Misconceptions and oddities about our platform

Mounce

Well-Known Member
Envoy_04 said:
This one's for Envoy owners

"My Envoy's fog lights point down on the road so close in front of the vehicle that they're almost useless, I've almost quit using them altogether because they just aren't effective."
Your fog lights ARE adjustable, just like your headlights. Near the wires where the bulb plugs in at the back of the fog light assembly behind the bumper, there is a small adjustment screw that sticks down. It takes a torx socket to turn it, I believe the same size as the easily accessible headlight one up top. Loosening this screw (counter-clockwise) will raise the light upward and make it shine further down the road. Tightening this screw (clockwise) will lower the light and make it shine closer to the ground directly in front of your bumper. Use small adjustment increments, a little bit of a turn equals a lot of light beam movement.
my trailblazer's fogs are also pointing at the ground. Already found the adjustment but didn't know what to use to turn it, thanks!
 

sunliner

Well-Known Member
Mark20 said:
If you're replacing the thermostat you should replace the coolant temperature sensor right next to it.
Agreed....however around 06, they moved it to the passenger side, extreme rear. Just posting so other people don't drive themselves crazy looking for it like I did.
 

rocketsound

Member
While you're changing your thermostat is a great time to install a block heater, if you live in a colder climate. It's located just above the thermostat and to the rear, next to the coolant temp sensor. The large plug with 17mm allen recess in it unscrews from the block and you just thread in the heater. much easier to do when the alternator is out of the way! Sorry I failed to get pictures of it at the time, I'll update with pics next chance I get.
Katz 11484 is what I used on mine. Got it from NAPA
Might want to remove the thermostatic controller from the cord, it doesn't switch on the heater until -18 F!
 

Mark20

Well-Known Member
Considering the Silverado sits out all year the Kats may be a good idea for it. From their catalog it appears the 11484 will also fit the 5.3L.
 

rocketsound

Member
It does, I put one in my Suburban. All the 5.3l, 6.0l and I believe the 8.1l have the large plug that unscrews to allow you to install the block heater.
On the 5.3l & 6.0l the plug is above the oil filter in the left (driver's side) rear of the block. Requires a 17mm allen bit to remove the factory plug. Here's a pic of the v8 so you get an idea what the plug looks like. Same plug on the 4.2l just near thermostat on driver's side of engine.

 

Mark20

Well-Known Member
Do you have to drain the coolant or can you swap it out fast enough to minimize its loss?
 

rocketsound

Member
On the v8, the plug in the block is just about the lowest point in the system, so you're going to get wet or lose all your coolant. Unless you place a drain pan under it first. I had a 2005 Silverado up on the lift this morning, and noticed that it did not have the block drain plug that we've been discussing. It was a "B" code engine with an aluminum block. It's possible that only the motors with iron blocks have the plug. I will pay closer attention and see if that's true.
 

Kazz

New Member
Question on the oil pressure gauge. If it is a switch, why does my gauge fluctuate like a normal gauge? If the sending unit is a switch, wouldn't it stay at 40 or nothing versus fluctuating?
 

Mounce

Well-Known Member
Kazz said:
Question on the oil pressure gauge. If it is a switch, why does my gauge fluctuate like a normal gauge? If the sending unit is a switch, wouldn't it stay at 40 or nothing versus fluctuating?
I believe it's the PCM fabricating fluctuations to fool people. Mine does the same thing.

4.2 = fake readings
5.3 = real readings
 

The_Roadie

Founding Member
Administrator
That's right. It was presumably cheaper for GM management to omit the analog sensor and tell the the PCM coders to calculate fake values for the gauge to take into account RPM and perhaps temperature changes into the fake data.

It is evidence of total intellectual dishonesty motivated by the management culture of saving a dime no matter how much bad karma you're generating. As an engineer, I have very little respect for designers who obey such orders. My management may be frugal, but they know better than to ask me to lie to the customer like this.
 

No Tyme

Silver Supporter
Earlier in the thread radio back lighting was discussed. I presume it is the same for dash lights... solder required to replace and install...
How hard of a job is it? Has anyone done this?

Also anyone use these cargo shade covers? I don't want to add something that is going to rattle or make noise, but the idea of privacy is nice.
 

Mounce

Well-Known Member
For the lights check out the led mod thread starting at the beginning.
 

Mooseman

Moderator
I use the cargo cover occasionally. Kinda neat and it doesn't rattle. It does get in the way when you need to transport larger items. It comes out easily but you're then you're stuck with it taking up some space.

I was lucky when I found mine in the local pick-a-part and cost me just $10.
 

No Tyme

Silver Supporter
Mooseman said:
I use the cargo cover occasionally. Kinda neat and it doesn't rattle. It does get in the way when you need to transport larger items. It comes out easily but you're then you're stuck with it taking up some space.

[SIZE=11.9999990463257px]I was lucky when I found mine in the local pick-a-part and cost me just $10.[/SIZE]
WOW, you got a deal. I am having second thoughts because I can't find one under $100. LOL... Good to know if I do decide to pick up one they don't rattle. Don't like anything that makes annoying noise in cars.
I do have a full size pickup for the larger items... My Trailblazer is a go to work vehicle.
 

djthumper

Administrator
Mooseman said:
I use the cargo cover occasionally. Kinda neat and it doesn't rattle. It does get in the way when you need to transport larger items. It comes out easily but you're then you're stuck with it taking up some space.

I was lucky when I found mine in the local pick-a-part and cost me just $10.
I got mine for $20 and it was in pristine condition.
 

littleblazer

Gold Supporter
SnowBlazer said:
I've always wanted a shade. No luck though :sadcry:

Roadie was going to sell me his but I haven't seen him on in the longest time. Hope all is well over there.
I see him on on the Facebook page quite a bit.

One thing I never quite understood was why is there a fuse panel thing on the drivers side dash, like the full size. But it's not actually there. I think....
 

northcreek

Well-Known Member
SnowBlazer said:
I've always wanted a shade. No luck though :sadcry:

Roadie was going to sell me his but I haven't seen him on in the longest time. Hope all is well over there.
I have a grey one from my Denali...make me an offer ...Mike
 

No Tyme

Silver Supporter
Just my luck. I picked up a shade from eBay and it is a bit darker than I wanted... More of a camel color and my interior is shale... I guess brown against tan isn't too bad. :frown:
 

l008com

Well-Known Member
There is only a switch detecting oil pressure, so it's either off (0PSI) or on (reads 40PSI, but can be 12+)
All the more reason oil pressure should just be a light on the upper dash, and it's gauge space should be a transmission temperature gauge.

Also, you said "on the i6". Does that mean on the 5.3's the oil pressure gauge is "real"?
 

Paul Bell

Silver Supporter
I see him on on the Facebook page quite a bit.

One thing I never quite understood was why is there a fuse panel thing on the drivers side dash, like the full size. But it's not actually there. I think....
If you wanted to remove the dashboard from the truck you'll see that these are bolt access covers.
 

iraqvet13f

New Member
"I went to change my spark plugs; when I removed the coil pack for cylinder 4/5, I looked in before starting and noticed there was a little bit of water in the bottom/a little rust on the bottom of the plug! Is something broken, did I blow a gasket or something?"
This is actually a known problem. Notice that there's no weatherstripping (rubber seal) on the back of the engine compartment, either on the hood or the body metal. What happens is sometimes in the rain or when running your wipers, some water trickles down onto the block and may get past the coil pack "seal." I use the term loosely because there's only one bolt toward an extremity holding the pack down, so it's much more difficult to get a proper seal around the entire perimeter. If there's some water present, soak out what you can, and let the rest evaporate until dry before removing the plug. When reinstalling your coil packs, you could ensure the area where the seal touches, and the seal itself, are completely clean. Making sure the bolt is properly torqued can aid in sealing. The gasket that is by the inside of the spark plug wells is actually used to retain oil; if you find oil in the spark plug well, THEN you have a bad gasket.

"I have a light that came on, I looked it up and it's the Reduced Engine Power light. How does it know I'm not getting full power, and what did I break?"
Luckily, this isn't just any issue causing the REP light. The REP light comes on when the expected position of the throttle plate and the actual position of the plate do not agree. Imagine this: you're accelerating briskly, and then you let off the gas pedal when you reach the speed you want. Suddenly the REP light comes on. Did you blow something? Is a valve stuck from your little bit of fun or something that is making you lose power? Luckily, it's not (relatively speaking) that severe! What likely happened is that you let off the accelerator, which tells the PCM to close the throttle, and then the throttle didn't go to where it was supposed to. This system is designed to give you a "limp" mode to at least be able to safely pull over or get to a shop/home if you're not far away, and it compromises by not allowing the throttle to open very far. This ensures that you are much less likely to have a runaway vehicle like we all remember Toyota doing a massive recall for. And yes, your GMT360 is drive-by-wire.
"I went to change my spark plugs; when I removed the coil pack for cylinder 4/5, I looked in before starting and noticed there was a little bit of water in the bottom/a little rust on the bottom of the plug! Is something broken, did I blow a gasket or something?"
This is actually a known problem. Notice that there's no weatherstripping (rubber seal) on the back of the engine compartment, either on the hood or the body metal. What happens is sometimes in the rain or when running your wipers, some water trickles down onto the block and may get past the coil pack "seal." I use the term loosely because there's only one bolt toward an extremity holding the pack down, so it's much more difficult to get a proper seal around the entire perimeter. If there's some water present, soak out what you can, and let the rest evaporate until dry before removing the plug. When reinstalling your coil packs, you could ensure the area where the seal touches, and the seal itself, are completely clean. Making sure the bolt is properly torqued can aid in sealing. The gasket that is by the inside of the spark plug wells is actually used to retain oil; if you find oil in the spark plug well, THEN you have a bad gasket.

"I have a light that came on, I looked it up and it's the Reduced Engine Power light. How does it know I'm not getting full power, and what did I break?"
Luckily, this isn't just any issue causing the REP light. The REP light comes on when the expected position of the throttle plate and the actual position of the plate do not agree. Imagine this: you're accelerating briskly, and then you let off the gas pedal when you reach the speed you want. Suddenly the REP light comes on. Did you blow something? Is a valve stuck from your little bit of fun or something that is making you lose power? Luckily, it's not (relatively speaking) that severe! What likely happened is that you let off the accelerator, which tells the PCM to close the throttle, and then the throttle didn't go to where it was supposed to. This system is designed to give you a "limp" mode to at least be able to safely pull over or get to a shop/home if you're not far away, and it compromises by not allowing the throttle to open very far. This ensures that you are much less likely to have a runaway vehicle like we all remember Toyota doing a massive recall for. And yes, your GMT360 is drive-by-wire.
Ok, So if the REP light comes on, what can I do to fix this? Repair / clean the throttle body?
 
Last edited by a moderator:

Mooseman

Moderator
You'd have to use a code reader and get the accompanying code to pinpoint the issue.
 

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