Hi, I found a link to this thread on Google. I've got a Honda with CVT. In this thread you mention problems people have had including rumbling when you accelerate from a start. This happens with our car, the initial rumble is quite severe, then there is a second rumble a moment later. It is worse when the engine is warmed up, and only happens when starting from a stop, never when accelerating even from a very slow speed.

I have been looking up about how CVT engines work, and am still none the wiser as to the reason for this. You mention that flushing the transmission fluid fixes this problem. Why is that? What appears to be the cause of this problem? If the transmission fluid being flushed fixes it then it appears not to be a major problem. Hopefully.

I appreciate that this thread is quite old but would appreciate a reply as I am not getting anywhere in trying to find reasons for this problem and answers to fixing it.

Thanks.

 

CVT (continuously variable transmissions) refers to the transmission, not the engine.

When I looked over the long term reports on various Honda hybrids at http://avt.inl.gov/hev.shtml, it seems a # of them had their transmissions and catalytic converters fail in the 90K mile range. So, this isn't that surprising to me.

 

Hi Slavi,

I had the same exact rumbling problem you had in my 04 Civic Hybrid with a CVT for the past 6 months, but it kept on getting worse and worse. Finally at 41k miles, I brought the car in for the regular oil/filter/lube today at my Honda dealer and asked them to look at the transmission (do a diagnosis).

They said they had to burnish the starter clutch, and the 7-year/100,000 mi warranty extension that Honda mailed me in summer of 2007 covered this issue entirely, described as "CVT judder or slippage," which would be repaired for free under warranty. The guy who serviced my car said that this was one of a number of 03-04 Civic Hybrids with the same exact problem that they saw in their service center.

To fix this problem, bring your car in for service, and make sure you go for a drive test first with a service rep and show them the exact problem in a parking lot. They'll do a diagnosis (normally $125) but waive the fee and fix the problem for free if you're covered under that extended warranty for the issue.

The guy told me that normal use of the CVT transmission wears down the starter clutch, and this may cause slippage when accelerating from a stop. This was the problem in my case, and they just had to burnish the starter clutch - took about 5 hours in addition to an oil/lube/filter. I might have to do this every 40k...

For other people, the service rep told me that the problem was that customers would take their CVT Hondas to Jiffy Lube or other places to get an oil change, and the place would top off (mixing the original CVT transmission fluid with automatic transmission fluid) or flush out the Honda CVT transmission fluid with automatic transmission fluid. Using the incorrect automatic transmission fluid in a CVT transmission will cause all sorts of judder and slippage because it's not the genuine Honda formulated fluid and is designed for a different kind of transmission. So make sure you are using only genuine Honda CVT transmission fluid in your vehicle, and not regular automatic transmission fluid or any mixture thereof.

Hope that helps! And by the way, my CVT works quite smoothly now

If you would like to learn more about Honda CVTs, there's a great explanation by Honda here:
http://world.honda.com/automobile-technology/CVT/
Compared to a normal geared automatic transmission, the pulley-belt system in a CVT needs a special formulation of lubricant to run smoothly.

 

Judder/slip with vibration happened about a year and a half ago. They fixed it right away, no problems. Now I have a knocking going on in engine compartment, they also thought it was a broken engine mount, swapped those out and that did nothing to solve the problem, finally they burnished?/flushed the transmission, that changed it from feeling like a broken engine mount to a slipping transmission. But now they went on a drive with me and they are insisting there is nothjng wrong wihh the car...

 

My father has a 2005 HCH with CVT. (GEN one). About two years ago honda sent my dad a letter saying the warranty on the CVT was upped to 7 years or 100k miles. We live in Massachusetts. At about 65-70k or so I started feeling a jolt between 0-10 mph during acceleration. We recently had the problem fixed under warranty. They replaced the clutch assembly after burnishing the clutch did not solve the problem. We are now at 78k and so far so good.

 

I'm back, transmission still on its last legs. They are considering repairing my transmission... Went on a ski trip and the colder environment made the malfunction worse

 

So the general theme I'm getting from this thread is that the transmission issue may be caused by incorrect trannie fluid. Sounds like some expensive consequences, no? I guess the other theme I'm getting--the shorter warranty not covering some people's problems--isn't exactly getting resolved with a reason or resolution. But it almost seems like both themes are due in part to the same behavior.

Now, I'm not saying that the owner is exclusively at fault here. I'm a new owner myself with 35K miles, but I'm just trying to digest all of what you guys are saying about your own HCH-I vehicles.

I was told by the original seller of my Civic that they exclusively took theirs to the same dealer. In turn, they never had a single problem. *shrugs*

 

Always took it to dealer never got wrong fluid...
Fully reversed loads break everything, our transmissions will fail

 

What do you mean by fully reversed loads?

 

You used the transmission to accel and electrobrake
no other transmission has to handle torque in both directions
note reverse is a separate gear