Not sure where to post this as I am not awesome with cars, but my 2008 Fit Sport (MT) just threw a code indicating a problem with the 4th Cylinder. Took it to the mechanic and he thinks it might be carbon build-up on the intake valve. Does anyone have any idea how much it might cost to fix this? He is going to charge me $80 to actually diagnose it (this isn't a for sure diagnosis - they just looked around at it today), but he said the symptoms fit. The check engine light has been going on and off for the past month and a half. It goes on for a couple days and then goes off for a couple days. When I don't warm it up long enough, the engine dies when I am coasting to a stop (it ONLY does that when it is cold). Anyway, I am kinda freaking out because I have only had the car a few months and am scared I got a lemon. Can anyone help?

 

Post the codes here. Online diagnosis is even harder than diagnosing via sound effects by mouth.

How many miles on the car?

 

Those symptoms are similar to other's who ended up needing either a valve adjustment or new coilpacks. Google terms like "honda fit cold stall" and you'll find a lot of threads on Fitfreak about it.

 

The code is P0304.
Also - I put Seafoam in it yesterday morning and the check engine light went off again. It hasn't gone back on yet.
It has just under 81,000 miles on it.

 

Cyl # 4 misfire.

Change your spark plugs. Problem persists? Adjust valves.

That doesn't fix it? Replace the coilpacks.

 

I put Seafoam in several days ago and the check engine light hasn't come back on. Is it possible that this has solved the problem?? I am going to wait a few days to take it back in to the mechanic...hoping that this is all it will take because I am super short on cash.

 

Finally able to take it in - the mechanic diagnosed two bad coil packs. He suggested that I replace all 4 for $500, but option to replace just the two was $300. I am not good with cars so I am not able to do them myself. I just went with doing the 2 for budget reasons. FYI to all of you who have written in on this and other threads - this forum has been really helpful! I was able to get a lot of information and gave the mechanic a couple ideas of some possible problems with the car. I really think I helped narrow it down for him by mentioning the coil packs - he had it diagnosed about a half hour after I dropped it off. Anyway, hopefully it will be good as new when I pick it up. Thanks again to all of you!

 

You could have saved yourself some money by doing the coil packs yourself. All you need is a screwdriver, a wrench, some dielectric grease, anti-seize and some patience and you're good to go. They're only held in the cylinder head by one screw and there is one electrical connector to plug.

Just some FYI for if you need it done again in the future.

 

That is good advice! I already talked to my dad (he is better with cars) and he will be out here to visit in a few weeks. We plan on messing around a little to take a look at the other two coils to see if it is something I can maybe do on my own when they end up going too (seems inevitable at this point!). Hopefully I will get the ability and confidence to do them by that time!! Thanks again!

 

Update - the two coil packs seemed to work, but only for about two days. Although the CEL isn't back on, the car is jerky on start-ups and stalls when cold again. So, I am going to change out the other two coils (and spark plugs while we're at it) with the help of my dad next week. Wish me luck. This has been a frustrating journey.

 

Changed the other two coils and the spark plugs about 6 days ago, and no issues yet. Fingers crossed that this does it...

 

From now on, if misfiring or stlaling or cutting off is an issue, go to walmart, buy the $30 red and blacj multimeter, and look up online how to test the coils.


Much cheaper then a $80 charge for them to do the same thing.

Plus you gain knowledge and satisfaction that you fixed your car!!



If the light comes back on, buy 2 bottles of the cheapest fuel injector cleaner. This stuff is diluted a ton, which is why they can get away with telling you to do it every gas tank fillup.

Pour both into a 3/4 or full tank (cuz our tanks are small) and try to run it down to 1/4 tank in a short time (id say no longer then a week)

Then fill up with normal gas and continue on knowing you got a little bit cleaner engine.

also, if you buy spark plugs that can be gapped (google it) you can gap them shorter. example, if they say gap .044, try a gap of .04 its not a huge difference, it will simply take a few thousand miles of life away from the spark plug, which is fine because they can easily last over 30,000 miles

 

^ I say don't waste your time or money with the fuel injector cleaner. I've never seen it solve anything.

 

Car stalls when cold = valve adjustment

Yes, it could be carbon buildup on the valves, but I'd go with the most obvious fix. The valve adjustment issue is extremely common for 07-08 Fits, so your chances are better starting with that rather than trying to clean the carbon (if there even is a substantial amount).

 

Doc is right on both counts again. Tried to give you some rep but got the "must spread it around message".

 

Honda mechanics have made a lot of money putting new coil packs on Fits that didn't need them. I had the same stalling when cold problem a couple of years back and wrote it up here.

I refused to buy the recommended coil packs as it was a "guess" repair. Instead I adjusted the valves (45,000 miles on the car) and fixed the real problem. The valves were staying open when cold reducing the compression and allowing the engine to stall. Once the cylinder head and other parts expanded with heat the valves would just close. Fixing the valve adjustment took care of that.

Never just throw parts at any car guessing what might be wrong. Get back to basics. The engine has to be mechanically fit (pun intended) before the other systems like fuel and ignition will work. I can not tell you how much money has been wasted on vehicles by so-called mechanics guessing at what is wrong.
As the Sun Diagnostic Equipment people use to say, "Test, don't guess".