My father called me today to ask me about an RPM issue on my stepsisters' 01 and 03 V6 coupe's. When driving, say in 3rd gear, getting up to speed gradually, not excessively, shift at about 2500 RPM, the RPM's actually go up 100 or so after the clutch is engaged. It then takes several seconds for the RPM's to drop enough to be where they should be for the next gear.

He is concerned that just shifting into gear makes the clutch bog the car down to the correct RPM, potentially causing premature failure. Is this standard on this motor / trans combo (I know nothing about the SN95 platform)? Kind of weird that this is happening on both vehicles. Both are fairly new to the family. He test drove a Firebird for one of them previously ( ) and stated that the RPM's and shifting behavior was normal and as expected on that car.

I appreciate any help and feedback you can give me here!

Sean

 

Sounds to me like they're just keeping their foot on the gas a little too long when engaging the clutch, causing the revs to increase slightly.

In terms of the revs not dropping quickly: I had a 2000 V6 before this mustang, and if I remember right it pretty much did the same thing as what you're describing in terms of the revs not drastically dropping. But, my 05 doesn't seem much different either

But, I will say this: I've driven a new Carrera S, and relative to the mustang, the rev drop on the Porsche seemed HUGE once you pushed the clutch in. In fact, the revs dropped below where they would be once in the next gear. So, it might just be an "it's all relative" thing.

I really don't understand why this would be a problem though. You're always going from a higher rpm to a lower rpm when accelerating...that's the point of upshifting.

 

Not an issue of leaving the gas in when pushing in the clutch, this is my father driving, not my step sisters (no offense to step sisters out there ). I agree that the RPM's dropping shouldn't be an issue, that is the problem. Push in the clutch, RPM's go up, stay there...THEN drop. So if you are just tooling along and shifting without waiting, you let out the clutch and the engine has to bog down to match the RPM's for the gear you are now in, instead of the RPM's already being there.

 

I had a similar problem on a S-10 I had. Push in the clutch, rpm's rise and stay there for a few seconds. When you lifted off the gas, the TB didn't close all the way because the cruise control cable was out of adjustment and was holding it open just slightly. But it didn't always do it either so it was hard to diagnose at first.
Id check the return spring on the TB. May not be pulling it closed all the way. I also check the TPS and see if its operating correctly via voltage check throughout its range of movement.

On the Civic I have, the revs tend to hang for a moment after lifting off the gas but it has electronic throttle(like the S197), and its programmed to do this for emissions purposes. Supposedly it keeps from having a momentarily rich mixture from escaping the cylinders when closing the throttle. What a joke.

 

rotating mass on ford's 3.8 V6 is much larger and then the rotating mass the the 3.6 boxer 6 of Porche. not to mention the Porche pistons fire right at each other instead of wobbling diagonally in the V6.

Remember also that the 01 V6 based at $17K, barely out of the entry level vehicle price range. the tune and injection are hardly performance level. My v6 commuter does the same thing. Wouldn't be a problem if ford switches to a smaller displacement quad valve engine (less rotating mass).