Honda Civic / Del Sol (1992 - 2000) EG/EH/EJ/EK/EM1 Discussion

help! 1998 civic ex

 
Old 04-30-2019, 06:35 PM
  #1  
Trial User
Thread Starter
 
Join Date: Apr 2019
Posts: 4
Default help! 1998 civic ex

i recently bought a 98 ex and i drove perfect until about 50 miles after driving it, check engine light came on, started idling rough and when i tried to rev slowly it would go from 1500 to 2000 like a rev limiter. plugged the code reader and it showed a code for the iacv, replaced it, and reset the battery, after 50 miles of driving......same issue again. pissed me off because i had just spent 160 on the valve. did some research, cleaned the intake manifold checked wires, plugs fuses, everything, so i thought maybe it was the tps sensor, replaced it, reset the check engine code and same issue again after 50 miles, same code, iacv, checked vaccum leaks and im out of ideas, and now the last thing that might fix it is if i replace the ecu. if i replace the ecu, do i have to reprogram it? im stuck, i love this car and i have so many plans for it, but im stuck no with this issue, thanks for any advise
aygi21 is offline  
Old 04-30-2019, 06:40 PM
  #2  
Honda-Tech Member
 
chrysler kid's Avatar
 
Join Date: Nov 2003
Location: Plano, Texas, USA
Posts: 1,438
Default Re: help! 1998 civic ex

You probably have an air bubble in the coolant line where it connects to the idle air control valve. If the valve gets too hot or not hot enough, it doesnt allow the correct amount of air to enter the motor and the map sensor sees this incorrect air flow and makes the idle air control valve act all wonky until it triggers a check engine light


Burp the cooling system and report back
chrysler kid is online now  
Old 04-30-2019, 06:47 PM
  #3  
Trial User
Thread Starter
 
Join Date: Apr 2019
Posts: 4
Default Re: help! 1998 civic ex

thanks, im not sure if i bled the coolant correctly the first time, is there a certain way to do it? thanks for the info, ill research how to take the air out
aygi21 is offline  
Old 04-30-2019, 07:10 PM
  #4  
Honda-Tech Member
 
chrysler kid's Avatar
 
Join Date: Nov 2003
Location: Plano, Texas, USA
Posts: 1,438
Default Re: help! 1998 civic ex

https://honda-tech.com/forums/honda-...iator-3305287/


Originally Posted by EE_Chris View Post
I've never seen an OBD2 D-series with a bleeder bolt. If anything, old school GS-R's were the ones to have the bleeder bolt on the upper radiator hose fitting.

The OEM thermostat for the OBD2 D-series engine begins to open at ~180* and is fully open by ~195*. The radiator fan kicks on ~205*. Water boils at 212*.

Make sure you have the heater control set to full hot (so that coolant can circulate through the heater core) but make sure the fan is OFF (so that it's not trying to cool the coolant you're waiting around on to get hot).

Leave the radiator cap off. Helms says to "leave it loose". I can only guess this is to prevent coolant from spilling out while air bubbles are being purged. I just leave the funnel sticking out of the radiator neck.

Fill the system with coolant, start the car and refill as needed. Stand around and wait for the cooling fan to at least come on once. I've NEVER waited a second time. If after the cooling fan kicks on once and you still see air bubbles, then wait some more. But in general, you really don't even need to wait till the cooling fan kicks on. By that time, you're assured that the thermostat has fully opened - or was suppose to.

Believe it or not, there are people out there that will drain what they can from the system, refill it and then tighten the radiator cap up and call it "finished". It's those massive air bubbles that were never purged that cause problems with the hunting idle.

I just did the timing belt on my 00 Ex this past weekend, so the procedure is fresh in my mind.
chrysler kid is online now  
Old 04-30-2019, 07:27 PM
  #5  
Trial User
Thread Starter
 
Join Date: Apr 2019
Posts: 4
Default Re: help! 1998 civic ex

thanks alot, i will do this tomorrow and let you know if it worked, thank you for your time again
aygi21 is offline  
Old 04-30-2019, 07:34 PM
  #6  
Honda-Tech Member
 
chrysler kid's Avatar
 
Join Date: Nov 2003
Location: Plano, Texas, USA
Posts: 1,438
Default Re: help! 1998 civic ex

Originally Posted by aygi21 View Post
thanks alot, i will do this tomorrow and let you know if it worked, thank you for your time again
chrysler kid is online now  
Old 04-30-2019, 08:48 PM
  #7  
Honda-Tech Member
 
Freedo_Civegra's Avatar
 
Join Date: Jan 2018
Location: Mississippi
Posts: 1,116
Default Re: help! 1998 civic ex

Originally Posted by chrysler kid View Post
You probably have an air bubble in the coolant line where it connects to the idle air control valve. If the valve gets too hot or not hot enough, it doesnt allow the correct amount of air to enter the motor and the map sensor sees this incorrect air flow and makes the idle air control valve act all wonky until it triggers a check engine light


Burp the cooling system and report back
MAP sensors detect air flow?
Freedo_Civegra is offline  
Old 05-01-2019, 02:34 PM
  #8  
Trial User
Thread Starter
 
Join Date: Apr 2019
Posts: 4
Default Re: help! 1998 civic ex

tried burping the coolant and i think i have a bad head gasket, just kept bubbling
aygi21 is offline  
Old 05-01-2019, 04:12 PM
  #9  
Honda-Tech Member
 
chrysler kid's Avatar
 
Join Date: Nov 2003
Location: Plano, Texas, USA
Posts: 1,438
Default Re: help! 1998 civic ex

Originally Posted by Freedo_Civegra View Post
MAP sensors detect air flow?
You knew what I ment, even though I didnt say it how I should have
chrysler kid is online now  
Old 05-01-2019, 04:16 PM
  #10  
Honda-Tech Member
 
chrysler kid's Avatar
 
Join Date: Nov 2003
Location: Plano, Texas, USA
Posts: 1,438
Default Re: help! 1998 civic ex

  • Originally Posted by aygi21 View Post
    tried burping the coolant and i think i have a bad head gasket, just kept bubbling
Squeeze the hoses several times to help the process. Remember the heater needs to be on so coolant circulates everywhere. I dont think its a head gasket because you dont have any other symptoms. It might have just been hiding tons of air. Reset the check engine light and See if it made any difference

Bubbling could also mean there is leak in the cooling system as well.

If burping a second time doesnt help, the next step would be renting a cooling system pressure tester from autozone or oreilleys and pressurizing the system and watching and listening for leaks.
chrysler kid is online now  

Thread Tools
Search this Thread

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: