2 problems: disaperring antifreeze & rough idling

I'd hate to break this too you, but if you're both smelling burnt up antifreeze and loosing it at the same time. I'd definitely take a look at the exhaust. Start the motor and let it idle. Watch the exhaust for either water, or steam / whitish smoke. If you're seeing a lot of vapor after the engine is warmed up you're loosing anti-freeze into the engine itself. Most likely due to a blown head gasket or could be as bad as a cracked head (which the windstars were pretty good for), or even the chance of a cracked block.

If it was me, I'd take the van to a good mechanic and have them do a pressure test on the cooling system. If it's loosing pressure then it's definitely a problem. One major overheat can cause a blown head gasket or worse. So, definitely find the cause and problem there.

Also, as for the OBD reading a lean on bank 1, it could be from the O2 sensors reading water vapors in the exaust. It could be clouding a reading and causing such a problem.

Personally, as I've said, I'd run it to a good mechanic who can pressure test your cooling system. It definitely sounds like you have a blown head gasket to me. It could possibly be a cracked head, but more likely towards the gasket. Do the small test I told you with the exhaust. Let it idle and check the exhaust, then even hit the throttle and see if it shows then. If you're smelling anti-freeze out the tailpipe, it's definitely not a good sign.

(Water of course will cause this rough idle as well. It will hurt the combustion process and give you the rough idling.)

I hope this helps, and I hope it's not a major problem. But, I'd definitely find out if it's leaking water into the motor.

Put a cooling system pressure tester on the radiator, do not start the engine when you do this test. pump it up to about 18PSI and look for leaks, Fix any you find and retest. If you see no leaks just leave it on there and keep it pumped up to around 18PSI or more and look for any leakage at all. If none Take out all the spark plugs and leave the cooling pressure tester on. Somehow look into the cylinders and look for evidence of coolant which will indicate a bad headgasket or cracked head.

I don't think a compression test will reveal cracks, also a CHEMICAL BLOCK TEST may reveal a headgasket or similar problem but only maybe very hit and miss, depending on the severity of the problem.

NO! not a fuel pump thats why he works there and is not a technician.Several things could be goin on there.
A vacuum leak at the intake manifold on that bank.
A plugged or defective fuel injector (remember the key word here is lean ,lack of fuel)
A fuel injector that is not being pulsed by the PCM (computer)
Coolant leak into a cylinder on that bank diluting the air/fuel mixture
A bad 02 sensor giving a "false lean" message to the PCM
A code reader is NOT a scan tool You need a professional Diagnostic Technician to check your car out sure it may cost you $200. or more but at least you will know exactly what is wrong and not just a wild guess, with YOUR money.
Please let me know if I can help in anyway but here in Fixya not too many people can help you other that give you false hope Im being honest
The most accurate way of finding a stubborn vacuum leak is a SMOKE MACHINE we have to use them here in Seattle because of this is an Emissions state and Smoke machines are a very important part of an accurate drivability diagnostics to make cars pass emissions failures.
Please send any feedback to [email protected] Thank You,Randy