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CVT fill plug pops out, plugged vent?

44K views 46 replies 25 participants last post by  bernulli 
#1 ·
So I did an oil change yesterday and I noticed my fill plug was on top of the CVT... Kinda scared so I got some HCF-2 to change it out today and it has popped out again after 100 miles?

I've searched and found a few people that mentioned the same issue but no solution.

Anyone have some insight?
 
#4 · (Edited)
mine popped out...it was on the garage floor. i didn't realize what it was....held on to it for a bit. finally, gave up, threw it out. 2 weeks ago, i was making sure they changed the brake fluid as i paid for that as well as the tire rotation and such. next thing on the my list to do was change the transmission fluid, so i looked down there and no plug. i was like, wtf! i immediately thought the dealer had forgotten to put it back on when they did the comprehensive multiple point inspection few months back. i couldn't prove it, so i had to buy it myself. i got on line, looked up the part and then i realized that was what i threw out in the trash. it had popped out in my garage. i called to get a new one...it ranged from $17 to $26 at various dealerships. the parts lady asked my name and noticed i had just been in there recently, a few times. i said, yes, and the next thing i was going to do was the fluid change. she told me she's order it and no charge for me and to have me come pick it up. how nice of her. that's how you keep customers, in my mind.

anyways, this seems to be an issue. i'm thinking of rigging a safety wire to the new one so if it does pop out, it won't be lost.

but first, i have to get the front end repaired...got tagged Sunday morning. 17 yr old kid in '06 civic going way too fast in the snow and lost control and slammed into me. he was trying to turn right, as i was leaving the neighborhood. dash cam proved to be useful to the police!
 
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#5 ·
I just checked if mine was still there since I did a fluid change about 30k miles ago and it is. I wonder why they are popping out? I'm glad you're okay. Kids need to slow down!
 
#9 ·
i may get one of those just in case. it's half price of the replacement and at first glance, appears to be a better solution than the original.
 
#12 ·
I just found mine missing and assumed the tech at the dealership forgot to reinstall it (6 months ago). Called them and they are replacing it and doing another flush tomorrow, no charge. Should be a recall on this. I'll contact Honda North America Customer Service for good measure.
 
#15 · (Edited)
What year(s) are these vehicles? Im curious if it is happening across the board or only certain years.

The fill plug will typically pop out if the fluid is over filled or the breather/vent tube is plugged.

However it could also simply be a crappy design. Not the first time.

ATF dipsticks on late 90s to mid 2000 Civics also would pop out as the dipsticks started to age.
 
#26 ·
What year(s) are these vehicles? Im curious if it is happening across the board or only certain years.

The fill plug will typically pop out if the fluid is over filled or the breather/vent tube is plugged.

However it could also simply be a crappy design. Not the first time.

ATF dipsticks on late 90s to mid 2000 Civics also would pop out as the dipsticks started to age.
I've got a 2014 civic touring 1.8L and it keeps popping out every time I drive.
 
#17 ·
it's models with the CVT transmissions.

i have begun checking mine every month when i check the oil, refill the tires, etc.
 
#18 ·
I had the same thing. I changed the fluid a year ago on my 2015 Civic with CVT. Recently, after a trip, it was sitting in the garage and I smelled the strong aroma of tranny fluid. Popped the hood and the fill plug is resting peacefully next to the hole. (??) I thought that I better check the fluid and made the stupid mistake of not warming the engine first and about a quart of expensive HCF-2 came flowing out.
 
#20 ·
so, i changed my transmission fluid again yesterday. aside from a multitude of other issues....the fill plug had popped out and was laying next to the hole. i hadn't checked it since march since i've hardly been driving it now that i've been approved to work from home. but this is obviously an issue for the CVT transmissions. i'm presuming since it's such an easy "put it back in", Honda isn't aware of the gravity of the situation.

just a friendly reminder to check you plugs!

no issues with the CVT so far at 131K miles.
 
#21 ·
I created an account to let y'all know there's a Technical Service Bulletin about this issue:

https://static.nhtsa.gov/odi/tsbs/2019/MC-10165374-0001.pdf

I asked my dealer if there was a TSB and they said no....

My HRV had the exact same issue and thanks to this thread, I figured out the cause of the fill plug popping out twice.

The cap for the breather vent was clogged shut (photo from my car can be found in the following link)
Transmission Fluid Plug

492007
 
#23 ·
Just found this happened to me today. Was trying to figure why I was getting some hesitation in my shifts. Cap was just sitting on top of the body next to the hole. I was hoping the shift issue had something to do with it. It seemed a bit better going from first to second but I still have something to worry about cause irs a little rough still on the higher one. Thanks for letting me know a replacement is the way to go. I'll grab one tomorrow.
 
#25 ·
My friend had this issue. He took it to the dealer and they replaced the plug. Told him they had no idea why it happened. They didn’t recommend changing the fluid and they charged him to replace the plug. A couple months later the transmission failed, and I assume this was due to all the contamination that entered the transmission while the plug was out. In my opinion, Honda needs to replace the transmissions for people if the plug ever comes out. A minute amount of contamination in a hydraulic system can cause permanent damage.
My buddy has 4 kids and really couldn’t afford for this to happen. F**k Honda
 
#40 ·
My friend had this issue. He took it to the dealer and they replaced the plug. Told him they had no idea why it happened. They didn’t recommend changing the fluid and they charged him to replace the plug. A couple months later the transmission failed, and I assume this was due to all the contamination that entered the transmission while the plug was out. In my opinion, Honda needs to replace the transmissions for people if the plug ever comes out. A minute amount of contamination in a hydraulic system can cause permanent damage. My buddy has 4 kids and really couldn’t afford for this to happen. F**k Honda
Right so true I’m going threw Sam thing single mom and have not my car a year
 
#29 ·
Today will be day 5 of owning my 2015 Civic. The night I bought it saw the fill plug missing. The dealer I bought it from said they found it laying on the transmission. They say they serviced the transmission and it's fine. Yesterday the plug was out again.
Honda Service bulletin A19090B States this is a know issue. The CVT transmission vent is plugged/ blocked. They say to simply pull the vent plug and clean with compressed air and reinstall. It also says to replace the fill plug if it appears to fit loosely in the transmission. Guess I am heading back to the dealer to give them a 3ard chance to get this right.
 
#30 ·
I'm back, the fill plug came out again.

I cleaned out the vent cap. I drained the CVT and filled it with new CVT transmission fluid. This was about a month ago.
Last week I started smelling burning transmission fluid when I got off the highway and to work or home. When I slowed down from high speed I smelled it. Wasn't sure what the smell was at first because I work in the harbour between a steel plant and an animal fat rendering plant, lots of different terrible smells around. I popped the hood and the fill plug had came out and fluid was around the hole. There were some traces of fluid around the vent cap too.

This makes me think that there is something else wrong with the transmission. Is it over-heating the fluid to make it expand more than it should? I filled it till fluid came out the check hole so I know it's not over filled. Why is fluid pressure ejecting my fill plug and coming out of my vent?
 
#31 ·
Have you changed your Tranny fluid in the past, or did this started happening with the factory fluid fill? I am asking because this seemed to start happening after the first time I changed the transmission fluid. Since there is no dipstick, and no accurate way to measure the proper amount of fluid to put in (the check hole is a joke, for it to work the car has to be perfectly levelled, and fluid temp has to be just right), i am thinking perhaps we are overfilling the transmission? I saw the bulletin, but my vent cap is not clogged up, and the fill hole plug is still popping out.
 
#35 ·
For what it's worth, I did get a new fill plug from Honda. Very tight fit compared to the one that kept popping out. It fit very loosely. The new one was tough to get in. Still there after a month. I drive freeway 5 days a week. 50 miles per day. 70-80mph. So far so good.
Glad the problem is resolved.
On my 2015 civic, I recently discovered my plug slightly raised, not popped out.
I cleaned the vent cap. I’m not sure if it was clogged. I zipped tied the fill plug down and
will continue to monitor.
Thanks for the update.


Sent from my iPhone using Tapatalk
 
#36 ·
Just an update. I got a new plug from the dealer to replace the one that kept popping out. For the past year the new plug has stayed in place but I still check it every time I open my hood.

however I now have a rattle in my engine compartment everytime the car idles in gear with the brakes engaged. I sure hope that missing plug didn't prematurely kill my CVT. I've done regular fluid changes as per the manual but there is something wrong in there I'm going to need to diagnose.

2015 Civic EX Auto CVT @ 177,000 km
 
#37 ·
Does the car drive differently? Do you notice any performance issues? Stalls, hesitations and such?
Does the rattle seem to come from one area in general? There are a lot of components that are under a load with the car in gear with the brakes on.
I get it. I've only had my 9th gen Civic for almost 3 months now. Every time I feel anything weird it's a little unnerving. Still trying to get use to the feel of the CVT transmission. The only reason I am not freaking out is the car came with a pretty comprehensive warranty.
If you have any mechanical skills, I would suggest warming up the engine, temporally remove the serpentine belt and briefly start the engine, put your foot on the brake and put it in gear to see if the noise goes away.
At least that would rule out any thing the serpentine belt rotates or rides on. Best of luck.
 
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