CVT fill plug pops out, plugged vent?

34881 Views 44 Replies 24 Participants Last post by jasper60103, 9 d ago

bushlander

Discussion Starter · Mar 5, 2019

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?

21 - 40 of 45 Posts

michael007

· #21 · Jul 4, 2020

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

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Reactions: 1

jasper60103

· #22 · Jul 13, 2020

Interesting. They left off the 2014-15 Civics.
Thanks for sharing.

Sent from my SAMSUNG-SM-G900A using Tapatalk

Reactions: 1

NomadicEntity

· #23 · Nov 16, 2020

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.

NomadicEntity

· #24 · Nov 16, 2020

Sorry, forgot to say it is a 2015 Civic SE

Sverrocc

· #25 · Dec 20, 2020

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

Tyler55

· #26 · Jan 10, 2021

DCFIVER said:
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.

Tyler55

· #27 · Jan 10, 2021

I found

michael007 said:
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

View attachment 492007

Thanks for posting the bulletin. My vent was clogged and the rubber was cracked, possibly from pressure. I'll have to see about replacing the vent cap and I'll see if this stops the fill plug from ejecting.

Tyler55

· #28 · Jan 11, 2021

I cleaned out the vent cap, went for an hour long drive and the fill plug hasn't popped out! Thanks for the help.

Oregono

· #29 · Jan 11, 2021

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.

Tyler55

· #30 · Feb 9, 2021

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?

Orenburg007

· #31 · Feb 15, 2021

Tyler55 said:
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?

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.

Tyler55

· #32 · Feb 15, 2021

Orenburg007 said:
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.

The fluid had been changed once before I started noticing the vent plug popping out. I took out more fluid than I put in when I changed it again. I filled it until it came out the check hole. I was on the levelest ground in my neighborhood, my driveway have a good slant on it so I took it to some visitor parking spots. The engine was hot when I took out the fluid but the temperature outside was around freezing when I put in the new fluid. It might be the case that the last person overfilled it and then I overfilled it too based on it not being completely level and the new fluid being cold.

Orenburg007

· #33 · Feb 16, 2021

Tyler55 said:
The fluid had been changed once before I started noticing the vent plug popping out. I took out more fluid than I put in when I changed it again. I filled it until it came out the check hole. I was on the levelest ground in my neighborhood, my driveway have a good slant on it so I took it to some visitor parking spots. The engine was hot when I took out the fluid but the temperature outside was around freezing when I put in the new fluid. It might be the case that the last person overfilled it and then I overfilled it too based on it not being completely level and the new fluid being cold.

Do you remember how much fluid you poured in?

Oregono

· #34 · Feb 27, 2021

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.

Reactions: 1

jasper60103

· #35 · Feb 27, 2021

Oregono said:
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.

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bushlander

Discussion Starter · #36 · Mar 17, 2021

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

Oregono

· #37 · Mar 18, 2021

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.

tomb

· #38 · Jun 16, 2021

Kerrington said:
I have a 2014 civic and mine keeps popping out. It’s aggravating. I don’t want to replace a transmission but it sounds like Honda needs to answer why?

I also have a 2014 Civic 4 door with CVT and the plug has been popping out for several years. Every time I check it's popped out.

jasper60103

· #39 · Jun 17, 2021

tomb said:
I also have a 2014 Civic 4 door with CVT and the plug has been popping out for several years. Every time I check it's popped out.

Some have reported success with following the service bulletin mentioned earlier in this thread. Zip tie for extra measure.

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deonika7

· #40 · 5 mo ago

Sverrocc said:
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

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