My van overheated, now won't start!

The Previa cooling system is a little sensitive to bleeding and perhaps getting air trapped in it. I can't figure out why after filling the cooling system after replacing the cooling system you initially had a leak that went away or cure itself. After a 35 mile drive an air lock should have shown up and caused over heating. When you say it now won't start after over heating, does it try to crank over but "locks up"? This could be a blown head gasket allowing coolant to enter the cylinder and cause hydraulic locking which is going to be bad! Charge the battery, fill the cooling system, open the heater valve to allow coolant flow through the heater core, remove the spark plugs ( a little difficult in a Previa) crank over the engine does coolant spurt out of the spark plug holes? If so its bad news blown head gasket. Put back in your spark plugs, the two things I would then do (having access to tools and test equipment) is to pressurize the cooling system and check for external cooling system leaks. If the pressure tester leaks down pressure but no external leak is found it may be a sign of an internal leak (probably head gasket). The next valid test to do is called a "block check" the engine is run the radiator/expansion tank cap is removed and a chemical in a test tube has gasses from the cooling system drawn through it looking for the presence of Carbon Monoxide. CO will only be present in the cooling system if combustion gasses leak into the cooling system from the combustion chamber (cracked head or blown head gasket. Presence of CO turns the chemical from blue to yellow or green. I hope you didn't kill your van.

The Priva van is not unlike many others. The first clue was that you should have taken care of the over heating problem when it first started. My answer is the same as the last that posted. In my oppinion the head gasket blew and when you ran her agian the compression was lost and she will not start. I also would just have it tested to the change of color as that will tell you for sure. No easy fix to this one. Good luck as nothing on that van is easy to repair.

After experiencing some overheating, I recently self drained & flushed my 1993 Previa's radiator and reservoir tank with interesting results. First, I removed the top plastic air duct intake cover. Then I removed the radiator reservoir tank. After unscrewing the bottom radiator drain plug to drain coolant, I ran a yard water hose (with on/off hand grip for control) from the top radiator inlet hole and flushed out the old coolant. The interesting part came when I completely cleaned and flushed the coolant reservoir tank with a the yard water hose. I noticed that one or two of the three inlet/outlet nozzles had been clogged with debris and/or coolant sealant. So I cleared the reservoir's thin nozzles with a Q-tip and thin ice pick or screwdriver. It appeared that the reservoir tank had been clogged which made the cooling system inefficient, especially during warm weather with the AC on. To flush out the old coolant from the engine, I ran the yard water hose from top radiator hose with the engine one for about 1 minute. Eventually I saw old water/coolant flush out from the hoses that connects to the reservoir tank (which had been removed.) After 45 minutes of draining, cleaning, flushing, I hooked everything back up and refilled the radiator with fresh coolant. Be careful when removing the hoses... the nozzles, nipples, or hose connection tips can easily be broken if the rubber hoses are pulled the wrong way. For now it seems the radiator is keeping cool. If your temperature needle is showing up hot past the middle mark, try flushing out the reservoir tank to make the cooling system more efficient. It may be clogged because 3 of the 4 holes are very small and can easily get clogged with old coolant, debris, dirt and/or sealant.