

The heater works as long as there is enough coolant in the system, but as bad as the radiator looks, I wouldn't be surprised if the heater core looks the same. I'd rather wait til warm weather when I can change it outside at home if it will work well enough to get through this winter. I did not use a Motorcraft thermostat. If O'Reilly's would have had to order the radiator, I would have ordered a Motorcraft t-stat as well. The O'Reilly's warehouse is across the street from where I work and am working on the van. They actually had a radiator - which I think only fits Aerostars. The Motorcraft t-stat looks to be something even the warehouse doesn't stock, but they can get. I've never had an issue with t-stats going bad prematurely, and I keep my vehicles a long time. I've tried 3 radiator caps, all used, all the proper Motorcraft cap, and it has acted the same with all three.

I am a firm believer that God owns everything, and gives it to us to manage. As discouraging as this project has been, I think we were supposed to buy this van. This would have been a disaster for someone who needed the van to be ready and dependable from the day they bought it. Or for someone who had to pay for someone else to do the work. The car lot wouldn't have driven it long enough to find all the problems, and couldn't afford to pay his mechanic if he had. Even then the mechanic would have needed access to a resource like this forum to identify some of the problems and how to fix them - like the bent rod in the door, and the bad contacts on the sliding door.

 

Incorrect.
Overflow is created by boiling coolant arount the cylinders. Without that only a small amount of coolant will be pushed into the reservoir by thermal expansion.
A faulty cap would maintain lower/no pressure causing the coolant to start boiling at a lower temperature. However the cooling system is not supposed to reach that temperature anyway.
A lot more common issue is that when the whole system is cooling down a leaky cap would let the system suck in air instead of coolant back from the reservoir.

Either way it is not a critical problem and would not create any instant troubles.

I find this whole pressure vs boiling point very interesting. I used to work in a power plant where we had liquid water reaching 550 celsius due to 9MPa pressure. A few more MPa and we could have had glowing, red-hot water! How cool is that? (No pun intended)

 

I would replace the water pump first, most of the parts in the cooling system do not readily rust, the heads can. But most often the material comes from the impeller. The impeller is made from a sacrificial material, this is done deliberately to prevent the heads from rusting. So if you had lots of rust, it probably came from the impeller.

 

My guess is that "brown gunk" got (half)frozen and upon starting the engine the impeller broke off from the shaft or the blades got bent in a way that now they are not producing adequate coolant flow.

 

hopefully you don't have to worry about it, but the previous owner didn't change coolant for a long enough interval that my freeze plugs started to rust, and i had a lot of brown junk in my coolant. might be something to look at, depending on how long the car has been sitting.

 

The freeze plugs I can see look to be the brass ones. I have a busy week this week, and probably won't tackle the waterpump until next Thursday or Friday when I have a 4 day weekend.