Mild "bucking" under mild acceleration
Thread Starter
Rennlist Member
Joined: Dec 2009
Posts: 1,710
Likes: 332
From: Central Jersey
Could it be the engine mounts at the back of the engine carrier? If you remove the air box you can visually inspect them fairly easily. Even without removing the airbox you can get someone to gun the engine at idle while you watch with the deck lid open and see if it appears you are getting excessive play. The transmission also has mounts but I don't know how hard it is to inspect them.
This is all just a wild-*** guess in the absence of other suggestions, so sorry if it sends you on a wild goose hunt.
This is all just a wild-*** guess in the absence of other suggestions, so sorry if it sends you on a wild goose hunt.
Thread Starter
Rennlist Member
Joined: Dec 2009
Posts: 1,710
Likes: 332
From: Central Jersey
mileage ? everyday driver? old gas? any work done on the car lately ? was it raining that day ? put a pro scan tool on it .it sounds like a miss fire issue which can be caused by many problems ......fuel,ignition ,sensors etc. i would hold off on replacing the engine just yet lol
Gas: Less than a week old
No work done on car recently (or ever, pretty much!)
It was not raining.
Wouldn't one HEAR a misfire? Or might it at least throw a light on my dashboard?
Thread Starter
Rennlist Member
Joined: Dec 2009
Posts: 1,710
Likes: 332
From: Central Jersey
Mike,
I'm not sure what the final verdict was but they replaced my engine no questions asked in about 3 days.
Your problem sounds exactly like mine….exactly!
I would keep noticing this hesitation that came and went and it happened at speed (highway too) but not always and at all different speeds. They started by telling me it must be the gas but I knew that wasn't it. My tech took my car home for the weekend and told me he noticed that one side of the car was very sooty above the exhaust and there was some kind of a valve problem.
They replaced that engine immediately and the car only had 4,000 miles on it.
That's what happened to me Mike and it might not be at all what's going on with yours but see what they say. If you want to call me you can and I'll send you a PM with my number just let me know. I can probably get my tech to speak with you as well but I'm in Florida now n to NJ so I'd have to coordinate that.
I'm sure he'd remember exactly what it was.
Good Luck.
Tom
I'm not sure what the final verdict was but they replaced my engine no questions asked in about 3 days.
Your problem sounds exactly like mine….exactly!
I would keep noticing this hesitation that came and went and it happened at speed (highway too) but not always and at all different speeds. They started by telling me it must be the gas but I knew that wasn't it. My tech took my car home for the weekend and told me he noticed that one side of the car was very sooty above the exhaust and there was some kind of a valve problem.
They replaced that engine immediately and the car only had 4,000 miles on it.
That's what happened to me Mike and it might not be at all what's going on with yours but see what they say. If you want to call me you can and I'll send you a PM with my number just let me know. I can probably get my tech to speak with you as well but I'm in Florida now n to NJ so I'd have to coordinate that.
I'm sure he'd remember exactly what it was.
Good Luck.
Tom
Thread Starter
Rennlist Member
Joined: Dec 2009
Posts: 1,710
Likes: 332
From: Central Jersey
Got car back from my indy.
Short story is: keep driving and let him know if it happens again. No codes thrown, no smoke... basically no sign that it actually happened at all.
So the jury is still out.
Short story is: keep driving and let him know if it happens again. No codes thrown, no smoke... basically no sign that it actually happened at all.
So the jury is still out.
Drifting
Joined: Apr 2010
Posts: 3,112
Likes: 563
From: Naples, Florida
The same thing happened to me until my guy took the car home for the weekend.
It was very frustrating since the problem would never present itself when I brought it to the dealer.
Good Luck Mike!
Tom
It was very frustrating since the problem would never present itself when I brought it to the dealer.
Good Luck Mike!
Tom
Intermediate
Joined: May 2010
Posts: 39
Likes: 0
I'm having similar issues on my 06 C2S. It has 120k on it with original clutch. I'm leaning that direction since it didn't throw any codes and I would essentially lose all power, but RPM's would stay fairly constant.
Three Wheelin'
Joined: Feb 2006
Posts: 1,412
Likes: 4
When I first got my car 9.5 years and 40K miles ago I experienced this, 2007/8. There was some chat on the boards about this unidentified mysterious behavior so I was not alone. Bottom line: happened twice, never returned. I'm with tech, drive it and see what happens. Ghosts in the Machine and all that. Good luck.
Track Day
Joined: Nov 2016
Posts: 19
Likes: 0
From: Gilbert, Arizona
Old post but my 65K mile 997S did a stumble twice today. First time ever. Under light acceleration in 1st gear just fell on its face. Still running foot back into pedal and fine. No check engine light or anything unusual otherwise. I hate intermittent stuff as they will never happen when you want it to.
Track Day
Joined: Nov 2016
Posts: 19
Likes: 0
From: Gilbert, Arizona
Bad gas...could very well be. I think the gas in the tank is from early November. I have not been able to drive it much since then. Still has 1/2 tank too. Drove today and as normal so running that out and fill up soon. Thanks.
Nordschleife Master
Joined: Mar 2004
Posts: 8,386
Likes: 441
From: Southwest
Pro
Joined: Jun 2013
Posts: 665
Likes: 7
From: Canada, GTA
Old post but my 65K mile 997S did a stumble twice today. First time ever. Under light acceleration in 1st gear just fell on its face. Still running foot back into pedal and fine. No check engine light or anything unusual otherwise. I hate intermittent stuff as they will never happen when you want it to.
I call it hesitating, sputtering.
https://rennlist.com/forums/997-foru...e-floored.html