A Real Puzzler: Car Stutters When Shifting Into OD Only When Warm

Hello and Thank You for checking out my thread.

In a nutshell I have an '06 Taurus that is pretty mint -108k miles - but the other day when driving home the car stuttered at about 40 mph, just as it was shifting into Overdrive. My heart sank because I was afraid my transmission was busted. Continued until I got home.

The next morning I took the car out cold and nothing, car shifted like it was fresh from the factory. I said Ok, but I noticed the rpm needle wasn’t steady with the tiniest fluctuation between 500 and 600 rpm while idle.

So, I go for a drive later and the car is driving and shifting well but there is a hum sound from the front passenger side of the rear of the engine compartment. The car is still driving and shifting well. Then, after driving enough to get the car up to temperature, the car stutters again at 40 mph and when shifting into Overdrive.

I’ve confirmed, over the past few days, the car runs perfectly when cold and the car only stutters when shifting into Overdrive when warm, as I can drive the car in low gear at any temperature all over town with no problems.

So there it is: Can anyone help me figure out why my 2006 Taurus SE (which I love dearly) stutters when shifting into Overdrive only when the engine is warm?

Ray in New Jersey

Have you had a transmission fluid and filter service?

More than likely, the problem is related to the overdrive lock-up mechanism. and this could be a case of a fairly simple external repair to the transmission.

I suggest that you take the car to an independent transmission shop, NOT to a chain-run operation such as Lee Myles, Cottman, or (God forbid) AAMCO. While it is at the indy trans shop, make sure that they also do a fluid and filter change if it has been more than 3 yrs/30k miles since the last trans fluid change.

What you’re describing is called torque converter clutch shudder.

The torque converter clutch doesn’t engage until the engine reaches operating temperature. This allows the engine to warm faster to reduce emissions.

One thing that can cause this is if the transmission fluid and filter hasn’t been serviced for a long time. The transmission fluid contains friction modifiers that allows the clutch to engage properly. If these friction modifiers break down due to wear it can cause clutch shudder.

If you can’t remember the last time the transmission fluid/filter were serviced, I’d start there.

If the clutch shudder still remains, then I’d add this to the transmission fluid.



OK. transmission fluid has not been changed. I did check the trans fluid the day this happened - the proper way - and the fluid looked clean (red) and smelled sweet.

I will schedule an appointment to have the fluid and filter changed tomorrow and update the outcome of the advice I’ve gotten so far.

Good stuff, guys. Thanks!

This is a pretty common complaint. Not just for Taurus’s but for many automatics. You might Google “Taurus torque converter shutter” and see if there’s something there, like a tsb or recall for your car for this symptom. Also take a look at Consumer Reports Reliability Guide, they list all the most common known problems by make/model/ year. My local Barnes and Noble bookstore had a big stack of this publication last time I was there.

I’m in agreement about a fluid and filter change. As a long time multiple Ford owner I’ve found them to be a bit finicky when the fluid starts getting some wear on it. The usual symptom is a torque converter shudder around 40 MPH or a very, very subtle shift flare when it goes into overdrive.

Sometimes the latter is erratic or barely even noticeable unless one is nit-picky; and I am. The best policy is a fluid/filter change every 30k miles; 40k at most.


I took the car to the transmission shop yesterday and the verdict was… not the torque converter… trans and all components are fine, or so they say.

They did find a misfire in cylinder 1 and attributed the shudder to that. I plan on doing a tune-up myself tomorrow, as I am reasonably mechanically inclined, and will update afterwards. If that doesn’t work, I’m thinking change the fuel filter and clean out the injectors.

For anyone who may search this thread in the future there is an easy to get to the back of a 3rd and 4th generation Ford Taurus engine, where the 1,2, and 3 plugs are. See video below…

A misfire is a misfire…Trans stutter is Trans stutter. I hope its option number one for you. Taurus trannys are WELL known for dying early…so. Lets stick to option one…should be quite obvious actually.


Ok, so to close this discussion. I got excellent advice but it did turn out to be a misfire in the #1 cylinder. Changed the plugs myself and car is back in good shape.

We’re glad you found this to be an easy and inexpensive fix.


Fantastic that it’s not a converter or transmission issue but I would advise a full transmission service anyway. That could prevent you from having to post back in the future about a balky transmission or one that did fail.

Thanks for taking the time to post the follow-up OP. Could you tell what was causing the misfire? Plug electrode caked w/gunk? Gap too wide?