Intermitent NO START, dealer can't diagnose, C5 Z06
Thread Starter
Instructor
Joined: Jun 2011
Posts: 227
Likes: 0
From: Mesa, AZ
Intermitent NO START, dealer can't diagnose, C5 Z06
So here is the issue.. The car drives and starts great most of the time, but randomly it will just not crank. It has a new battery, I cleaned all the contacts on the keys with alcohol and still no avail. All electronics work fine when it doesn't start, headlights open/close, gauges sweep, radio, etc. but just no cranking at all. I do not get the "pass key" error but I HAVE seen it once, just never since then. Only electronic mod on the car is a CLB and it has 37k miles.
Here is what happened the last time: I drove 10 mins to dinner, parked outside, ambient temp was hot(arizona summer) so roughly 105 degrees, let it sit for an hour, came back out.. no start. Tried disconnecting battery, no go. Left the car there for an hour, came back, and it fired back up.
Every time I am about ti get it towed somewhere and I come back to the car it starts right up, its very weird. And every time this has happened it has been hot outside so possibly heat soaked.
I took it to the dealer and they can't replicate it, it's been there for about 5 days.. not sure what to do at this point. I am about to just start doing things in search of fixing, I do not know electrics in cars at all. I figured I could start by bypassing VATS, and then move on to the starter and see if the solenoid is bad. Any ideas?
Here is what happened the last time: I drove 10 mins to dinner, parked outside, ambient temp was hot(arizona summer) so roughly 105 degrees, let it sit for an hour, came back out.. no start. Tried disconnecting battery, no go. Left the car there for an hour, came back, and it fired back up.
Every time I am about ti get it towed somewhere and I come back to the car it starts right up, its very weird. And every time this has happened it has been hot outside so possibly heat soaked.
I took it to the dealer and they can't replicate it, it's been there for about 5 days.. not sure what to do at this point. I am about to just start doing things in search of fixing, I do not know electrics in cars at all. I figured I could start by bypassing VATS, and then move on to the starter and see if the solenoid is bad. Any ideas?
Burning Brakes
Joined: Jun 2010
Posts: 769
Likes: 1
From: Columbia TN
I had a similar issue, although it wouldn't start period. We checked everything!! Turned off VATS and still no go. It was on a Sunday so no dealerships were open when we determined it was a bad ignition switch. The switch wasn't reading the resistance in the key so we found the right combo of resistors hooked them together and then bypassed the security feature in the switch. She started right up.
As you can tell I don't know all the technical terms for what we did. I just know it's the only thing that worked.
Good luck.
As you can tell I don't know all the technical terms for what we did. I just know it's the only thing that worked.
Good luck.
Melting Slicks
Joined: Jan 2009
Posts: 2,127
Likes: 33
From: Easley/Anderson South Carolina
Let me ask you this, when it doesnt start you have power to everything in the car, fuel pump whine everything, but no starter solenoid click, correct?
If so, I had the exact same issue with my C5, which to be honest, I never got specifically pinpointed down before doing an engine replacement. (failed cam lobe) When I put the replacement engine in, I replaced the starter with a brand new one, not a reman unit. I have not had another no start condition since. (Mine started out 1 time every 2 weeks, all the way to 2 or 3 times a day)
If so, I had the exact same issue with my C5, which to be honest, I never got specifically pinpointed down before doing an engine replacement. (failed cam lobe) When I put the replacement engine in, I replaced the starter with a brand new one, not a reman unit. I have not had another no start condition since. (Mine started out 1 time every 2 weeks, all the way to 2 or 3 times a day)
Thread Starter
Instructor
Joined: Jun 2011
Posts: 227
Likes: 0
From: Mesa, AZ
Let me ask you this, when it doesnt start you have power to everything in the car, fuel pump whine everything, but no starter solenoid click, correct?
If so, I had the exact same issue with my C5, which to be honest, I never got specifically pinpointed down before doing an engine replacement. (failed cam lobe) When I put the replacement engine in, I replaced the starter with a brand new one, not a reman unit. I have not had another no start condition since. (Mine started out 1 time every 2 weeks, all the way to 2 or 3 times a day)
If so, I had the exact same issue with my C5, which to be honest, I never got specifically pinpointed down before doing an engine replacement. (failed cam lobe) When I put the replacement engine in, I replaced the starter with a brand new one, not a reman unit. I have not had another no start condition since. (Mine started out 1 time every 2 weeks, all the way to 2 or 3 times a day)
Yes that is the exact issue, EVERYTHING works, I can hear a relay clicking the in passenger footwell as well when I try to start it and unclick when I turn the key off. Fuel pump whines, gauges do their full sweep, etc. Battery is at full charge, and new. I'm thinking it kind of points to a starter or starter solenoid issue and I'm willing to just replace the whole stupid thing if that is a possible culprit..
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
90% chance you have a BAD STARTER SOLENOID! Grab you a 20" long piece of rebar, insulate it with tape, the next time it wont start,, snake that bar down between the exhaust and THUMP the starter/solenoid and then try it. If that solves the issue,,,, replace the SOLENOID!!!
If that isnt it, you have some troublehooting to do in the starter circuit. Could be the Theft Deterrent Relay also.
My bet,,, SOLENOID. Been there done that thrown away the T shirt.
If that isnt it, you have some troublehooting to do in the starter circuit. Could be the Theft Deterrent Relay also.
My bet,,, SOLENOID. Been there done that thrown away the T shirt.
Thread Starter
Instructor
Joined: Jun 2011
Posts: 227
Likes: 0
From: Mesa, AZ
Thanks Bill, I was reading some of your threads earlier. I will give that a try and see what happens next time it wont start! If that is the problem you know a lot more about these cars then the dealer does.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Sep 2003
Posts: 6,276
Likes: 227
From: Farmington CT
Cruise-In VII Veteran
1. car in gear, key OFF, push back and forth next time it fails to 'move' starter, ONLY WORKS IF AT 'no start' condition
2. BAD ignition switch
3. loose 13mm nut on starter connection
I've seen all 3, I vote for the first, it'll get worse
www.gmpartshouse.com for a new Delco unit
2. BAD ignition switch
3. loose 13mm nut on starter connection
I've seen all 3, I vote for the first, it'll get worse
www.gmpartshouse.com for a new Delco unit
Thread Starter
Instructor
Joined: Jun 2011
Posts: 227
Likes: 0
From: Mesa, AZ
Put a new starter in the car (that has a new solenoid obviously) and am going to be driving it constantly for the next week to see if the problem reappears. It's been parked for a couple of weeks.
We will see what happens! (crossing fingers)
We will see what happens! (crossing fingers)
Burning Brakes
Joined: Jul 2006
Posts: 773
Likes: 44
From: San Francisco Bay area CA
I had the same issue, replaced my starter as well. You should continue to be good-to-go. 
