Engine hesitation 2-3k rpm
Thread Starter
Rennlist Member
Joined: Apr 2014
Posts: 599
Likes: 2
From: Sussex, UK
Engine hesitation 2-3k rpm
Just looking for some advice from others who have experienced the same...
2014 C4S with 1400 miles on the clock. From day 1 the engine has had a definite hesitation (evidenced by feel, sound and revs) in the 2-3k rpm range. It is completely clear of any hesitation below 2k and above 3k rpm. It seems to be getting better with break in but is still there at 1400 miles. It also seems to coincide with a mechanical resonance in the engine when blipping the throttle at standstill (i.e slowly increasing the revs in neutral while stationary the engine goes from silky smooth to a mode of modest vibration through this range then back to silky smooth on the other side)
It's not debilitating in any way and is quite subtle whilst driving but is the only thing I've noted on an otherwise faultless and dreamy experience..
Just looking for advice - is this something which will abate with usage, a characteristic of the engine, or needs rectifying at the OPC?
Thanks!
2014 C4S with 1400 miles on the clock. From day 1 the engine has had a definite hesitation (evidenced by feel, sound and revs) in the 2-3k rpm range. It is completely clear of any hesitation below 2k and above 3k rpm. It seems to be getting better with break in but is still there at 1400 miles. It also seems to coincide with a mechanical resonance in the engine when blipping the throttle at standstill (i.e slowly increasing the revs in neutral while stationary the engine goes from silky smooth to a mode of modest vibration through this range then back to silky smooth on the other side)
It's not debilitating in any way and is quite subtle whilst driving but is the only thing I've noted on an otherwise faultless and dreamy experience..
Just looking for advice - is this something which will abate with usage, a characteristic of the engine, or needs rectifying at the OPC?
Thanks!
Burning Brakes
Joined: Jan 2009
Posts: 843
Likes: 20
From: Northern VA
I have this issue. I am at 6500 miles. I have taken it to the dealer for this three times. The engine management software has been updated, but the issue remains. Several on this forum will just tell you to drive the engine hard and it'll be fixed. Not yet for me...
I have two distinct hesitation modes - one at lower throttle through the 2-3K RPM range, and one slightly larger stumble right at 3K RPM. The latter is most likely related to the variable cam adjusting once it passes through 3K RPM. Still trying to figure out the other.
I would just say be careful about asking about this on this forum :-). The threads have been interesting.
I have two distinct hesitation modes - one at lower throttle through the 2-3K RPM range, and one slightly larger stumble right at 3K RPM. The latter is most likely related to the variable cam adjusting once it passes through 3K RPM. Still trying to figure out the other.
I would just say be careful about asking about this on this forum :-). The threads have been interesting.
Banned
Joined: Jan 2013
Posts: 26,140
Likes: 5,466
From: Chicagoland Area
Banned
Joined: Jan 2013
Posts: 26,140
Likes: 5,466
From: Chicagoland Area
Thread Starter
Rennlist Member
Joined: Apr 2014
Posts: 599
Likes: 2
From: Sussex, UK
Thanks Lexvan, Stealthboy and Mondrian.
I use it as a daily driver (about 500 miles per week) but a lot of my mileage so far has been motorway so i do go through the 2-3k range frequently. As I get nearer to the 2000 mile mark I'm starting to do some more spirited driving and taking lots of country road excursions (and i have to say... I'm having a blast... Even below 5krpm)
I even notice it with the ACC turned on when the car in front pulls away and the ACC auto-accelerates to the predefined speed without me intervening... You can visually see the tachometer hesitating several times as it goes up through the range.
I will be meeting the redline in a couple of weeks and endeavour to find out all the new audio-velocity-acceleration pleasure that brings. Hopefully it will clear itself otherwise I'll pop into the porsche OPC to ask about it.
Thanks for sending the link Lexvan (and thanks for the health warning Stealthboy!). I will read & digest.
As i said, i am in love with this car and it doesn't detract from that. I just want to know if it is all working 'normally'
Thanks Again - much appreciated
I use it as a daily driver (about 500 miles per week) but a lot of my mileage so far has been motorway so i do go through the 2-3k range frequently. As I get nearer to the 2000 mile mark I'm starting to do some more spirited driving and taking lots of country road excursions (and i have to say... I'm having a blast... Even below 5krpm)
I even notice it with the ACC turned on when the car in front pulls away and the ACC auto-accelerates to the predefined speed without me intervening... You can visually see the tachometer hesitating several times as it goes up through the range.
I will be meeting the redline in a couple of weeks and endeavour to find out all the new audio-velocity-acceleration pleasure that brings. Hopefully it will clear itself otherwise I'll pop into the porsche OPC to ask about it.
Thanks for sending the link Lexvan (and thanks for the health warning Stealthboy!). I will read & digest.
As i said, i am in love with this car and it doesn't detract from that. I just want to know if it is all working 'normally'
Thanks Again - much appreciated
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Pro
Joined: Jan 2013
Posts: 571
Likes: 85
From: SoCal
Sounds like the dreaded VarioCam stumble. For some reason, on some but not all cars, the cam profile changeover is less than smooth. The VarioCam system is very complex, with numerous mechanical and electrical events taking place in a very short time period. Fairly sure it's not ignition related because it only appears at specific rpm's under light load. I think a bad coil would show up under higher revs/load.
Not a huge concern overall, but once you detect it you can feel it almost every time you accelerate under light throttle.
Not a huge concern overall, but once you detect it you can feel it almost every time you accelerate under light throttle.
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Burning Brakes
Joined: May 2006
Posts: 889
Likes: 6
From: Ontario,Canada
I had that problem last year before the car went into storage for six months. I have not noticed the hesitation since the car had its' first annual service. I do not know if the dealer downloaded new software but the hesitation is gone for now. My car has 5,600 kms(3,400mi).
Thread Starter
Rennlist Member
Joined: Apr 2014
Posts: 599
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From: Sussex, UK
A light update....
About 6 weeks ago, my previously 'notable but not impeding' stumble between 2-3krpm suddenly got quite significantly worse (@11k miles)... It had become a detractor... I worried about the 'irreversible' nature of this reported by many... and the severe remedial action taken by Matt started to resonate in my mind...
I tried the 60 second ignition trick and drove hard for a while ... but no improvement.... Then, I left the car in a lock-up for 10 days over the Christmas & New Year period whilst we took a vacation... This is the longest stretch without driving since new.... and hey presto... stumble has almost disappeared! Yes it's still there if I look really hard for it but it is back to the benign almost negligible nature of old... The difference is far beyond placebo effect... I am happy and surprised and very conscious it may come back... But you can't wipe the smile off my face right now...
So what did leaving it for 10 days do? I didn't remove the power or do anything special... Just locked it and walked away... This adds weight to it being a setting/algorithm/software issue... Rather than mechanical... But why would it reset?
This is where I hand over to anyone with science and reason rather than authority .....
About 6 weeks ago, my previously 'notable but not impeding' stumble between 2-3krpm suddenly got quite significantly worse (@11k miles)... It had become a detractor... I worried about the 'irreversible' nature of this reported by many... and the severe remedial action taken by Matt started to resonate in my mind...
I tried the 60 second ignition trick and drove hard for a while ... but no improvement.... Then, I left the car in a lock-up for 10 days over the Christmas & New Year period whilst we took a vacation... This is the longest stretch without driving since new.... and hey presto... stumble has almost disappeared! Yes it's still there if I look really hard for it but it is back to the benign almost negligible nature of old... The difference is far beyond placebo effect... I am happy and surprised and very conscious it may come back... But you can't wipe the smile off my face right now...
So what did leaving it for 10 days do? I didn't remove the power or do anything special... Just locked it and walked away... This adds weight to it being a setting/algorithm/software issue... Rather than mechanical... But why would it reset?
This is where I hand over to anyone with science and reason rather than authority .....
Pro
Joined: Jan 2013
Posts: 571
Likes: 85
From: SoCal
A light update....
About 6 weeks ago, my previously 'notable but not impeding' stumble between 2-3krpm suddenly got quite significantly worse (@11k miles)... It had become a detractor... I worried about the 'irreversible' nature of this reported by many... and the severe remedial action taken by Matt started to resonate in my mind...
I tried the 60 second ignition trick and drove hard for a while ... but no improvement.... Then, I left the car in a lock-up for 10 days over the Christmas & New Year period whilst we took a vacation... This is the longest stretch without driving since new.... and hey presto... stumble has almost disappeared! Yes it's still there if I look really hard for it but it is back to the benign almost negligible nature of old... The difference is far beyond placebo effect... I am happy and surprised and very conscious it may come back... But you can't wipe the smile off my face right now...
So what did leaving it for 10 days do? I didn't remove the power or do anything special... Just locked it and walked away... This adds weight to it being a setting/algorithm/software issue... Rather than mechanical... But why would it reset?
This is where I hand over to anyone with science and reason rather than authority .....
About 6 weeks ago, my previously 'notable but not impeding' stumble between 2-3krpm suddenly got quite significantly worse (@11k miles)... It had become a detractor... I worried about the 'irreversible' nature of this reported by many... and the severe remedial action taken by Matt started to resonate in my mind...
I tried the 60 second ignition trick and drove hard for a while ... but no improvement.... Then, I left the car in a lock-up for 10 days over the Christmas & New Year period whilst we took a vacation... This is the longest stretch without driving since new.... and hey presto... stumble has almost disappeared! Yes it's still there if I look really hard for it but it is back to the benign almost negligible nature of old... The difference is far beyond placebo effect... I am happy and surprised and very conscious it may come back... But you can't wipe the smile off my face right now...
So what did leaving it for 10 days do? I didn't remove the power or do anything special... Just locked it and walked away... This adds weight to it being a setting/algorithm/software issue... Rather than mechanical... But why would it reset?
This is where I hand over to anyone with science and reason rather than authority .....
Seriously, glad yours is somewhat better, and hoping that someone solves this mystery before too much longer.
Rennlist Member
Joined: Oct 2002
Posts: 26,145
Likes: 3,908
From: S.F Bay Area
Rennlist Member
Joined: Oct 2002
Posts: 26,145
Likes: 3,908
From: S.F Bay Area
A light update....
About 6 weeks ago, my previously 'notable but not impeding' stumble between 2-3krpm suddenly got quite significantly worse (@11k miles)... It had become a detractor... I worried about the 'irreversible' nature of this reported by many... and the severe remedial action taken by Matt started to resonate in my mind...
I tried the 60 second ignition trick and drove hard for a while ... but no improvement.... Then, I left the car in a lock-up for 10 days over the Christmas & New Year period whilst we took a vacation... This is the longest stretch without driving since new.... and hey presto... stumble has almost disappeared! Yes it's still there if I look really hard for it but it is back to the benign almost negligible nature of old... The difference is far beyond placebo effect... I am happy and surprised and very conscious it may come back... But you can't wipe the smile off my face right now...
So what did leaving it for 10 days do? I didn't remove the power or do anything special... Just locked it and walked away... This adds weight to it being a setting/algorithm/software issue... Rather than mechanical... But why would it reset?
This is where I hand over to anyone with science and reason rather than authority .....
About 6 weeks ago, my previously 'notable but not impeding' stumble between 2-3krpm suddenly got quite significantly worse (@11k miles)... It had become a detractor... I worried about the 'irreversible' nature of this reported by many... and the severe remedial action taken by Matt started to resonate in my mind...
I tried the 60 second ignition trick and drove hard for a while ... but no improvement.... Then, I left the car in a lock-up for 10 days over the Christmas & New Year period whilst we took a vacation... This is the longest stretch without driving since new.... and hey presto... stumble has almost disappeared! Yes it's still there if I look really hard for it but it is back to the benign almost negligible nature of old... The difference is far beyond placebo effect... I am happy and surprised and very conscious it may come back... But you can't wipe the smile off my face right now...
So what did leaving it for 10 days do? I didn't remove the power or do anything special... Just locked it and walked away... This adds weight to it being a setting/algorithm/software issue... Rather than mechanical... But why would it reset?
This is where I hand over to anyone with science and reason rather than authority .....
