I have 92 previa with 240K miles. Everything works, has no problems. All of a sudden last week, with both A/C full blast, egnine coolant started to boil. I popped the hood later on. I could hear coolant boiling. I don't believe it was low. As always, the A/C was not very cold.

I replaced the engine coolant with new one. The van runs well. Only problem is the engine starts to get hot when both A/C running. Without the A/C on, van runs fine.

What should I check next? Do I need to replace the radiator cap?

hi i had the same problem with my old work van. what we found was the fan hub was on its way out and had to get it pinned or better still replace it. you can also try flushing the radiator and heater core free everything up so there is no blockages or anything coolant ect will flow better therefore keep the engine cooler. i hope this has helped you shouldnt need to replace the radiator cap but its not that expensive to do it.

I flushed the engine coolant. Also replace the raditaor cap. The van seems to be doing fine for now.

Was hasitant to take it to work, 80 miles round trip. But I feel more confident now. Will give it a try next week.

I had the freon replace in the van with R134. The A/C is not working that grate. Will have a look at it or will have someone check it out for me.