notkool59

Hi, new to the forum! Tried the search, but I can't find anything on my exact scenario. So I put in a K&N filter, just cause it was time for a filter replacement and I like being able to clean and reuse. Anyway, went for a drive and the check engine light came on. Went and bought a code reader, it was code P0302 misfire cylinder 2. Great. Car drives fine, has power, just a little vibrating when a/c is on, but seems normal when no a/c. Took it into Honda, because I was planning on getting a valve adjustment done anyway, and told them of the code. They came back with a compression test of cylinder 1-240, cylinder 2-180, cylinder 3-242, cylinder 4-235. After seeing how low compression was on cylinder 2 and since that is the one mis firing, they performed a leak down test which came back 90% leak on intake. They recommended to pull the head and send send to a machine shop thinking bent valve. Now my question, I have not over revved the car (precious owner may have) but I feel if there was truly 90% leakage, that would be extremely noticeable, no? They did not do the valve adjustment because they said at 90% there would be no point. Thoughts?

lookstoomuch

How long have you owned this car?

windhund116

I'd adjust the valves and redo the compression test.

Chuck S

Which engine is in your car?

Doubt this has anything to do with the air filter.

-- Chuck

notkool59

unfortunately not that long, maybe a month.

yeah, I doubt air filter too, probably coincidence. More curious on the fact that they want to pull the head after seeing 90% leakdown, I mean that's almost like having no valve is it not? I feel like the car would run like crap if that was the case. Its a 2003 ap1, sorry I do not know the name of the engine.

Unfortunately it's not me doing the work, it's honda. Do you think it's worth it to take to an independent shop?

windhund116

I'd take it to another mechanic. Since, the original repair place (Honda Dealer) said they would not do a valve adjustment.

Find a good one. Maybe, you can find one with the help of this board (Communities, toward bottom of the page). Good luck!

chrisaltima

I am facing similar circumstances except my misfire started on cylinder # 2 like yours (P0302), but it turns out my compression is low on cylinder # 3. I read 210/210/180/210. After I cleared the code the first time it came back as a multiple misfire and the 3rd time it came back as misfire on all 4 + multiple misfires. The car behaves normal for the most part but a little "poppier" than usual on the idle.

My next moves are taking it over to Bill a compression test, leak down test, valve inspection / adjustment and see what happens. My valves were adjusted at 23K, my car now has 41K. The first compression test mentioned above was done by a pretty competent mechanic. Hoping for the best!

Good luck!

jyeung528

most likely bent valves up in here.

please report back with findings.

afzan

+1

eight

could also be a sunk valve. find a shop and request to have it boroscoped. that should reveal a lot more. if that's the case then it would require head work.

this is what happened to me, I had 1 or 2 misfires every now and then and compression test showed 150,240,240,240 (roughly) and it was a sunk valve.

what I suggest you doing is perform a valve adjustment, if the misfire goes away then go back and check the valve specs around 10,000 miles later. If that cylinder is showing signs that it's walking out of spec sooner than other cylinders then you have a sunk valve. I found myself needing to do a valve adjustment every 15-20k miles and thus prompted me to check the head and revealed a sunk exhaust valve. your first step in my opinion is to do a valve adjustment and see if it fixes it. dealerships like to jump to conclusions to protect themselves.