Changed Coolant.. now Engine Revs up?

[Brad G.]

Hoping someone can help me out here! :(

 

Last night I drained the old coolant out of my 1999 Prelude (DOHC VTEC model, automatic 4-speed) and refilled the reservoir tank up to the MAX line with Prestone's extended life 50/50 premixed ("sillicate-free") engine coolant/antifreeze mix.

 

Now, when I start the car, the engine revs up to almost 2k RPM's then falls back down to its normal idle in rapid succession. I opened up the radiator cap and all I saw was a bunch of frothy bubbles.

 

Could this be because I didn't use genuine Honda coolant? How would I go about fixing this? Drain the system again and run distilled water through, drain again, and re-fill?

[lceah]

You have air bubbles in there.

 

The coolant type you used is fine.

 

I wouldn't put water in there.

 

To fix your problem:

 

1) You could open up another place to let the air out... (not too easy an option)

2) (best option in my opinion) Every day, open the cap and fill it with the same coolant...keep doing this until it's full

[Ben.]

I always just added and started/idled, added started/idled, so on and so forth until there were no bubbles rising to the top of the cap.

[Brad G.]

I finally got it resolved by opening up the bleeder nipple on the thermostat. It gurgled for a bit and then a steady flow of coolant came out.

 

Wiped off the coolant, topped off the radiator w/ some more fluid, then started and idled. Voila - after a few minutes, RPMs sank to 800 and sat at a steady idle.

 

<insert sigh of relief here>

[lceah]

^great!

[Velocifero]

I finally got it resolved by opening up the bleeder nipple on the thermostat. It gurgled for a bit and then a steady flow of coolant came out.

 

Wiped off the coolant, topped off the radiator w/ some more fluid, then started and idled. Voila - after a few minutes, RPMs sank to 800 and sat at a steady idle.

 

<insert sigh of relief here>

I was just going to suggest that, good work.