# Slipping at constant speed

**URL:** <https://community.cartalk.com/t/slipping-at-constant-speed/41855>\
**Category:** Maintenance/Repairs\
**Tags:** mercury, sable\
**Created:** [January 4, 2010, 7:25pm UTC](https://community.cartalk.com/t/slipping-at-constant-speed/41855 "2010-01-04T19:25:59Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![bisstess](https://avatars.discourse-cdn.com/v4/letter/b/8dc957/32.png) [@bisstess](https://community.cartalk.com/u/bisstess)\
**Post date:** [January 4, 2010, 7:25pm UTC](https://community.cartalk.com/t/slipping-at-constant-speed/41855/1 "2010-01-04T19:25:59Z")

</div>

2003 Mercury Sable Wagon, 120,000 miles, mostly highway. While maintaining a constant highway speed, every once in a while the transmission feels like it slips. This only lasts for a second or two. Transmission fluid just changes at 100,000 miles/6 mos ago. Does anyone have any suggestions as to what I should start looking for to diagnose?

---

<div class="post-metadata">

**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\
**Post date:** [January 5, 2010, 12:38am UTC](https://community.cartalk.com/t/slipping-at-constant-speed/41855/2 "2010-01-05T00:38:47Z")

</div>

Was that the first change? the one at 100,000 miles?

---

<div class="post-metadata">

**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\
**Post date:** [January 5, 2010, 1:08am UTC](https://community.cartalk.com/t/slipping-at-constant-speed/41855/3 "2010-01-05T01:08:38Z")

</div>

What’s the tachometer doing when this happens? Does it go up? If not, it may be a slight engine misfire and not a transmission problem. Did you change your plugs at 100K miles?

---

<div class="post-metadata">

**Author:** ![bisstess](https://avatars.discourse-cdn.com/v4/letter/b/8dc957/32.png) [@bisstess](https://community.cartalk.com/u/bisstess)\
**Post date:** [January 5, 2010, 2:01am UTC](https://community.cartalk.com/t/slipping-at-constant-speed/41855/4 "2010-01-05T02:01:30Z")

</div>

Sorry, first change was at 50,000

---

<div class="post-metadata">

**Author:** ![bisstess](https://avatars.discourse-cdn.com/v4/letter/b/8dc957/32.png) [@bisstess](https://community.cartalk.com/u/bisstess)\
**Post date:** [January 5, 2010, 2:03am UTC](https://community.cartalk.com/t/slipping-at-constant-speed/41855/5 "2010-01-05T02:03:06Z")

</div>

I did not notice any change, will have to pay more attention. Yes, plugs were changed at 100,000 miles