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I have a 2004 Honda Accord sedan, automatic transmission with about 180k. I wanted to get a second opinion on what I'm observing to see if there's a problem (which I think might be starting) or if there's nothing to worry about.

Yesterday while driving on the freeway up a mountain (posted speed is 55MPH and I was going about 60MPH but slowing down due to the mountain), I let up on the gas b/c someone signaled to get into my lane. After they merged in, I pressed the gas to keep my current speed. However, the engine acted like it was switched to neutral, in that when I pressed on the gas, the engine revved but it didn't go anywhere. I let go and pressed again, and this time, I felt my car get pulled by the engine. I don't think I pressed the pedal that hard the first time so I don't know why it revved high, other than my transmission is starting to have problems.

The second incident occurred about 1 wk ago while driving down an expressway (posted speed is 45-50MPH but there are traffic lights). I was going about 35-40MPH. Traffic started to open up a little so I was accelerating up to 50MPH. However, it seemed like the car didn't switch gears. I could hear it rev high but I think the car was still being pulled by the engine/moving. I let go of the gas and pressed again and this time, it seemed like the gear switched in that it didn't rev high.

I don't consider myself an aggressive driver (no jack rabbit starts, no flooring the gas pedal, no hard braking, etc.) and I don't remember these things happening before so when it happens while driving, it's a little scary.

Are these 2 events an indication of my transmission starting to go out or am I just being an alarmist?

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    What model is your car (Civic or Accord)? Has the car ever had transmissions work done on it in the past? Have you heard of this recall for 1999-2004 Honda transmissions? Have you checked the transmission fluid in your car? What color is it (red or brown)? How does it smell? – Pᴀᴜʟsᴛᴇʀ2 Aug 24 '15 at 21:12
  • @Paulster2, it's an Accord but no transmission work has been done on it in the past and I didn't receive any recall notices in the mail, nor have I been reminded by the dealer that there are outstanding recalls on my vehicle when I bring it in for servicing. I didn't check the fluid (didn't think to) but I don't smell any burning when I park/stop my car. I'll try to smell it later when i check the fluid. Someone told me if it smells like roasted peanuts, I'm in trouble. – Classified Aug 24 '15 at 22:28
  • You won't smell anything when parking (unless it's really bad). You'll recognize a burnt smell very easily if there is an issue ... I don't think I've ever thought it smelled like burnt peanuts, though. Just pull the dip stick and take a whiff. Also check to ensure there is enough fluid in it. – Pᴀᴜʟsᴛᴇʀ2 Aug 25 '15 at 0:42
  • @Paulster2, can I check the fluid when the engine is cold? I don't want to burn myself when reaching in. If I need to check when the engine is warm, can I just drive around the block once or twice and check so the engine doesn't get TOO hot? – Classified Aug 26 '15 at 23:08
  • Absolutely. You cannot check the level, but you can check the fluid itself. – Pᴀᴜʟsᴛᴇʀ2 Aug 26 '15 at 23:09
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To me that sounds like your torque converter unlocking but your transmission not downshifting. Automatic transmissions have a torque converter in place of a clutch. The way that the torque converter works is by using turbines and stators which get spun using the transmission fluid. This process creates an enormous amount of heat and has the effect of making the engine rev at higher rpm's (not necessarily a bad thing).

To improve MPG's and also to reduce heat, the torque converter will lock up (i.e. make a physical mechanical coupling instead of a fluid coupling) which has the effect of reducing engine rpm's and reducing heat.

The transmission knows when it needs to upshift or downshift and before either happens, the torque converter will unlock (which will cause higher engine RPM's) and then lock back up again once the shift happens. There are times when it will stay unlocked for longer periods of time depending on the need.

If there is an issue with your car making a downshift, that would explain the higher RPM's and lack of power. Pushing the gas pedal enough will unlock the converter and letting off will lock it back up again.

What I recommend is that you do a full transmission fluid flush and examine the fluid for clutch material (blackish sand type of consistency). Also be sure to replace your transmission filter. If you cannot do this yourself, go to a shop! I would also have them check your vacuum modulators (or which ever device is used to control the shifts). Sometimes these get too hot and melt or the lines get holes in them which prevents accurate shifting. If it uses a TV cable, then readjust the cable on the linkage or replace it as it may have stretched and cannot depress the TV plunger all the way.

It doesn't sound like you have a slippage, but then again you might not have added all the details. If your transmission is slipping you would feel the engine rev but not go anywhere or the car would start to buck as the clutches slip and catch, slip and catch. You would notice this when starting off from a stop light though or any time you mash the gas pedal (high engine RPM's).

Be sure to change your transmission fluid (15k-20k) and check the levels regularly (every oil change, do this while the car is warmed up and running). It's also important that you use the CORRECT fluid type as they are not all made the same. Various types and levels of friction modifiers are used/required by different transmissions.

Edit: A quick way to see what might be going on is to smell your fluid. Fluid should be red or pinkish and have a sweet smell to it. If it's brown and/or has a nasty smell than you have internal issues that need to be addressed.

  • thx for the extra info. I HOPE I'm not leaving anything out of my description :-) but on flat ground, I don't feel any loss of power (knock on wood). I'll check when's the last time the transmission fluid was changed. I'll also let you guys know how it looks/smells when I check. I don't trust myself with taking a car apart so I'll have to let a garage do the flush the next time I'm in. The most advanced thing I've done is look down my HVAC system for items dropped thru the front vents. =) – Classified Aug 26 '15 at 23:07
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Transmission slip is usually due to low transmission fluid. DON'T let it keep slipping, that will ruin the transmission.

protected by Pᴀᴜʟsᴛᴇʀ2 Jul 29 '18 at 11:36

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