Hey all, problem just started out of the blue on commute home from work. Suddenly had a gassy exhaust smell coming through the air vents when I stopped at a light. I thought it was the car in front of me but no luck. When I turn on recirculation it pretty much disappears. Gas mileage seems the same. I have had it to 2 shops to check for a gas or exhaust leak and neither found anything. They both smelled it. I changed the cabin filter for grins. Engine seems to be running normal, but the smell is nauseating so I keep blower off, or on recirculation with windows cracked a few inches. If I travel over 20mph, I don't notice it.

 

Spark plug(s) loosened up?

 

what year is your fit? my wife's is a 2013 with about 55KM on it and we have been having this problem intermittently for over a year. initially brought it to the dealer's attention last year because it was still under warranty. they cleaned around the engine compartment and told us to come back if it came back. what's strange is it would go away for a few weeks and then come back. we only smell fumes (more exhaust smell than uncombusted gasoline fumes) when the vehicle is stopped and the fan is on outside air. this almost certainly means the leak is coming from under the hood and it takes a few seconds at idle before the fumes make it up to the outside air intake which is on the outside of the car at the bottom of the windshield. there is no perceptible smell when driving around--we can be on outside air 100% of the time as long as the car is moving and there are no fumes.

anyone else having this problem??

 

Loose spark plugs, almost certainly. Dealers have no clue, but this seems to be common on fits. Most noticeable while idling at a light. I Never would have believed it myself, dealer unable to figure it out after numerous visits. Found this info somewhere in this forum, checked myself and the plugs were very loose. Hard to get to, but if you're competent it is a diy fix. Unbolt the coils from the top of the head, remove the coils from top of plug, then tighten. Not sure of torque spec for this, but my understanding is that the head is aluminum so be careful.

 

Fix it now. Do NOT wait. If it loosens to the point of blowing out, you will be looking at a very high bill to fix the threads in the head. This has happened to many Fit owners and Honda seldom warranties the fix.

Re-torque the plugs today. You are lucky that you noticed it before it blew out the plug.

There are many threads on this forum about the problem.

 

This is exactly what happened to our Fit. Our son who drives the car the most said he could smell exhaust. Number 3 plug halfway out.

 

we also have an occasionla mouldyish smell, from the ac. I also had a swishy water sound from the dash. It was the condensate not draining from the ac system. There is a little black tube that goes from under passenger side dash through the floor/firewall and drains out at the back passenger side if the engine compartment. Our was blocked. I unplugged it by squeezing it, and a gallon of water drained out. You can see the end of the tube under the car. You can get at it from inside or gently slide a long screwdriver up the tube from underneath. Fit AC is weird and problematic, this is just one of the quirks I have never noticed in the many other cars I have owned

 

So the fit finally threw an engine code for misfire. Looked online again. Said ignition coild go bad. Order one for 45 bucks. Took apart last weekend and number 3 and 4 were scorched. Went ahead a replaced 3 and ordered another. Engine code went off for 2 days. Came back on. Just replaced 4 and bought a spark plug socket extension. Spark plugs 3 and 4 were really backed out. That's insane. Never had car do that. Replaced that second coil. Hopefully not too much or any damage to motor. Gassy exhaust smell is gone, mpg back up, and sounds right. I can't believe dealerships and other local repair shopen don' know this.

 

The misfire code does not indicate a bad coil...rather only a misfire is occurring. The cause could be a bad coil...or a bad plug...or a plug getting ready to blow out of the head because it has backed out. Any indication of a scorched coil indicate exhaust leak caused by a loose plug. Ours was scorched but worked perfectly after cleaning it up and replacing the loose plug with a new one properly tighten.

 

Wow! You got lucky! Ignored the good advice that was given 7 months ago to check the plugs.

It's a known problem with these cars. You got very lucky that it didn't blow the plugs out of the head and remove the threads in the process. For some, that's the road to a whole new motor.

 

yeah, I think I did get lucky. I took it to a shop and a dealer and neither could find anything. I am pretty handy but had never tackle anything like this. It was easy. What' sad is i mentioned spark plugs and ignition coils to both places and they blew it off. Once the light tripped and it was tuttering I started messing with it myself.

 

I just started to experience a raw fuel smell in my car, but only when it's running. Especially noticeable now that it's cold and I have the heat running. I took to my mechanic and initially he dismissed the idea of it being the spark plugs. He wanted to check the fuel system first and thoroughly went through everything no leaks or loose fittings.

How likely is it the plugs, my mechanic is willing to do it, but is concerned it won't solve the issue especially with how time consuming it can be on the 2nd gen fit. He gave me a reasonable price to do it and is willing to. Should I go for it? Please note that I live in the city so I can't DIY no space to work on cars/would rather have my mechanic do it.

 

If you read this thread, then you know the problem. Buy a couple of wrenches and do it yourself, or take it some where and have them torque the plugs to specification. Total cost will be 1/2 to 1 hour labor now, or thousands of dollars in a few weeks what it blows out and destroys the head, plug, and coil. Many people have reported the gas smell just prior to the plug being ejected. I would not drive that vehicle anywhere, even to the mechanic, until it is fixed. It is your money, spend it however you want.

 

Any mechanic that can't check those plugs in less than 45 minutes is a hack. If your a mechanic ofr a living you have a
3/8 x 10 In torque wrench or a standard ratchet with a 18 or 20 ft lb torque rod..
FWIW,, if you read the box the plugs come in,, with clean threads,, screw in hand tight and then tighten 1/3 of a turn. (plugs with washers) If you do the match 1/3 of a turn from first contact works out to be between 18 and 22 foot lbs..

 

When I fist read about the issue I never thought this would happen to my sons car. Fortunately we caught it just in time. Not only did he detect an exhaust smell (and had for a few weeks), but it threw a trouble code (misfire) too. We immediately decided to change out the plugs and did a valve clearance check while we were at it. Out of four plugs we found two that were loose, with one of them more than half-way out! Lots of soot on the coil plug. I'm glad that car is gone.

And by the way, when a plug starts working loose and begins to back out of the threaded hole, good chance you will get a mis-fire code. Not always...but if you are lucky you will. It will misfire because the firing of the plug is now up inside the threaded hole, rather than right on top of the piston. Never ignore that warning. Stop driving immediately..

 

I just had my mechanic inspect the coils/plugs and replace the plugs for good measure. The only thing he mentioned was that the plug #4 closet to the driver's side was looser than the other, but not nearly as bad as other's are describing. Nothing noticeable about the coil packs. I'm still getting a slight gas smell. Car runs absolutely fine, smooth idle and did before without a trouble code. Gas mileage is great. Issue seems worse in sub 30 degree weather. I'm going to have the shop check it over one more time, but for now I'm loosing my mind over this. Car only has 67,000 miles. I live within walking distance to a Honda Dealer - considering calling them. but they always give me the hard sell on unnecessary maintenance even when I went in for the air bag warranty.

 

It doesn't take much to get a fuel smell. Most likely the leak is any "joint" within the pressure side of the fuel system, even around an injector. This can be an issue due to cold weather, which can go away when it gets warmer. If the car is under any kind of warranty, I would take it to the dealer. I don't know if they have an electronic "sniffer" like they do for Freon, but perhaps.

 

@Spacecoast Unfortunately the cars well out of warranty, but I did go to the Honda dealer today and talked to the service manager who was super helpful and gave me a lot of ideas (w/out pushing me to service there) - he said the first thing to check was the fuel injector O-rings which would be a super cheap fix. I'm bringing it back to the mechanic I've been working with to see if they have the sniffer or are willing to partially refund me for the spark plugs since it didn't fix the issue if it is indeed just o-rings. Unfortunately, I only have street parking so I have no space to work on the car myself so I'm at the whim of mechanics.

The original theory they had was like suburaus where the fuel line contracts in the cold and the connection gets loose - not the case here tho.