Need help on a few issues.

Mando Ruiz · July 2, 2018

Ok. So I was finally able to take my 06 5.3L gmc sierra on a road trip. I recently bought the truck. It's obvious the previous owner didn't take much care of it. When I first bought it, I was having the water at blue pcm connector/fan constantly running issue and knock sensor code. I have since fixed both issues. Here's a couple more issues I'd like help on.

#1

On this road trip I got the "tighten fuel cap" message followed by a CEL. I also notice a strong fume smell in the cab when I come to a stop and ac is on. The smell isn't there when the truck is moving, it's only when the truck comes to a complete stop. On the road trip the CEL eventually turned off on its own but the smell is still there when I'm at a stop. I checked the fuel cap and it looks to be in good shape. Any clue as to where the fume smell is coming from? Does it have to do with the "tighten fuel cap" message?

#2

This road trip had a lot of downhill drives. I noticed I had to be on the brakes constantly. That would cause a bad brake pad smell and heat I'm sure. Does this just mean previous owner installed cheap pads?

#3

Both my mirrors move a lot. Not the actual mirrors, just the glass. Is there a way to fix that? It's a little annoying.

Any help would be appreciated!

sefiroxx · July 2, 2018

Not sure on the glass

Brakes: when I buy used , I do full tuneup, fluid change and compete brake overhaul (safety). So the same.

Fume: need to check fuel lines especially at fuel pump and evap canister. There is a solenoid for the evap system to allow fuel vapors to be captured and then released into the intake. Need to check the line is connected. Also, there is a vent to atmosphere function that ensures that high pressures are not not contained. That vent could be stuck open.

txab · July 2, 2018

Are they towing mirrors. If so, and they are aftermarket, many people have that problem and so far I've seen no real fixes.

Brake issue could be from cheaper pads. As suggested, I'd take a good look all around and see what condition they are in and replace them with a high quality pad/shoe. Also use your transmission and engine to help provide breaking down hills too if possible.

Fumes, do as suggested above and read the stored codes and post them.

Also post here or in your other thread about how you conquered your moisture in the ECM issue so as to help the next guy

Supreme Pizza · July 2, 2018

My mirror glass was loose, so I put super glue on a long semi flexible piece of rubber and snaked in behind the glass. There was a bracket that the mirror glass was attached to, and there was play between the two. I wedged the rubber between the two, and it resolved the issue. Your mirrors may be a different design, but if you rotate the mirror one direction or the other, you should be able to see where the freeplay is coming from.

jatkinson8755 · August 14, 2018

regarding the mirrors - are you sure the drive unit itself isnt suffering from a broken plastic spur gear ? I know this company makes all metal gears for the mirror fold units, you can check them out. Also, they do make fixes for the towing mirrors too.

http://www.gruvenparts.com/shop-by-car/gm-truck