mhessick 07-06-2008, 07:46 PM 2000 EX 4wd auto, 77k miles - religious oil changes / maintenance.
Rough idle and CEL intermittant blinking / solid. No strange sounds from the motor.
Already replaced plugs with stock NGK's gapped at .044 w/ proper torque
Wires, Distributor Cap, and rotor replaced (and done right 1-3-2-4 )
Description :
The CEL light usually comes on and blinks right at start up. Once the motor warms up a little while, it stays on solid - but it's intermittant between blinking and solid.
When going up a hill at about 3000 rpm, it will go solid again.
Idles pretty rough with AC on, I'd estimate about 350-450.
From what I can gather, perhaps the distributor itself is going out, or there's something up with the timing.
Ideas?
the CEL codes are :
P0301
Cylinder 1 misfire
P0302
Cylinder 2 misfire
P0300
Random / Multiple cylinder misfire
P1399 (honda specific)
I appreciate any help - I'm fairly handy and knowledgable.
Black Pearl 07-06-2008, 08:16 PM Sorry to hear about your troubles. I am not one of the illumanati, but here are couple things that have been flying about forum recently.
Throttle body and air valve. Search for threads on that. Also there is valve adjustment. We do have some folks here that can help you out, I just am not one them but that will get you started until the Honda intellectuals come to your aid.
Welcome to the club and good luck with your problem.
tsmithvt 07-06-2008, 09:44 PM With those symptoms, work already done and current codes, it begins to sound like a classic tight valves issue.:( There is a lot of information available on the forum by searching "tight valves", "valve adjustment", "B20 valves", "burned valves" or something similar.
This link might be helpful if you decide a valve adjustment is required: CRV Rear Differencial (http://home.earthlink.net/~michaelpkeefe/HowTo_ValveAdj.htm)
Don't be concerned about the link title.
rberman999 07-07-2008, 08:57 AM mhessick,
Adjust your valves right away. I had the same codes in the past, valve adjustment clears them up. Lots of luck, Russ
Honda Tech 07-08-2008, 01:55 PM Wires, Distributor Cap, and rotor replaced (and done right 1-3-2-4 )
Isn't the firing order 1-3-4-2?
jeprox 07-08-2008, 02:46 PM sorry - just a side question...
first time i heard of tight valves issue - would too tight valves cause engine ping/knock? reason i ask is coz a honda mechanic told me tight valves may cause pinging/knocking.
Honda Tech 07-08-2008, 06:33 PM sorry - just a side question...
first time i heard of tight valves issue - would too tight valves cause engine ping/knock? reason i ask is coz a honda mechanic told me tight valves may cause pinging/knocking.
Pinging / knocking occurs when multiple flame fronts occur as the mixture in the combustion chamber is burning (as opposed to 'detonation' where the mixture within the cylinder violently and destructively "explodes"). The flame fronts collide and create an abrupt and uneven pressure pulse, generating the noise commonly referred to as "pinging" or "spark knock".
Causes range from high combustion temperatures / pressures (numerous issues can contibute to this) to insufficient octane rating of the gasoline being used. Pre-ignition (the mixture begins to burn prior to the timed spark ignition event) can also be a contributing factor.
"Tight" valves refers to the clearance (lash) between the rocker arms and the tips of the valve stems, or between the cam followers and the cam lobes depending on the configuration of a specific engine.
Lash clearances are checked "cold" on Hondas - the valve temperature must be less than 100 degrees F when the valve clearances are being checked.
As the valve train absorbs heat energy from the combustion process, the clearances will diminish due to thermal expansion.
If the clearances are insufficient cold, the lash will disappear when the engine reaches operating temperature.
Having no lash will result in the valve being physically prevented from fully closing.
Valves need to be able to close fully against their seats. Obviously a valve that could not fully close would result in compression loss and reduced combustion efficiency.
Not so obvious is that a valve that cannot fully close cannot transfer heat energy efficiently to the valve seat within the head (and into the cooling system where the energy can be dissipated).
Exhaust valves will get so hot that they can "burn" - the metal on the valve face melts and oxidizes.
Compression loss and reduced combustion efficiency can and will result in misfire DTCs and noticable degredation in engine performance and running quality.
Once it gets to the point where the valve has "burned", the cylinder will become "cold" - it is no longer capable of achieving the conditions necessary for combustion to occur.
So, to answer your question: theoretically, a valve that is getting super-heated to the point of "burning" could create pre-ignition and knock, at least until it burns away sufficiently that combustion is no longer occuring within that cylinder.
Since Hondas have been equipped for many years with knock sensors, the PCM / ECM will be adjusting the timing in response to the knock sensor signal, and the odds are better that you'd get misfire DTCs and an illuminated MIL before you noticed any knocking / pinging due to tight valves.
As an aside to the OP, (if you bothered to slog through this little novella) when the MIL is "flashing" that is informing you that the rate of misfire being detected is sufficient to cause damage to the catalytic convertor. Your issue can get pretty expensive pretty quick if you don't get it resolved soon.
jeprox 07-08-2008, 06:45 PM Pinging / knocking occurs when multiple flame fronts occur as the mixture in the combustion chamber is burning (as opposed to 'detonation' where the mixture within the cylinder violently and destructively "explodes"). The flame fronts collide and create an abrupt and uneven pressure pulse, generating the noise commonly referred to as "pinging" or "spark knock".
Causes range from high combustion temperatures / pressures (numerous issues can contibute to this) to insufficient octane rating of the gasoline being used. Pre-ignition (the mixture begins to burn prior to the timed spark ignition event) can also be a contributing factor.
"Tight" valves refers to the clearance (lash) between the rocker arms and the tips of the valve stems, or between the cam followers and the cam lobes depending on the configuration of a specific engine.
Lash clearances are checked "cold" on Hondas - the valve temperature must be less than 100 degrees F when the valve clearances are being checked.
As the valve train absorbs heat energy from the combustion process, the clearances will diminish due to thermal expansion.
If the clearances are insufficient cold, the lash will disappear when the engine reaches operating temperature.
Having no lash will result in the valve being physically prevented from fully closing.
Valves need to be able to close fully against their seats. Obviously a valve that could not fully close would result in compression loss and reduced combustion efficiency.
Not so obvious is that a valve that cannot fully close cannot transfer heat energy efficiently to the valve seat within the head (and into the cooling system where the energy can be dissipated).
Exhaust valves will get so hot that they can "burn" - the metal on the valve face melts and oxidizes.
Compression loss and reduced combustion efficiency can and will result in misfire DTCs and noticable degredation in engine performance and running quality.
Once it gets to the point where the valve has "burned", the cylinder will become "cold" - it is no longer capable of achieving the conditions necessary for combustion to occur.
So, to answer your question: theoretically, a valve that is getting super-heated to the point of "burning" could create pre-ignition and knock, at least until it burns away sufficiently that combustion is no longer occuring within that cylinder.
Since Hondas have been equipped for many years with knock sensors, the PCM / ECM will be adjusting the timing in response to the knock sensor signal, and the odds are better that you'd get misfire DTCs and an illuminated MIL before you noticed any knocking / pinging due to tight valves.
As an aside to the OP, (if you bothered to slog through this little novella) when the MIL is "flashing" that is informing you that the rate of misfire being detected is sufficient to cause damage to the catalytic convertor. Your issue can get pretty expensive pretty quick if you don't get it resolved soon.
thanks honda tech for the explanation.
maybe i'll send u a PM with some questions as i'm not having any luck with a certain issue.
goodluck to the original poster.
mhessick 08-20-2009, 11:23 AM Sorry for the year + follow up . . .
Ended up needing a new head. Honda gave me 30% warranty coverage on an 8 year old vehicle with 77k.
Also ended up needing new timing / water pump, etc.
About $4,000 after everything was said and done.
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