2016 Silverado Slow blower motor = Sluggish Engine? Strange.

Martinthezman · July 4, 2021

Hello, I have a 2016 Silverado 4x4 with the 5.3. It is has the manual HVAC system.

I've noticed that there are times this truck runs like a beast, and sometimes it seems weak. The Truck running strong at times and running weak at times has been going on for almost two years [the truck has 50K on it]. Often times on the same 100 mile trip I notice it switches between BEAST mode and weak mode.
There are no codes. I changed plugs and wires. Even turned off the V4 mode to see if it would stop. Nope the same deal.

Recently I noticed [probably been going on the whole time and I just noticed it] that my blower fan sometimes is blowing at about 1/2 power though I have it turned almost all the way up and then suddenly while driving it kicks up and blows hard like it should.. When this happens the Truck perks up and runs like a beast. It is like the FAN speed issue is connected to the sluggish issue.

What would cause this? I had an Nissan Armada [lk] SUV once, and it had a relay in the BCM that was weak, it affected the power to most of the electronics on the car, and caused it to run weak. I noticed a big difference when I replaced the the relay in the BCM. Does the Silverado have an issue like this?

Thanks for the input,
Martin

pokismoki · July 5, 2021

put the battery on charge overnight, see if this helps.. batt voltage is critical to fuel injection and direct injectors probably consume lots of power.

another power hog is our power steering system ,its driven by a motor , needs lots of power to turn those wheels on this heavy truck

towhaul mode also boost voltage thru the software charge strategy, usually take 8-15 minutes to top up the battery while driving

Edited July 5, 2021 by pokismoki

pokismoki · July 5, 2021

try cracking open the window when the blower is operating, you might have a pressure block when the windows are rolled up

Edited July 5, 2021 by pokismoki

Martinthezman · July 6, 2021

Hello, I noticed sometimes the blower fan blows slower than usual. Like half speed when turned all the way up.

Then suddenly it starts to blow like it should.

When the fan blows right the truck runs like beast, when the blower is slow, the truck is sluggish.
What would cause this?
I had an Infinity SUV once, and it had a relay in the BCM that was weak, when I changed it, everything worked better and it ran a lot better.
Could be the same deal?

CrawlSlow · July 6, 2021

V4 kicked in! Why double post?

MikeBMW · July 6, 2021

34 minutes ago, CrawlSlow said:

V4 kicked in! Why double post?

I guess he's just looking for help?
Happens often on this forum with the many different sections.
I suppose I'm guilty of repeating a post in different sections.
Mostly for information in a more appropriate section.
No biggie, eh?

KARNUT · July 6, 2021

Could be a bad ground. Strange things can happen with electronics. I had a battery going bad on my truck. When I started it the transmission would be in tow-haul mode and wouldn’t come out. Other electronics were affected. Change the battery problems solved.

Martinthezman · July 6, 2021

Hello, I replaced the Battery and have V4 mode turned off. And it does the same thing.

CrawlSlow · July 7, 2021

Drive the truck with no fan and no AC to see if truck goes back to normal. If goes back to normal, test this out.

1. Drive truck with only fan mode (no AC) - does it still drive normal?

2. Now drive with AC on max - it should being back your problem, correct?

Martinthezman · July 7, 2021

Hello, it runs sluggish with fan off, ac off, fan on, ac on at times. I don't think the fan or hvac is the problem... I think what ever causes the fan to blow slow, is also causing to it to run sluggish...