I have a 2004 V6 6-speed Accord with 63K miles, bought new and babied for all its life. About a year ago, my CEL lit up so I pulled the codes. I had a misfire on all cylinders and a random misfire code. I cleared it and didn't see it again until recently.

In the last few months CEL has lit three times. Twice I ignored it and it went away on its own within a few days. The other time I pulled the same codes again and cleared them. Lately, after clearing or after simply waiting for it to turn off, it will light again within 2 - 3 weeks. It always seems to light right after starting, never while driving.

Other than idling slightly rough when cold, which may be normal, it runs just fine. No hesitation when accelerating, good mileage, reliable starting. I have done lots of research on this and have came up with bad plugs, a bad coil, even bad gasoline or the need for valve lash adjustment. Yesterday, after pulling into my garage, I popped the hood to listen to the idle when the engine was hot. It sounded fine, although a little "clickity", which again, might be normal. I don't remember how it sounded new.

I called a local Honda dealer to ask them about the valve adjustment, and they said they rarely have to do it. I also called another dealer in my home state over 1000 miles away and they said essentially the same thing. Various Internet forums talk about having to do valve adjustment much earlier than the recommended 105K interval.

Is there a consensus on this valve adjustment thing? Is there a way to tell if adjustment is needed by monitoring certain PIDs via the diagnostics connector? Have any of you experienced the same problem, and if so, what was the issue? So far I have replaced nothing on this car attached to the engine, other than oil and filter changes.

 

Yeah, I have to adjust lash on the Civic about every 60K miles. If it sounds "clickity" it probably needs an adjustment. You've got low miles for a 9yo car so, I'm leaning towards carbon buildup. I would look into what the O2 sensors are reading. If the sensors or cat is going bad then it could mis-fire. Also, check and clean (if it needs it) the EGR. You can also check fuel pressure, injectors, and compression but, i would start with the other stuff.

 

Clean out the EGR first. They can get gummed up and stuck open, which cause a misfire at idle or when you first turn the car on. This happened on mine and once I cleaned it, everything was okay. If the CEL comes back on after its been cleaned then look into the valve adjustment. Get carb or intake cleaner and a small flat head to clean the carbon build up around the opening.

 

Good suggestions from you both about cleaning the EGR. This certainly is easier than adjusting the valves first.

 

I'm not being a smartass, but you could pay for some diagnostic time and ask them if they have a scanner that can read live data to see what's going on. At least that way it'll give you everything you need to know when the light is coming on and when it's idling a little rough when it first starts. Once they find out what's going on with it at least you can fix the problem instead of wasting time trying to do this and that when it MIGHT not work. Just a suggestion that's all.

 

Can it be valve adjustment sure but these lifters are all mostly hydraulic for Hondas which have a zero lash, these things can be even moved slightly by improper oil maintence. EGR / carbon buildup would be safe checks as well but if no dice work your way back off the EGR ->Dpfe Sensor which will work as an input to the PCM on the differences of pressure in the exhaust. Last would be the solenoid off that system. Just giving you options.

@intense why would he burn money for no reason sure hell find some free time to do something. Plus it's a learning experience.

 

The experience would be great, but he mentioned that it's been going on for the past few months that's the only reason why I would suggest that. Some ppl don't have the $$$ to pay for a diagnostic and if that's the case that's fine.

 

Lol that's why he's here silly

 

My vote is for valve adjustment. They are NOT hydraulic.These engines are notorious for misfire issues with regards to valve lash when cold.. In fact I believe there is a TSB about it.

 

x2 this is a more then common problem with the J30. And misfire codes on all cylinders unaccompanied by another code or lack of power/hesitation are mechanically related.

 

I have the money to buy an entire new car, but that doesn't mean I like spending it unnecessarily. It's not urgent, and I don't entirely trust mechanics (or everything doctors say for that matter but I won't get into that). I like doing my own research first.

Since the light last went off by itself, I've driven about 800 miles and no light yet. But I'm sure it'll rear its ugly head again eventually.

 

Taking off the EGR and cleaning it takes all of 15 minutes. Its much easier to eliminate that issue than spend $400 to have the valves adjusted, or 2.5hrs of your time and have the same problem.

 

Haven't checked up on this in a while. Anything happening?

 

Light hasn't come back on since, and haven't had any time to do much with it. Not to mention living in an apartment temporarily makes car repair difficult.

 

I've set the valves on my engine. Yes, they were a little off, but nothing that would cause a misfire. I would clean the EGR first, it's not going to take nearly as much time and effort.

Hydraulic lifters? No, there are no lifters at all.