New member here, proud owner of an '05 Envoy SLE 2WD. Bought it in February with 56,000 miles on the clock as a daily driver, and I promised myself I wouldn't do anything other than routine maintenance because I already have a project car - now I've got a huge list of upgrades waiting to be done. 
Long story short, I really liked the truck to begin with, now I'm in love. 
The day I picked her up, I did the following:
- Spark plugs: factory ACDelco/NGK's were shot and replaced with Autolite APP-5263 Double Platinums.
- COP boots: Denso 671-6069, which I was pretty impressed with quality wise. They came with springs as well, so I just replaced them, coated them with dialectic grease and put them on.
- Serpentine belt: another factory part. Replaced it with a Goodyear Gatorback 4060915 (150 amp alternator)
- Air filter: appeared this hadn't been replaced in quite a while. Went with an ACDelco A2014-C
- ATF, filter and gasket: Fluid was original. Went with ACDelco Dexron-VI and a GM 24208576 (deep pan) gasket kit.
- Thermostat: gauge would only go up a quarter of the way and there was a code stored. Replaced with an ACDelco 15-11006.
- Rear axle lube: went with GM 12378261 75W-90 synthetic and replaced the reuseable gasket whilst I was at it. Didn't look too bad, but would rather replace it.
- Power steering fluid: Genuine GM 89021184 power steering fluid. Steering feels better now after I flushed it out.
- Coolant: 50/50 mix of ACDelco Dex-Cool. Original coolant was still in the system and looked sparkling clean once the thermostat housing was removed. Thoroughly flushed out the system.
- Engine oil: the export owner's manual states anything from 0W-30 to 20W-50 can be used, I personally prefer using a 0W-40 or 5W-40 meeting Mercedes Sheet 229.5 spec. It gets a steady diet of either Mobil 1 0W-40 or Pennzoil Ultra Euro 5W-40, depending on availability, with a Purolator PureONE PL25288 filter.
- Tires: Pirelli Scorpion Verde 255/60-17 106V tires. This is an export size versus 245/65-17 domestic.
- Brakes: Bendix CT-3 pads front and rear with DOT 4 brake fluid
Also got a set of 6 Bosch flow-matched factory injectors:
Considering how well matched they are, I also indexed the plugs. They also have stainless steel basket filters (20 microns) to replace the factory plastic ones:
So far, the truck is as smooth as butter and I'm loving the performance/acceleration for what it is. It's got a knock sensor, so I'm running 98 RON (93 AKI) in it. Fuel economy's been pretty good, I've averaged 23 MPG with the 3.73 rear axle so far (mostly highway with cruise engaged). Oil changes based on the OLM are about 9,750 miles on average.
On the downside - build quality, as with other GMs in the family, left something to be desired.The plastic trim on the driver's seat that houses the seat control was snapped off when I bought it. I got a new one, which I will attempt to modify in some way to strengthen the support. I'm on the lookout for a leather wrapped center control lid from a Rainier to replace the one I have (softened in the middle). I'm not complaining though. No squeaks or cracks, etc. which is good news!
Other than that, I've got a ScanGauge-II on the way. I got a Gentex rearview with outside temperature display/compass on the way as well, once I wired up the OTS, it's good to go! I'm planning an instrument cluster/steering wheel/clockspring upgrade for the DIS and doing the e-Fan conversion - reading up on that at the moment (looking at something with a min 4000 cfm). I'm also considering upgrading the rear end to a 4.10, which I will be looking into, and getting a performance tune on a new PCM (keeping the original untouched in case I need to revert back to stock at any point). Looking at getting Ascender taillights as well, and debadging, tinting. Due to the nature of my job, I've got Whelen Vertex LEDs, along with some other emergency equipment, going on as well (half way through the installation). I'm also looking at the possibility of a column shift conversion with a foot operated parking brake, and doing something about the gap between the headlights/grille and the front bumper.
I plan on keeping her for a long, long time.
Long story short, I really liked the truck to begin with, now I'm in love.
The day I picked her up, I did the following:
- Spark plugs: factory ACDelco/NGK's were shot and replaced with Autolite APP-5263 Double Platinums.
- COP boots: Denso 671-6069, which I was pretty impressed with quality wise. They came with springs as well, so I just replaced them, coated them with dialectic grease and put them on.
- Serpentine belt: another factory part. Replaced it with a Goodyear Gatorback 4060915 (150 amp alternator)
- Air filter: appeared this hadn't been replaced in quite a while. Went with an ACDelco A2014-C
- ATF, filter and gasket: Fluid was original. Went with ACDelco Dexron-VI and a GM 24208576 (deep pan) gasket kit.
- Thermostat: gauge would only go up a quarter of the way and there was a code stored. Replaced with an ACDelco 15-11006.
- Rear axle lube: went with GM 12378261 75W-90 synthetic and replaced the reuseable gasket whilst I was at it. Didn't look too bad, but would rather replace it.
- Power steering fluid: Genuine GM 89021184 power steering fluid. Steering feels better now after I flushed it out.
- Coolant: 50/50 mix of ACDelco Dex-Cool. Original coolant was still in the system and looked sparkling clean once the thermostat housing was removed. Thoroughly flushed out the system.
- Engine oil: the export owner's manual states anything from 0W-30 to 20W-50 can be used, I personally prefer using a 0W-40 or 5W-40 meeting Mercedes Sheet 229.5 spec. It gets a steady diet of either Mobil 1 0W-40 or Pennzoil Ultra Euro 5W-40, depending on availability, with a Purolator PureONE PL25288 filter.
- Tires: Pirelli Scorpion Verde 255/60-17 106V tires. This is an export size versus 245/65-17 domestic.
- Brakes: Bendix CT-3 pads front and rear with DOT 4 brake fluid
Also got a set of 6 Bosch flow-matched factory injectors:
Considering how well matched they are, I also indexed the plugs. They also have stainless steel basket filters (20 microns) to replace the factory plastic ones:
So far, the truck is as smooth as butter and I'm loving the performance/acceleration for what it is. It's got a knock sensor, so I'm running 98 RON (93 AKI) in it. Fuel economy's been pretty good, I've averaged 23 MPG with the 3.73 rear axle so far (mostly highway with cruise engaged). Oil changes based on the OLM are about 9,750 miles on average.
On the downside - build quality, as with other GMs in the family, left something to be desired.The plastic trim on the driver's seat that houses the seat control was snapped off when I bought it. I got a new one, which I will attempt to modify in some way to strengthen the support. I'm on the lookout for a leather wrapped center control lid from a Rainier to replace the one I have (softened in the middle). I'm not complaining though. No squeaks or cracks, etc. which is good news!
Other than that, I've got a ScanGauge-II on the way. I got a Gentex rearview with outside temperature display/compass on the way as well, once I wired up the OTS, it's good to go! I'm planning an instrument cluster/steering wheel/clockspring upgrade for the DIS and doing the e-Fan conversion - reading up on that at the moment (looking at something with a min 4000 cfm). I'm also considering upgrading the rear end to a 4.10, which I will be looking into, and getting a performance tune on a new PCM (keeping the original untouched in case I need to revert back to stock at any point). Looking at getting Ascender taillights as well, and debadging, tinting. Due to the nature of my job, I've got Whelen Vertex LEDs, along with some other emergency equipment, going on as well (half way through the installation). I'm also looking at the possibility of a column shift conversion with a foot operated parking brake, and doing something about the gap between the headlights/grille and the front bumper.
I plan on keeping her for a long, long time.
