Stutter or jerk at low throttle?

bigcanoe

Junior Member
Joined
Feb 19, 2012
Posts
8
Reaction score
2
Today I had a series of shudders or stumbles when driving the car. I was going about 45, up a hill, and I gave it slight gas. I am not sure of gear as it’s an automatic. It has 95k miles and is a 2008 GT convertible. No CEL was thrown and I just ordered a reader to check codes and do some real time monitoring. It did it again, similar, but less pronounced, again under low throttle later. The car had been driven about 15 minutes. I had come to a stop sign. Stopped, turn right onto a 45, going down a hill probably coasting, get to up hill, give very slight throttle to accelerate up hill and it happened. So I think I was coasting beforehand. Otherwise it’s driving fine.

Any ideas what to check or scan for?
 

RED09GT

Equal Opportunity Offender
S197 Team Member
Joined
Jul 17, 2009
Posts
2,630
Reaction score
488
Location
Kelowna, B.C. Canada
Did it downshift when you gave it gas?
The 5R auto has some issues with downshifting, especially out of 5th gear. Most code readers can't read transmission codes so I would watch for the basics like fuel pressure, spark, knock sensor activity, etc...
If nothing stands out, it is probably transmission related.
 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
3,880
Reaction score
1,751
Location
Cyprus
Cleaning the inside of the throttle body and cleaning the MAF sensor element might just solve your problem.
 

bigcanoe

Junior Member
Joined
Feb 19, 2012
Posts
8
Reaction score
2
Thank you! I will look into that. So far it seems like it could be anything: plugs, coils, fuel filter, MAF/TB, torque converter, transmission, etc.
 

Juice

forum member
Joined
Aug 24, 2017
Posts
4,622
Reaction score
1,904
If there arent any codes, it will likely be a tuneup related issue. Plugs, filters, etc.
However, I believe it will throw codes eventually as pending codes (no CEL yet) mature and set a fault (CEL comes on).
Hopefully, the reader you got can scan the pending codes. Not all readers can.
 

bigcanoe

Junior Member
Joined
Feb 19, 2012
Posts
8
Reaction score
2
Thanks! I got a bluetooth ELM one so I can do some live scans to my phone.
 

JJDAG

forum member
Joined
Oct 8, 2017
Posts
255
Reaction score
129
Location
Queensbury New York
If there’s no codes and nothing showing while monitoring always start with the simple things that won’t cost money for parts. Guessing most always leads to wasted money. When I worked for Ford I remember several cars with a similar issue almost never showed up while we had the car in the shop of count codes, eventually a coil would show bad, if that’s what it turns out to be just replace them all at the same time or you will go through this every couple months or less.
 

bigcanoe

Junior Member
Joined
Feb 19, 2012
Posts
8
Reaction score
2
Drove again today, nothing major. If I’m cruising along, speed doesn’t seem to matter and I give it medium throttle I feel a brief rumble behind me like the exhaust or trunk area. Then the power kicks in. Still no codes or pending codes on the OBD reader. I will attack the easy stuff then plugs and coils.
 

bigcanoe

Junior Member
Joined
Feb 19, 2012
Posts
8
Reaction score
2
I cleaned the MAF, the TB, and replaced the fuel filter myself. I paid to have the plugs replaced. They broke 3 following the TSB. I am glad to have that done and she is purring like a kitten now!
 

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Sponsor Links

Banner image
Back
Top