# Misfire 2005 GMC Envoy XL cylinder 5

**URL:** <https://community.cartalk.com/t/misfire-2005-gmc-envoy-xl-cylinder-5/113559>\
**Category:** Maintenance/Repairs\
**Created:** [March 12, 2018, 3:16pm UTC](https://community.cartalk.com/t/misfire-2005-gmc-envoy-xl-cylinder-5/113559 "2018-03-12T15:16:22Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![TheoAustin](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@TheoAustin](https://community.cartalk.com/u/TheoAustin)\
**Post date:** [March 12, 2018, 3:16pm UTC](https://community.cartalk.com/t/misfire-2005-gmc-envoy-xl-cylinder-5/113559/1 "2018-03-12T15:16:22Z")

</div>

cylinder 5 missfire low compression

---

<div class="post-metadata">

**Author:** ![oldtimer-11](https://avatars.discourse-cdn.com/v4/letter/o/e79b87/32.png) [@oldtimer-11](https://community.cartalk.com/u/oldtimer-11)\
**Post date:** [March 12, 2018, 8:11pm UTC](https://community.cartalk.com/t/misfire-2005-gmc-envoy-xl-cylinder-5/113559/2 "2018-03-12T20:11:13Z")

</div>

Rings or Valves with valves more likely. Have a wet and dry compression test done. If the wet compression is a lot higher, it is the rings.

---

<div class="post-metadata">

**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\
**Post date:** [March 13, 2018, 1:35am UTC](https://community.cartalk.com/t/misfire-2005-gmc-envoy-xl-cylinder-5/113559/3 "2018-03-13T01:35:07Z")

</div>

So I looked up the specs . . .

For the 4.2 liter straight 6, which I assume you have, it’s 215psi.

Just how low is the compression?

Without even being there, my gut feeling is valve train

I also suggest a cylinder leakdown test. I suspect you’ll have quite significant leakage, and it’ll be from the intake valves.