After letting my engine idle for approx 5-10 minutes, it starts all of a sudden surging up and down between 1k and 2k rpm's. I have no vacuum leaks, and no other major problem. I USED to have a cracked head gasket, but I have taken care of that properly.

I took the oil cap off with the engine running and the engine surging, and white smoke was coming out of it and it smelled like exhaust. Whenever I revved up the car, the surging went away, but came right back after a little while.

I was thinking that maybe my cat was clogged or soemthing and caused a backup of exhaust gases and causes the engine to choke up and surge. Is this possible? When i had a cracked head gasket, water puored out of the exhaust manifold like a waterhose into the exhaust system. I think it clogged up the cat and what-not.

Anybody have any imput?

 

hook up a cheapo vacuum gauge to port vacuum on the intake manifold and watch the readings as you rev it to 2500. If the needle starts to drop you have a plugged cat.

 

bump n e one else?

 

anyboody else have an answer or input?

 

http://www.ef-honda.com/ben/Badidle.php

 

please tell me you bought new headbolts on that head gasket job?

 

you did check for warpage across the head and block surfaces? water makes streams...

 

one more, If It surges up and down and you did both of them look into your IAC. it may be clogged not getting the right cooling temp. or it got cooked when you overheated.

 

yes a machine shop took care of any warping there was. and no, i didnt get new head bolts. the machine shop said they werent needed.

 

the machine shop ran you a second head gasket, you choose door number 2.