WTF surging idle?

We may earn a small commission from affiliate links and paid advertisements. Terms

projectxspeed

Senior Member
Ok so my 1995 Honda Civic Ex 5spd radiator fell to pieces. Luckly it was parked, so I had it towed home. I replaced the thermastat, radiator, hoses, and clamps. I filled it will about 3/4 of a gallon of coolant, and started the car. It ran fine for about a minute, and then the idle started to surge. It revs up to 2200 then falls to 1500 and repeats the process. Ok I lost, why would replacing the radiator cause a surging idle?

Can anyone give me a direction to look in?
 
The IAC or idle air control motor uses coolant to set its idle RPM and ur are going to make sure u let the car run and bleed the air from the coolant system in order get it to idle the correct way.
 
Back
Top