Possible problem accelerating through 4000rpm, anyone else?

[mantis]

I recently noticed that when I am accelerating through ~3800-4200rpms the engine revs up a few 100 rpms and then "catches" back up. I'm not a gearhead but it feels the same as when I first got me elise and tried to accelerate fast from stop. I over-rev'd the car, dropped it into first, and it seemed like the car didn't want to go until the transmission finally caught up to the rpms (if that makes sense to anyone). I have 35k on the car and have had the car for about 3 years and a few weeks. The closest dealer is 100 miles away. Not sure if this falls under warranty work (or if the dealer will even honor my warranty now since I am a few weeks over the 3-year point). Some other info:

1) The weather has been around 40 degrees when this has happened (3 times)
2) The car was driven primarily in n San Antonio, Texas for the 3 years I have had it (hot weather)
3) I have only driven the car a few times since it has gotten cold here in the DC area (I plan to drive it around today to see if I just need to let the car warm up more)
4) I am due for an oil change
5) I don't think the dealer has ever replaced my transmission fluid (I never requested it)
6) Car seems a little louder (exhaust) now on acceleration. My daily driver is a jeep grand cherokee that is considerably quieter. This could be why the elise seems louder now.

Any help would be appreciated

[IXLR8]

Sounds like your clutch is slipping.
Any unusual smells with this?

[mantis]

No smells. Is there anything I can do to confirm? I'm thinking I should just bring it in and hope for the best. Thanks.

[Bavarian Motorist]

+1 on clutch



And sadly, they will not honor your expired warranty, especially on a wear-item like a clutch

[...m...]

...i don't know if its the same phenomenon you're describing, but when i first drive on a cold engine, i notice a conspicuous power dip somewhere in the low RPM band - i'll take note of the range tomorrow morning...my clutch is definitely not slipping...

...i'm in san antonio also, by the way, and i've only noticed it since temperatures have dropped over the past month or two...

[mantis]

Supposedly 60 degree weather in the DC area tomorrow. I might drive it to work and see how it performs in warmer weather. The thing is, it is parked in my building underground (around 60 degrees). I'm leaning towards the clutch thing. I'll have to check around on the site to see how much a clutch job costs. I'm sure it will be pretty expensive in this area.

[Bavarian Motorist]

Originally Posted by ...m...

...i don't know if its the same phenomenon you're describing, but when i first drive on a cold engine, i notice a conspicuous power dip somewhere in the low RPM band - i'll take note of the range tomorrow morning...my clutch is definitely not slipping...

...i'm in san antonio also, by the way, and i've only noticed it since temperatures have dropped over the past month or two...

I think the OP is describing the engine revs climbing but the speed not climbing (ie, the power not being delivered), then all of a sudden the power is delivered, hence the "catching up" description, which is what a slipping clutch feels like (mine was doing this a bit recently. decided to replace)


What you're describing sounds a bit different?

[...m...]

...might be - it almost reads more like synchro operation to me, but it surely could be a slipping clutch...tonight i tried to quantify the cold-engine power dip; i think it lies somewhere between 1500 and 3000 RPM, then slowly ramps back up through 4500 RPM or so, but it's a subtle thing...