Random/Intermittent No Crank. halp!

[OldTahoe]

Hi everyone,
2000 5.3 Newer body Style Tahoe 250k miles

Trying to diagnose this random issue. Its been typically hot and humid but happens after sitting outside. I don't think it has happened after sitting at night in the garage.

Symptoms- No Crank but 1 Click. I will typically mess with everything, shifter, locks, a bit of lite prayer etc.. and after a while I have been able to get it to crank.

I have replaced the Starter and Ignition relay since it was fast and easy. The Starter itself was replaced about 2 years ago and it was a refurb. I have not been able to find any
pattern/hints from moving the Shifter around or jiggling the key in the ignition when it happens or when its cranking normally.

Today its cranking normally in the garage and I while doing some tests, at first it did not start (but did crank) in neutral but it was cranking in park and I tried again in Neutral and it started. It does not seem to be a passlock issue since it is not cranking when it does this.

It's getting more frequent and I'm concerned I'm going to get stranded.

Anyone else had this issue? Any ideas of what to check next?
Thanks!

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

It's time to get the volt meter out and check voltages at the starter first. Do you had 12 volts on the starter's main electrical lug? Do you have 12 volts at the starter's trigger electrical log, when the ignition SWITCH is moved to start, and do you consistently get 12 volts there every time that you turn the ignition switch to start? Ignition switches do fail on these trucks, and for me, it was a degenerative process over time, like you are experiencing.

Other knowledgeable folks will chime in with questions and suggestions.

 

[OldTahoe]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

It's time to get the volt meter out and check voltages at the starter first. Do you had 12 volts on the starter's main electrical lug? Do you have 12 volts at the starter's trigger electrical log, when the ignition SWITCH is moved to start, and do you consistently get 12 volts there every time that you turn the ignition switch to start? Ignition switches do fail on these trucks, and for me, it was a degenerative process over time, like you are experiencing.

Other knowledgeable folks will chime in with questions and suggestions.

Hey, thank you! I'l try to get some pics soon. I did check for 12V at the Starter Relay (with relay inserted) cranked it and check 87 was it? And yes, I had 12v there. I may replace the switch as I think it is something I can do. I have already taken the Steering cover off but I have not looked closely at the switch.

That is a square unit correct?

Were your degenerative symptoms the same? Like random 1 click, no crank?

After some more research, I think the starter is going bad. 2 Things lead me to this. 1) I found a couple of videos that show the single loudish click as the starter going bad. 2) I asked CGPT if the no crank when hot (engine hot and weather hot) showing up (as opposed to next day sitting in cooler garage-- cranks) was a common symptom and here is what the Search Engine said:

Yes — that’s actually a classic symptom of a starter motor on its way out. A few reasons why a failing starter may work better when it’s cool and act up when hot:

1. Heat Soak of the Starter Motor
   • When the engine bay gets hot, the starter windings and armature expand slightly. If the bearings or bushings inside the starter are worn, this expansion causes extra friction, making it harder for the starter to spin.
   • Electrical resistance also increases with temperature, so the already weak windings draw more current but produce less torque.
2. Worn Solenoid or Plunger
   • The solenoid (small cylinder attached to the starter) engages the gear. Heat can make the solenoid coil less efficient and the plunger stick, so sometimes it won’t push the gear forward or won’t make a solid electrical connection until things cool.
3. Commutator/Brush Wear
   • The brushes and commutator inside the starter motor wear down over time. When hot, expansion can worsen poor contact, reducing the flow of current.
4. Electrical Resistance in Cables
   • Heat also increases resistance in old or corroded battery and ground cables. This makes voltage drop worse when hot, so the starter gets less juice.
5. "Heat Soak" Specific to GM Trucks/SUVs
   • Since you’ve mentioned a 2001 Tahoe before: GM starters, especially on the older Vortec engines, are notorious for heat soak problems. Exhaust manifolds run close to the starter, and when hot, it struggles to crank until it cools down.

SO, you can take the above for what it's worth :^) BUT, I am going to gamble on the 15 month old starter going bad and having it replaced tomorrow. I'll check back in after a 4-6 week test.
Thanks again!

 

[rdezs]

Remanufactured starters these days do not have a good reputation.... It is definitely worth purchasing a new AC Delco unit.

Symptoms you describe that change with humidity and temperature are very characteristic of an electrical issue. A couple things to check first:

1. Stop by one of the auto parts stores like AutoZone that offers free load testing of your battery on the vehicle, as well as your charging system. But if your battery overnight doesn't hold 12.6 volts, that's a pretty good sign it's on its way out. Keep in mind you can have 12 volts, but on an old battery it may only have half of the amps it was originally rated at.

2. Battery cables. This is more of a maintenance item, particularly with the age of the vehicle. They may look okay on the outside.....

3. Clean and tighten all ground connections. (As well as the battery terminals)

Once you know beyond the doubt that you have a good battery, good alternator, battery cables and clean ground locations..... Either you will find that solved the problem, or at least you can continue troubleshooting knowing that the basics are working well.

 

[rdezs]

One more note..... Make sure you have that heat shield snapped on the top of the starter solenoid. It's not something you want to leave off.

 

[OldTahoe]

Remanufactured starters these days do not have a good reputation.... It is definitely worth purchasing a new AC Delco unit.

Symptoms you describe that change with humidity and temperature are very characteristic of an electrical issue. A couple things to check first:

1. Stop by one of the auto parts stores like AutoZone that offers free load testing of your battery on the vehicle, as well as your charging system. But if your battery overnight doesn't hold 12.6 volts, that's a pretty good sign it's on its way out. Keep in mind you can have 12 volts, but on an old battery it may only have half of the amps it was originally rated at.

2. Battery cables. This is more of a maintenance item, particularly with the age of the vehicle. They may look okay on the outside.....

3. Clean and tighten all ground connections. (As well as the battery terminals)

Once you know beyond the doubt that you have a good battery, good alternator, battery cables and clean ground locations..... Either you will find that solved the problem, or at least you can continue troubleshooting knowing that the basics are working well.

Great tips thanks! I'm having the starter replaced today. The battery is about 15 months old but I'll check the above anyway.

 

[OldTahoe]

One more note..... Make sure you have that heat shield snapped on the top of the starter solenoid. It's not something you want to leave off.

Ya know, I wondered if perhaps the previous repair left if off? I will verify today.


UPDATE: NO Heat shield on current Starter.. I just ordered one and hopefully can snap on to the new starter tomorrow.

 

[rdezs]

The exhaust manifold likely cooked it....

 

[lyncht1967]

If the starter doesn't work out, I would be highly suspect of a bad battery to block ground cable. try connecting one black jumper cable lead to negative battery post and other end to block next time as a test bypass.