Stutter when accelerating when warm?

Tiny
HEATHER LIDER
  • MEMBER
  • 2014 FORD EXPLORER
  • 3.7L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 176,000 MILES
I have the vehicle listed above Police Interceptor. A few weeks ago, I took it in for an oil change, it was driving perfectly fine prior. I left the shop and had to stop at a stop light immediately, when the light turned green my vehicle would not accelerate. Then at restart the engine stalled, a technician came out and was able to drive it back in. The check engine light came on, they fiddled with connectors etc, took it for a drive and noticed a stutter/driving hard. The next day an engine technician looked at it, there were no codes and no check engine light. The Mass Air Flow Sensor was not properly connected, they fixed that. Since leaving the shop I notice a lag/stutter when driving. It seems to drive fine when it is cold and before the engine warms up. Once the engine warms up, I can feel the stutter. It is noticeable when I am accelerating above 17MPH or 25MPH seems to vary. It is most noticeable when driving up a steep incline and creates a shuddering sensation. I do have codes for System Too Lean Bank 1 P0171 and Bank 2 P0174 and Catalyst System Efficiency Below Threshold Bank 2 code P0430. Prior to cleaning the MAF code P0420 Catalyst System Efficiency Below Threshold Bank 1. I replaced the MAF, that did not fix the issue. I am taking it to a different shop next week since the first said they couldn't find any problems however they cannot take a look at it until next week. I would appreciate any suggestions. Also, could I be causing more damage by driving to and from work each day?
Do you
have the same problem?
Yes
No
Thursday, September 29th, 2022 AT 11:37 AM

9 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

If this started after they worked on the vehicle and you have a lean fuel mixture on both banks, it sounds like they either left a vacuum hose off or the air box and inlet tube are not properly installed or tightened. Also, make sure they didn't bump any vacuum hoses or leave them disconnected.

Here is a link that explains how to check:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know what you find.

Joe

Was this
answer
helpful?
Yes
No
Thursday, September 29th, 2022 AT 7:05 PM
Tiny
HEATHER LIDER
  • MEMBER
Replacements that have been made Purge Valve sensor, all spark plugs and boots. They said the sparkplugs and boots were completely shot and were hopeful that would fix the issue. Even after those replacements the issue is still happening, only between 25-40MPH, there are no issues above or below that. The shop that has it currently is completely lost as to the cause of continued issues. There are no longer any catalyst codes and fuel trims look good. They suggested I go to the dealership. At this point I am around $1,000.00 in with still no answer.
Was this
answer
helpful?
Yes
No
Wednesday, October 5th, 2022 AT 12:42 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

Could the shutter be coming from the transmission? If you pay attention, is it happening in one gear and then going away once the transmission shifts?

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Wednesday, October 5th, 2022 AT 5:20 PM
Tiny
HEATHER LIDER
  • MEMBER
I just heard back from the third shop, which is our local Ford dealer, they are saying it is a bad torque converter. This is based off of a P0740 code. Their price to repair is $3,207.24 prior to any tax. I started calling around to get some other estimates which were way less than this one. The fourth shop I talked to, which is a transmission shop, said maybe it isn't the torque converter, maybe it is the clutch solenoid. I am going to take it to the transmission shop on Thursday so they can take it for a drive and hopefully they can narrow down the issue a little more.
Was this
answer
helpful?
Yes
No
Tuesday, October 11th, 2022 AT 1:37 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

That is correct. This can happen as the result of a faulty torque converter, or the torque converter clutch solenoid (TCC).

I would have them check it for you. If it is the torque converter, I would be happy to provide the directions for you to replace it. The part should be under $200.00.

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Tuesday, October 11th, 2022 AT 7:16 PM
Tiny
HEATHER LIDER
  • MEMBER
Well, I went on a rather length drive with someone who specializes in transmissions and it has him a bit stumped as well. There were several times during our drive that he would have expected it to feel and see problems on his diagnostic tool. The issue does not happen consistently enough for him to feel confident the problem is related to the torque converter. He said it feels like there are 2 different things going on. There is a wobble that can be felt above 60, which to him feels like a tire issue. He recommended new tires, which I was aware I needed; however I do not want to spend $1000+ on new tires before identifying the cause of the lag/slip and the cost of those repairs. After our 40min drive and discussion he suggested starting with checking the fluid levels next week. There were no current codes. I will let you know what I hear next week.
Was this
answer
helpful?
Yes
No
Friday, October 14th, 2022 AT 11:26 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

Thanks for the update, Heather. If you have a chance, let me know what you find. I'm interested in knowing.

Take care,

Joe
Was this
answer
helpful?
Yes
No
Friday, October 14th, 2022 AT 9:55 PM
Tiny
HEATHER LIDER
  • MEMBER
Update: Transmission fluid was around a quart and a half low. The shop put in an additive and topped up the fluid. They asked me to drive it around for a week or so and touch base with them again. I am still having some symptoms when the engine is warmed up and between the same speeds; it is worse after taking somewhat sharp left turns while accelerating (ex- our neighborhood has a tight roundabout). The sensation now feels more like a surge rather than a lag or drop out. It seems to have a consistent pattern when it does happen. I did leave a voicemail with the shop but haven't heard back yet.
Was this
answer
helpful?
Yes
No
Friday, October 28th, 2022 AT 1:16 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi Heather,

By chance, has the transmission ever been properly serviced with a new filter? Also, there could be a restriction in something like the cooler.

It's odd that it's worse when turning.

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Friday, October 28th, 2022 AT 10:01 PM

Please login or register to post a reply.

Sponsored links