Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 29
  1. #1
    GOT BOOST? Dockside's Avatar
    Join Date
    Dec 2008
    Location
    Ontario, Canada
    Posts
    3,879
    +1
    116

    Any HONDA mechanic's? NEED YOUR HELP!!!!

    I have a 2003 civic 1.7L vtec with some issues. Have 6 codes

    missfire code cylinder 1,2,3 & 4

    02 sensor

    Intake air sensor

    Now i just checked the fluids. oils good BUT coolant is a "very dark green" colour and it's way way to full for some reason and doesnt smell like coolant, is almost like carbon in it but not sure why its overfull car also when cold the rpms drop to 300 for a sec then revs to 2000-2500 the back to normal and does this a couple time till the car is warmed up.


  2. #2
    Quote Originally Posted by Dockside View Post
    I have a 2003 civic 1.7L vtec with some issues. Have 6 codes

    missfire code cylinder 1,2,3 & 4

    02 sensor

    Intake air sensor

    Now i just checked the fluids. oils good BUT coolant is a "very dark green" colour and it's way way to full for some reason and doesnt smell like coolant, is almost like carbon in it but not sure why its overfull car also when cold the rpms drop to 300 for a sec then revs to 2000-2500 the back to normal and does this a couple time till the car is warmed up.
    Well the missfire could be due to a lot of diffrent reasons. How many miles are on the car? when was the last time you had a valve adjustment? It unusual to see a missfire in all cylinders. First thing i would do is swap out for new plugs and make sure they are gapped properly. Plugs are usually the first thing to check when having a missfire, second would be valves and third would be timing. Depending which o2 sensor is throwing the code that could also be a reason for the missfire. most likley its the primary o2 sensor. when was the last time you had it changed. make sure that a squirl or some other animal did not chew threw the wires leading to the o2 under the car. I have seen it happen where a o2 went bad and that caused a missfire, when the o2 was replaced. missfire went away.

    The drop in the rpms is caused by your bad intake air sensor. especially while the car is cold and the ecu is running in open loop, the ecu is telling the injectors to dump more fuel while the intake air sensor is saying something diffrent. Does the car jerk when driving. is the car a 5-speed or auto? when the car is at proper operating temperature and you come to a stop, do the rpms drop then? Also on the easier side, make sure your air filter is not crazy dirty or cloged.

    Reguarding the coolant. does is fill thick or more like water? does the motor overheat? is there any dirt at the bottom of the resevour? smelling like carbon could mean a possible bad head gasket or a small puncture in the head gasket. it could be mixing with the exhaust. This one is easier to diagnose after you let us know if the car overheats while driving, or better yet standing in one spot? and do the radiator fans turn on? also if the fans do kick in, after one fan cycle carefully touch the top radiator hose going to the motor and see if its hot and does it feel like it has pressure inside, or can you easly push on it?

    Let me know some of the answer to the questions i asked. Im sure I can help you out.

    I build and race Honda's

  3. #3
    GOT BOOST? Dockside's Avatar
    Join Date
    Dec 2008
    Location
    Ontario, Canada
    Posts
    3,879
    +1
    116
    Quote Originally Posted by powerdbygarrett View Post
    Well the missfire could be due to a lot of diffrent reasons. How many miles are on the car? when was the last time you had a valve adjustment? It unusual to see a missfire in all cylinders. First thing i would do is swap out for new plugs and make sure they are gapped properly. Plugs are usually the first thing to check when having a missfire, second would be valves and third would be timing. Depending which o2 sensor is throwing the code that could also be a reason for the missfire. most likley its the primary o2 sensor. when was the last time you had it changed. make sure that a squirl or some other animal did not chew threw the wires leading to the o2 under the car. I have seen it happen where a o2 went bad and that caused a missfire, when the o2 was replaced. missfire went away.

    The drop in the rpms is caused by your bad intake air sensor. especially while the car is cold and the ecu is running in open loop, the ecu is telling the injectors to dump more fuel while the intake air sensor is saying something diffrent. Does the car jerk when driving. is the car a 5-speed or auto? when the car is at proper operating temperature and you come to a stop, do the rpms drop then? Also on the easier side, make sure your air filter is not crazy dirty or cloged.

    Reguarding the coolant. does is fill thick or more like water? does the motor overheat? is there any dirt at the bottom of the resevour? smelling like carbon could mean a possible bad head gasket or a small puncture in the head gasket. it could be mixing with the exhaust. This one is easier to diagnose after you let us know if the car overheats while driving, or better yet standing in one spot? and do the radiator fans turn on? also if the fans do kick in, after one fan cycle carefully touch the top radiator hose going to the motor and see if its hot and does it feel like it has pressure inside, or can you easly push on it?

    Let me know some of the answer to the questions i asked. Im sure I can help you out.

    I build and race Honda's
    just on my way to work. so gotta be quick lol...

    this is a on going problem the last year. intake air code is new though. Ive replace all the plugs and gaped them. 02 has never been changed. car has 180,000km's and it is not overheating and after 45 min of city driving coolant is still cool to the touch. once the car is warmed up it 100% fine. dont think its plugs or coils as the would cause all 4 to missfire.

  4. #4
    GOT BOOST? Dockside's Avatar
    Join Date
    Dec 2008
    Location
    Ontario, Canada
    Posts
    3,879
    +1
    116
    also like to note the coolant is full of what apears to be carbon this issue really has me stumped. what would cause a misfire on ALL 4 cylinders. Im thinking head gasket could be gone but cant see the afecting all 4 cyl

  5. #5
    Matthew K ReDevilRXP's Avatar
    Join Date
    Aug 2006
    Location
    Lemont, IL
    Posts
    2,477
    Is the coolant a really dark blue? Just to let you know Honda's coolant isnt the regular green or pink. they have a very unique Dark Blue color for their coolant.

    Checking the Intake air sensor is fairly easy. If the Pcm is setting a code for it, it means that there's a fault in the circuitry.

    I would check the wires to and from he IAT sensor and the iat sensor itself. Depending on the circuit if there is a open the pcm could be getting bad info thinking that's its super hot or cold outside. The bad info will play a major role in fuel delivery possibly causing a bad idle or hard start or even a misfire depending on temps. If i were you i would Tackle the IAT circuit and see if that all checks out good.

  6. #6
    Matthew K ReDevilRXP's Avatar
    Join Date
    Aug 2006
    Location
    Lemont, IL
    Posts
    2,477
    Here's a schematic for your car NON VTEC.

    looking at the schematic looks like the IAT wires and O2 sensor has a similar path. So you might have a electrical fault somewhere in that connector or something along those lines. Get that test light and DVOM out !
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	101605925.gif 
Views:	54 
Size:	39.5 KB 
ID:	178806  

  7. #7
    GOT BOOST? Dockside's Avatar
    Join Date
    Dec 2008
    Location
    Ontario, Canada
    Posts
    3,879
    +1
    116
    yes dark greenie blue but im concerned about the carbon like deposits in it and why it was cool to the touck after 45min of city driving the IAT code is new but i will check it. going to do a leak down test on saturday as i have a feeling it the head gasket.

  8. #8
    i'm a honda mechanic. Many of the 01-05 civic have headgasket problems. I've even fixed some with mileage as low as 75K. Honda kinda brushed this one under the rug, but if you google it you'll find thousnads of people with the same problem. At our shop we replace the entire engine assembly to avoid issues if there's a problem with the block of head (we've been faced with cracked blocks before). So unfortunately if you're smelling exhaust in the coolant then you're probably screwed.

    The O2 is probably just getting fouled out from burning coolant, and the coolant RESERVOIR is probably full because the exhaust gas is pushing the coolant in there. You need to check the radiator, it's probably very low.

    I'd ignore the IAT code for now, they rarely go. Reset the PCM and see if it comes back.

    I'd suggest saving up for some expensive repairs and keep nursing it along by adding coolant. Good luck.

  9. #9
    GOT BOOST? Dockside's Avatar
    Join Date
    Dec 2008
    Location
    Ontario, Canada
    Posts
    3,879
    +1
    116
    thats the thing im not going through any coolant if it needs a motor no big deal only take a couple hr to jam a new on in. but iv had these missfire codes for 2 years maybe more. It would only do this in the cold but now it constant. and it never throws the same MF code. 3 then 4 then 2cyl MF its very peratic. I had it at a friends shop he say the head gaskets fine.

  10. #10
    casey67's Avatar
    Join Date
    Sep 2006
    Location
    Lemont,IL
    Posts
    2,571
    +1
    35
    Does it actually missfire ?
    I'm not that familiar with Honda
    If it drops to 300 rpm,that's lower than expected,the PCM might see that as a missfire. the cars I'm used to,Ussually with an actual missfire below 3-400 rpm, should show a P0300=random missfire.

    Is the IAT clean ? Does your car have an oil coated air filter? ( K&N )

Page 1 of 3 1 2 3 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Any Honda Techs on here??? I need your help!!!
    By Dockside in forum Open Discussion
    Replies: 12
    Last Post: 02-08-2012, 12:47 PM
  2. Any Ford mechanics???? I need some help
    By Lvnspeed in forum Open Discussion
    Replies: 19
    Last Post: 02-03-2010, 04:28 PM
  3. RQ. I need your help over at petes again.
    By ccassone in forum Sea Doo Open Discussion
    Replies: 9
    Last Post: 06-08-2006, 10:20 PM
  4. Paging 96XPSS. I need your help over at snkypete's!
    By ccassone in forum Sea Doo Open Discussion
    Replies: 4
    Last Post: 04-25-2006, 06:42 PM
  5. OK Pine box derby experts - I need your help
    By Jeff C in forum Sea Doo Open Discussion
    Replies: 2
    Last Post: 11-16-2005, 04:03 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •