GMC Envoy (1998-2009) firing order — what is it?
Out of all the GMC SUV-class vehicles, the Envoy proved to be one of the most reliable options. It’s largely due to all the exceptional engine types including the Vortec V6 and the dependable 5.3-liter V8. Still, it’s up to each driver to keep the engine’s combustion cycle aligned and that’s where the GMC Envoy (1998-2009) firing order comes into play.
If you aren’t familiar with it, don’t worry – our team will break it all down for you as we go through the firing orders for different Envoy engines and cylinder arrangements to guide you.
| ENVOY YEARS | ENGINE | FIRING ORDER |
|---|---|---|
| 1st Gen (1998-2000) | 4.3L V6 | 1-6-5-4-3-2 |
| 2nd Gen (2002-2009) | 4.2L I6 | 1-2-3-4-5-6 |
| 5.3L V8 | 1-8-7-2-6-5-4-3 |
First-generation GMC Envoy (1998-2000) firing order
The first-gen Envoy model only featured one engine option and it was the Vortec 4.3-liter V6. It was the only optional engine for all the trims, so let’s see what the firing order looks like.
GMC Envoy 4.3L firing order
The GMC Envoy 4.3L firing order is 1-6-5-4-3-2 and this engine is a transverse V6. That means the engine is rotated within the engine bay, and unlike the regular V6 with the driver’s side and the passenger’s side bank, it has an upper and a lower bank.
So, the upper-side cylinders go in order 1, 3, and 5 from left to right, with the cylinders 2, 4, and 6 being in the lower bank, also ordered left to right.
Second-generation GMC Envoy (2002-2009) firing order
For the second-gen Envoy model, GMC added two new engine options, while the old Vortec V6 was removed from the lineup. So, we’ll focus on the new inline-six and V8 used in this model generation.
GMC Envoy 4.2L firing order
Unlike the older 4.3-liter V6, the 4.2L engine used in the second generation of the Envoy was a straight-six. That means it has a different firing order of 1-2-3-4-5-6, and the cylinder arrangement of the engine is different from the one in a V6.
The cylinders are ordered from the first one to the sixth one in a straight line, going from the first cylinder at the front of the engine to the back.
GMC Envoy 5.3L firing order
The GMC Envoy 5.3L firing order is 1-8-7-2-6-5-4-3 and this V8 is a longitudinal engine. So, the engine is divided into two cylinder banks, one with the odd cylinder numbers and one with the even cylinder numbers.
Driver’s side cylinders are laid out in order 1, 3, 5, and 7 front to rear, while the passenger’s side houses cylinders 2, 4, 6, and 8 also front to rear.
Our take
If you own a GMC Envoy with a six-cylinder or a V8, this guide hopefully settles some of your main dilemmas when it comes to engine maintenance. Our final piece of advice is to differentiate between the V6 and an inline-six engine, and you should be able to easily avoid and prevent misfires.
