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Hi boys. I've had a problem with the engine misfirng severely. I got a diagnostic check or something when my A/C Blower Motor went out, and got 3 misfires. I'm not sure if it was 1,3 and 5, or 2,4, and 6, but it is one entire side. This weekend I will be checking the spark plugs and coils, but wanted to see if anyone had any other suggestions? Thanks
 

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If the check engine light came on, would be helpfu to know what misfire codes you got. Also helpful to know if it happens all the time, just when the engine is cold, under acceleration, if it’s sat for a few hours, etc. Misfiring and the conditions around it could point to different causes.

Note if any plugs are loose. Some cylinders seem prone to it. Label your plugs from the cylinder and inspect them.

Put the ignition coils back on the same cylinder in case it’s more than the plugs.

How many miles? When was the last time plugs and timing belt was changed? When was last valve adjustment?
 

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If the check engine light came on, would be helpfu to know what misfire codes you got. Also helpful to know if it happens all the time, just when the engine is cold, under acceleration, if it’s sat for a few hours, etc. Misfiring and the conditions around it could point to different causes.

Note if any plugs are loose. Some cylinders seem prone to it. Label your plugs from the cylinder and inspect them.

Put the ignition coils back on the same cylinder in case it’s more than the plugs.

How many miles? When was the last time plugs and timing belt was changed? When was last valve adjustment?
The check engine line is continuously on, and I have yet to check the engine codes as I'm still in High school, but hope to be scanning the engine after school. X has 174k miles. I don't know when either the plugs or valves were inspected as my dad just gave me the car. However we did have a shop recently look at the timing belt when AC motor needed help. No problem.
 

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Definitely find out from your dad when/if the valves were adjusted. The manual makes it sound like you only need to do it if they get noisy, so a lot of people ignore them until then, but the valves on these engines tend to tighten up (which don't make noise). If it's never been done on your X, it's overdue and could be causing misfires (and even if they're not, it's still good to do them).
 

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Great to hear you’re a young person taking some responsibility and trying to find out more about your car.

In case my earlier post wasn’t clear, when I wrote, “when it happens”, I meant when and under what condition it misfires, not when the check engine light comes on. (Looks like I need to go back and take high school English.)

Plugs, timing belt, and valves are supposed to be serviced at 105K miles.

The first valve adjustment on my 2006 was at approx 85K associated with check engine light and second was at approx 140K though only a few exhaust valves were slightly out that second time.

Good luck!
 

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Great to hear you’re a young person taking some responsibility and trying to find out more about your car.

In case my earlier post wasn’t clear, when I wrote, “when it happens”, I meant when and under what condition it misfires, not when the check engine light comes on. (Looks like I need to go back and take high school English.)

Plugs, timing belt, and valves are supposed to be serviced at 105K miles.

The first valve adjustment on my 2006 was at approx 85K associated with check engine light and second was at approx 140K though only a few exhaust valves were slightly out that second time.

Good luck!
My bad I didn't understand. So my friend who has much more car knowledge than me, know the situation of the misfiring, and said he could hear it while I was parked. As for any other conditions, I'm not sure as I usually have music on but I will try to get a few drives in on silent. However, I don't notice much power loss when ever I'm accelerating. I did scan the engine today with my same friend's Engine Scanner. Got codes P0420 and P0430. I know those are catalytic converters but not sure where to go from here. As for latest servicing, I'll see what my dad's situation was, but he actually bought the X used, 4ish years ago from Chicago over 100k miles. Thanks for the compliment BTW, just tryna learn more about cars and how to fix problems "myself".
 

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Strange you didn’t get any misfire codes like P030X. Maybe you don’t have a misfire.

Search this forum and the web for the codes. If it really is misfiring, also try searching for misfiring, rough idle, etc. There are posts that list potential causes.

You should try to find out what it really is and when it happens - diagnose the problem. Else you risk unnecessarly changing parts until the problem goes away.

Good luck!
 

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Strange you didn’t get any misfire codes like P030X. Maybe you don’t have a misfire.

Search this forum and the web for the codes. If it really is misfiring, also try searching for misfiring, rough idle, etc. There are posts that list potential causes.

You should try to find out what it really is and when it happens - diagnose the problem. Else you risk unnecessarly changing parts until the problem goes away.

Good luck!
Will do thanks man
 

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Own a 2002 and 2007 MDX. On our 2002, I spent a lot of time trying to diagnose misfires on my own with a scanner - at 125-130k miles. Replaced plugs, played the coil game, etc. Boiled down to a valve job. Some were getting way out of spec. It's a proven issue. It also just ran much better afterwards.

I started to have the problem on our 2007 at 115k miles. Without hesitation, valve job, and on we went.

It sucks. Just do it, or have it done. You'll appreciate the time saved trying to fix it with smaller measures that don't address the root issue. My $.02.
 

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Own a 2002 and 2007 MDX. On our 2002, I spent a lot of time trying to diagnose misfires on my own with a scanner - at 125-130k miles. Replaced plugs, played the coil game, etc. Boiled down to a valve job. Some were getting way out of spec. It's a proven issue. It also just ran much better afterwards.

I started to have the problem on our 2007 at 115k miles. Without hesitation, valve job, and on we went.

It sucks. Just do it, or have it done. You'll appreciate the time saved trying to fix it with smaller measures that don't address the root issue. My $.02.
Did you fully replace the valves?
 

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Did you fully replace the valves?
why would you replace the valves? Unless your timing belt broke and a piston impacted valve(s) then no replacement should be necessary.

A valve adjustment simply adjusts the "lash" (clearance) of the valve stem and rocker arm to be within the manufacturer-specified limits. Over time, this adjustment goes out-of-spec which can affect fuel economy, how well the engine runs, and eventually lead to more serious damage.

I think it's good-practice to perform a valve adjustment when doing a timing belt.
 
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