All the lights lightly flicker when idling

[joeblackavalanche]

Down 4 quarts in a few months is a big problem and points to more than just the AFM. I mean, the engine takes 6qts with a filter change, so you lost two thirds of your oil in a few months - not good. Do you have any significant leaks?

I'd be happy averaging 15mpg in my Avy. I'm lucky if I get 14...

yeah i think walmart screwed up to be honest

 

[Wpolonavyguy]

with the battery connected i stupidly cleaned 2 grounds i could find and only one of them started arcing while pulling it apart and putting it back together after cleaning, that was the one connected to the top of the engine to the firewall by a braided strap.......the one from the battery terminal to the frame didnt arc while messing with it......maybe thats a problem

The grounds shouldn't arch or spark with keys out & engine off.
Makes me think you're battery is supplying power around the ignition switch. Other people had similar issues with paricidic battery drain. Power connected battery hot forward of ignition switch.
I could be wrong but I've never had sparks cleaning grounds.
Good luck, my avy is doing much better after torque converter swap & evap hose replacement.
My 07 has to be the ECU starting to crap out, wiring loose somewhere, or temperature causing intermittent air leakage.
The check engine light pops on with communication troubles, and air leak evap codes then light shuts off & runs fine no issues? Maddening to troubleshoot , smoke machine arrives tomorrow to test for leakage all vacuum areas.
If Good without leaking, I get to meter wires & if wires ok might have to replace/program A ECU.

Most car/truck electrical easy to check with multi meter, cheap harbor freight ones work decent. Ohms read resistance so closer to zero is good like .01 higher numbers into reading means power not flowing well. O/l means no power flowing usually when pins not touching anything.

 

[Wpolonavyguy]

Oil consumption bad in our Avalanches. I added oil catch cans on both sides pcv vacuum lines. Used copper tubing to route my own pcv hoses to catch cans.
My grounds I clean often can see how fast rust develops on bare metal even here in Southern California.

 

[ToyHauler13]

I've been opening and cleaning any grounds I notice while working under the truck as a preventative measure. I clean the frame where they mount and clean the terminals and put it all back together with some dielectric grease. Finish up with a shot of spray paint over the connection to hopefully weatherproof things a little more. If it wasn't for the winter salting of the roads here I might not get this fussy about it, but it can't hurt. I'll check them again in 10 years and see how this works.

 

[Wpolonavyguy]

Anyone have a good wire diagram showing ecu pins & lines going to tcm,transmission, break module, & body control module.
I need to meter wires to narrow down issues, hate to replace computer if wiring related causing ecu problems.
It improves in heat & worsens cold weather, and rainy weather.
Everywhere I see wiring diagrams they want to charge $ memberships to see clearly.

 

[joeblackavalanche]

I've been opening and cleaning any grounds I notice while working under the truck as a preventative measure. I clean the frame where they mount and clean the terminals and put it all back together with some dielectric grease. Finish up with a shot of spray paint over the connection to hopefully weatherproof things a little more. If it wasn't for the winter salting of the roads here I might not get this fussy about it, but it can't hurt. I'll check them again in 10 years and see how this works.

when i put dielectric grease on my cleaned up grounds i got an engine light......i took them all apart and spray them with contact cleaner and the engine light went away

 

[joeblackavalanche]

Makes me think you're battery is supplying power around the ignition switch. Other people had similar issues with paricidic battery drain. Power connected battery hot forward of ignition switch.

so you are saying there is something draining the battery while the ignition is off? i can say everytime i start my truck the battery gauge reads over 15-16 volts then settles back down after driving a few minutes......its a new battery, not the best brand but it said to charge the battery before installing and i didnt do it being i saw that message after i installed it........i might charge it once the nice weather comes around......ill be doing a lot of things once the weather breaks and i can work on the truck comfortably......

Oil consumption bad in our Avalanches. I added oil catch cans on both sides pcv vacuum lines. Used copper tubing to route my own pcv hoses to catch cans.
My grounds I clean often can see how fast rust develops on bare metal even here in Southern California.

wow......you have a lot going on there.......so oil goes in the catch cans, if you didnt do that where would the oil go without all those copper tubes and cans?

 

[Wpolonavyguy]

That oil gets vaccumed into the air intake manifold then gets burned through engine. I like my spark plugs clean & oil can foul them up some. I added catch cans to help keep track of how much oil is getting pulled out engine.
The battery comment was from reading about sparks seen when you were touching the ground points durring cleaning? If keys out & engine off the ground points on frame/body shouldn't spark at all.
The main battery terminal negative might spark with vheicle off, but other locations shouldn't.
That makes me think you're truck has battery power getting around your key/accessory/switch.
I do remember a timer function supplied power a bit after shutdown for headlight & interior lights.
That I'd only other thing I can account for grounding sparks.

Me today investigating chasis wiring harness, tire rubbed into exposed 3 or 4 copper conductors. Didn't break or cut any luckily but trying to figure if causing computer readings to be off some.
Liquid electrical tape sealed them but thinking, corrosion inside could change resistance readings.
Only trouble is soldier electrical splice & heat shrink can also add lil resistance??

Gotta find color codes for these wires.

 

[joeblackavalanche]

That oil gets vaccumed into the air intake manifold then gets burned through engine. I like my spark plugs clean & oil can foul them up some. I added catch cans to help keep track of how much oil is getting pulled out engine.
The battery comment was from reading about sparks seen when you were touching the ground points durring cleaning? If keys out & engine off the ground points on frame/body shouldn't spark at all.
The main battery terminal negative might spark with vheicle off, but other locations shouldn't.
That makes me think you're truck has battery power getting around your key/accessory/switch.
I do remember a timer function supplied power a bit after shutdown for headlight & interior lights.
That I'd only other thing I can account for grounding sparks.

Me today investigating chasis wiring harness, tire rubbed into exposed 3 or 4 copper conductors. Didn't break or cut any luckily but trying to figure if causing computer readings to be off some.
Liquid electrical tape sealed them but thinking, corrosion inside could change resistance readings.
Only trouble is soldier electrical splice & heat shrink can also add lil resistance??

Gotta find color codes for these wires.

yeah i know the radio will work for 15 minutes after the truck ignition is turned off.......im usually waiting for the wife at drs appts listening to the radio with the truck off.......after the 15 minutes the radio goes off then all i do is push the volume button again and it comes on for another 15 and on and on until the wife gets back.......didnt you mention the use of dielectric grease on the grounds.......for me that is a no no......it made the engine light come on when i did that, i cleaned them off and the engine light went off.......id say use the dielectric grease on plugs only but who am i......just a flunky trying to figure all this stuff out

 

[Wpolonavyguy]

Di electric grease only keeps water out connectors & areas. I believe it ruined a set of spark plugs heat transfer or chemical erosion idk.
I quit using di/electric but someone suggested antisieze with copper particles can help make electric connection & keeps air/water off meatals.
I tried on few of my grounding points.
I'm leaning towards cutting off factory grounding crimp loops & solder or welding new loops on copper conductors.
I'm going crazy trying to diagnose this intermittent problem my truck is having.
Either a power/voltage/grounding thing/ wire connector loose, or one of the 4 computers not 100% .
Hate to replace any of the brains as reprogramming required.
After fix tire rubb wire will open to BCM to visually check wiring & connectors.

 

[Wpolonavyguy]

Gotta decide soldier splice or liquid electrical tape

 

[joeblackavalanche]

Gotta decide soldier splice or liquid electrical tape

so i assume you are checking every wire harness and wire ground to find that green dust.......good for you man.......i bet you find your problem......im going to investigate once summer comes and see if i can find a dirty ground and make new ones like you are doing.......keep us updated with your findings.......im learning stuff

 

[joeblackavalanche]

Gotta decide soldier splice or liquid electrical tape

both good choices.......depends how ambitious you are id say

 

[Wpolonavyguy]

Did cut & use soldier splice, heat gun makes sure water kept out.
That probably wasn't a problem spot but nice to seal up.
Been procrastinating smoke tests, engine light shut itself off again.
May wait till light comes back idk. My luck I'll have to remove manifold & re seal gasket. But smoke will give visibility on where ill need to work.
Will post photos if I find my gremlins.

 

[joeblackavalanche]

Did cut & use soldier splice, heat gun makes sure water kept out.
That probably wasn't a problem spot but nice to seal up.
Been procrastinating smoke tests, engine light shut itself off again.
May wait till light comes back idk. My luck I'll have to remove manifold & re seal gasket. But smoke will give visibility on where ill need to work.
Will post photos if I find my gremlins.

glad your engine light went off......so much to figure out it overwhelms me alot but i keep trucking to tackle the problems.......im 63 and have so much on my plate and it feels so good even when i conquer a little thing.........never give up i always say

 

[Capt.Crunch]

Did you solve the light issue, I'm having the same problem, when I'm on the throttle climbing a hill while on te freeway, my headlights start fluctuating, bright/dim,bright/dim, but I noticed the more I accelerator the faster they fluctuate. I purchased new cables from gm for a mear $120.00 bucks and the ground has the new charge sensor on it, I'm hoping that'll correct this problem.

 

[BainMan]

Did you solve the light issue, I'm having the same problem, when I'm on the throttle climbing a hill while on te freeway, my headlights start fluctuating, bright/dim,bright/dim, but I noticed the more I accelerator the faster they fluctuate. I purchased new cables from gm for a mear $120.00 bucks and the ground has the new charge sensor on it, I'm hoping that'll correct this problem.

Disconnect and clean all grounds? Or at least the main ones? All ground locations (and many other things) for the 2nd gen are detailed in the attached document.

But, I also bought a new main negative/ground battery cable.. Mine only fluctuated at idle, not when at speed, but both seemed to help.

 

[Capt.Crunch]

Disconnect and clean all grounds? Or at least the main ones? All ground locations (and many other things) for the 2nd gen are detailed in the attached document.

But, I also bought a new main negative/ground battery cable.. Mine only fluctuated at idle, not when at speed, but both seemed to help.

Thanks for the diagram, it'll help me out a lot.

 

[Wpolonavyguy]

I got the idle/air flow issue fixed, apparently I didn't get a complete seal on fuel pump when I switched it. I bought a new evap line assembly as original looked cracked enough to leak air but wasn't that. I cut access door under my rear seat and made it as professional as I could.
Bought a pump with two hose ports like original I believe the 3 port pump was Tahoe or different models pump. Sealed with extra gasket sealant non hardening just to be sure no air leaks.
Nice knowing i won't need drop tank if any future pump issues.
Well I got frustrated & ordered all x3 main computers pre-programmed to my vin#.
My issue wasn't the TCM switched that easily, most recent switched ECU had trouble getting key programing done.
FYI drivers door needs to be closed when doing the 10min waiting 5sec off x3 process.
Figured that out after first two tries engine wouldn't crank.
Unfortunately the crankshaft sensor now set engine light needs programming, unfortunately seller didn't give that heads up.
I could still need BCU swapped may switch that before drop at shop or dealer may aswell pay programming all same time.
Bcu has airbags, breaks, & theft deterrent programming needed even with pre-programmed.
I ran my own wire connecting all ground points together to eliminate any bad grounding & piece of mind. Also new battery cables & liquid electrical tape to seal out water at ends may help prevent corrosion.
I may not need switch BCM could hold as extra, might have good shift after crankshaft sensor programmed.

 

[Wpolonavyguy]

Two local shops tried telling me the new ECM was bad & it should learn crankshaft position sensor on its own.
Lucky I have a friend owner of his own shop went and waited around for his break & he used his scanner and did relearn in less than 10min.
He also has a snap/on tpms tool that can do wake up on my Amazon ordered moresensor tpms sensors.
Ten tire shops around my area all didn't have compatible tool appearantly or they just didn't want the business?
Tuesday I'll get tpms sensors on & programmed. After that I believe my Avalanche should be all set for some time I'm hoping.
I am removing door bumper guards & will be testing out my skills painting & clearcoating some blemishes.
Mostly the rear bumper, the rear quarter panel passenger side has cracking I want to sand out & fix.
I'm hoping it wasn't a bad repair cracking now, if I find bondo underneath I won't be very happy.

 

[Capt.Crunch]

Two local shops tried telling me the new ECM was bad & it should learn crankshaft position sensor on its own.
Lucky I have a friend owner of his own shop went and waited around for his break & he used his scanner and did relearn in less than 10min.
He also has a snap/on tpms tool that can do wake up on my Amazon ordered moresensor tpms sensors.
Ten tire shops around my area all didn't have compatible tool appearantly or they just didn't want the business?
Tuesday I'll get tpms sensors on & programmed. After that I believe my Avalanche should be all set for some time I'm hoping.
I am removing door bumper guards & will be testing out my skills painting & clearcoating some blemishes.
Mostly the rear bumper, the rear quarter panel passenger side has cracking I want to sand out & fix.
I'm hoping it wasn't a bad repair cracking now, if I find bondo underneath I won't be very happy.

To be honest, that looks like a past repair, the way the paint is cracking and how the body looks like it has an eye looking indent there, not bad, definitely fixable. Good Luck

 

[Wpolonavyguy]

To be honest, that looks like a past repair, the way the paint is cracking and how the body looks like it has an eye looking indent there, not bad, definitely fixable. Good Luck

That's what a painter friend said usually those weird long bubble cracks are where moisture or bondo epoxy don't allow paint to stick well.
I painted my whole drivers side fender & installed it. I still have to wet sand it & try match the mirror shine.
I still have 5 cans of paint & clear coating to use on all the lil areas & big cracks.
Going to give it a try unfortunately once a vheicle gets to a certain age paint can be more than value of vheicle itself.

 

[Capt.Crunch]

That's what a painter friend said usually those weird long bubble cracks are where moisture or bondo epoxy don't allow paint to stick well.
I painted my whole drivers side fender & installed it. I still have to wet sand it & try match the mirror shine.
I still have 5 cans of paint & clear coating to use on all the lil areas & big cracks.
Going to give it a try unfortunately once a vheicle gets to a certain age paint can be more than value of vheicle itself.

Good luck!

 

[joendoodle]

I always have a good supply f these:

I replace and add them all over, not just in GM's and Ford's OEM "locations"

 

[Capt.Crunch]

I always have a good supply f these:

I replace and add them all over, not just in GM's and Ford's OEM "locations"

Where do you get those ground straps?