Frustrating intermittent engine starting issue (2009 Colorado pickup)

[rbgarr]

Every few weeks turning the ignition key results in nothing, not a sound. Wait ten minutes and it starts right up. Summer, winter, wet, dry, it's random. Not a battery problem. Maybe some kind of relay problem? Local mechanic can't find it because the problem is so random and "fixes itself". I'm not about to leave the truck at the shop for three weeks until it does it again.

[Jim Mahan]

Didja try jigglin' it? Sometimes if you jiggle it.

Loose connection, like battery or alternator ground, connection to the starter solenoid, or in the ignition switch?

[P.I. Stazzer-Newt]

It is possIble to spend an ungodly amount of time and money chasing a "relay problem".

Typically the relays are between £5 and £10 a throw - just change all of them - certainly all involved in ignition and fuel systems.

A single dodgy connection can have much the same effect.

[ron ll]

Bet it’s a bad ground connection, cable, starter housing, etc. .

[Canoeyawl]

Start with cleaning the battery posts and terminals, then migrate to the first "buss" connection of the "hot" side cable (starter/cab chassis rely) then the first ground connection, batt to chassis. Then if the problem repeats, proceed down the chain of connections, both "hot" and ground, but only one at a time between tests.

anecdote:
I once had a "service call" for a tractor that had an intermittent start problem (new batteries) and after some basic diagnostic work found a fine layer of "dirt/sand" had gotten between the batt post and the terminal. When the starter was activated the current surge melted the "dirt" forming an "almost" invisible layer of glass around the post, completely insulating it! Took a while to figure that one out...

[Garret]

Dunno if it's a similar setup, but... My 14 GMC 1500 (same a s a Chevy Silverado 1500) has kind of a bus bar setup on to of the battery. The terminals hook into the bus & then there are 3 or so large wires & a connector (2 wire plastic, large flag connectors inside) with roughly 12 gauge wire coming off the other side. I had a situation where the truck wouldn't start - actually nothing at all would come on - no lights, dashboard, nuthin'. I found that wiggling that connector would "fix" it for a while. I finally took it all apart, cleaned everything & bent the female connectors on the 12 ga. connection to make them tighter (all the others are nuts on studs). That seems to have fixed it.

[SaltyD from BC]

Good advice above, I too lean to an iffy ground somewhere being intermittent like that. Also check any start lock out scenarios like clutch needing to be depressed if a standard or has to be in park if auto, could be a controller or switch that's iffy too.

[ron ll]

Had a ‘51 Chev 1/2 ton with a six volt system that had starting problems. Told a mechanic I wanted to solve it by switching everything to twelve volts. He said just clean all the ground connections and the six volts will work fine. He was right.

[LeeG]

I wonder if modern vehicles are susceptible to malware/viruses.

[JayInOz]

Loose connection on the starter?

[Ian McColgin]

My Jeep has this problem and it's without doubt related to how for manual transmissions you can't start without the clutch fully down. Getting it fixed end of the week.

[David W Pratt]

My truck also has the requirement that the clutch be depressed. And that means to the firewall, far beyond where it needs to be to shift. Tha truck also has a switch to by pass the clutch depression requirement.

[Brian Palmer]

Maybe it's the ECU?

[hawkeye54]

Could you possibly have worn contacts within the ignition switch itself ? ( Are there a lot of keys on your keyring ? )






Rick

[ShorelineJohn]

I would check the systems that need to be, foot on brake and car in park (or clutch depressed) and so should any mechanic. Those switches usually work off the hydraulics, (brake and clutch) low fluid could cause it but usually don't. The gear selector is usually a opto-coupler with a little piece plastic that moves through it, they are very susceptible to dust (like dust bunnies dust) and blowing them out might solve the problem. But these are all things the mechanic should know, and check.

[Breakaway]

"Its always a bad ground."
Well, not always. But common enough that the above is a common throwaway line.

[Jim Bow]

Get out and get under. Pull every cable or wire on the starter and its solenoid. Clean them with a wire brush, pyt them back on. Do the battery too.
Bingo, Bob’s yer uncle.

[wizbang 13]

Not always a bad ground, but it seems it’s always an American truck .

[epoxyboy]

Every few weeks turning the ignition key results in nothing, not a sound. Wait ten minutes and it starts right up. Summer, winter, wet, dry, it's random. Not a battery problem. Maybe some kind of relay problem? Local mechanic can't find it because the problem is so random and "fixes itself". I'm not about to leave the truck at the shop for three weeks until it does it again.

"Nothing" as in not even the dash lights up, or just nothing from the starter?
Another thing to look at is the brake light circuit, if it's one of those vehicles that requires your foot on the brake pedal to allow it to start.

Pete

[Jim Mahan]

If you give up and sell it cheap to some young eager beaver, you'll likely see him driving around town and you can ask him what it was.

He'll say it was a loose ground wire.

[George Jung]

Had a similar issue with a 2011 dodge grand caravan - happened rarely, but when it did, it was 'dead' until the next day - and then would start like a champ. The first time it happened (I was stranded), had to be towed to a dealer. Started immediately at their garage. Although infrequent, it was disruptive, unreliable. I left it at the dealer for a month, after several 'visits' (off warranty, of course) failed to find a problem. They said it never acted up in that time - but doing a search, found this is a common problem in these vehicles - with variable 'causes'. We got rid of the car.

[Canoeyawl]

I once had a battery (in a car) with an intermittent internal open and it would do exactly that, no power throughout the system - once in a while. At the most inopportune time. A jump start and it would be fine for a week or so.

Today if this happened (after I checked the obvious connections) I would try another battery. This I have only encountered once in a career of trouble-shooting.

[Jim Mahan]

Once, a long time ago, I had a two year old, low mileage seventy Pontiac Bonneville four-fifty-five. A great car, though not my choice, it was picked out for me by my then FIL who was a big shot at GM and pulled a string or two with a local dealer. It was easy to work on and maintain, and I was proud of my ability to do that, having been lucky and had a great auto shop teacher in high school.

So I was flustered and at a loss to discover one day, on the way out to a picnic by the lake, that my car suddenly wouldn't start. I had stopped at a convenience store on the highway, and when I got in to leave, the car acted like it had a dead battery. That was impossible, thought I in my teen hubris. And then a geezer happened by who told me to clean the battery terminals. But jeez mister, the car started fine this morning, and never gives me a problem and nothing has changed. The battery is fine.

But I had no other idea and no triple A at the time. So I unbolted the terminals, scraped the posts clean with my pocket knife until they were shiny, did the same inside the cable ends, and when I bolted it back up, it was like putting in a new battery, the car started up and ran fine.

That lesson, that the invisible build-up of a thin layer of oxidation between the posts and the clamps is enough to eventually equal insulation, was a life-saver more than once. It looks fine, but it's snot. Which is why it's important when troubleshooting, to dismantle and clean the suspected grounds etc. Just because it was fine right up until now and hasn't been disturbed, doesn't mean the electrical connection is still good. And resistance adds up, at every electrical junction and switch. Especially handy to know if you own an old British sports car.

[rregge]

Check the ground, then remove all the battery wires and using a wire brush clean the terminals and the wires, use a batter protection spray and reassemble.

[George Jung]

uSEFUL thread; but curious - how many here, do this sort of maintenance, when they're having no problems? Likely would be warranted.

[rbgarr]

Thanks everyone for all the suggestions. I look forward to working my way through them.

Meanwhile, if I thought I had problems, I just read that Prince Harry described this one in his new tell-all book 'Spare'. Yikes. https://www.vanityfair.com/style/202...n-the-epilogue

[JayInOz]

Had a similar issue with a 2011 dodge grand caravan - happened rarely, but when it did, it was 'dead' until the next day - and then would start like a champ. The first time it happened (I was stranded), had to be towed to a dealer. Started immediately at their garage. Although infrequent, it was disruptive, unreliable. I left it at the dealer for a month, after several 'visits' (off warranty, of course) failed to find a problem. They said it never acted up in that time - but doing a search, found this is a common problem in these vehicles - with variable 'causes'. We got rid of the car.

I had a Holden ute that would very rarely die and then miraculously start again hours later. Looked for all the obvious stuff. An old mechanic said "Do you carry water in the ute with you?" Absolutely. He pointed out the "Dwell angle sensor" on the motor and said Next time it happens, pour cold water on that, cool it down and see if it works. It did. Replaced the sensor, problem solved. It tended to happen when the vehicle was hot. Stop for something briefly, restart and drive a short distance and it would die. I never would have figured it out on my own. JayInOz

[John B]

I had a Holden ute that would very rarely die and then miraculously start again hours later. Looked for all the obvious stuff. An old mechanic said "Do you carry water in the ute with you?" Absolutely. He pointed out the "Dwell angle sensor" on the motor and said Next time it happens, pour cold water on that, cool it down and see if it works. It did. Replaced the sensor, problem solved. It tended to happen when the vehicle was hot. Stop for something briefly, restart and drive a short distance and it would die. I never would have figured it out on my own. JayInOz

Can't say I've ever heard of that particular problem or unit for that matter. Ya wouldn't be laying one of those Aussie drop bear things on us would ya?

[robm]

I had a Subaru Loyale (Leone elsewhere), normally one of the most reliable beasts ever built, with a bad fuel pump relay. Either too much heat or cold would cause it to fail. The car would run like a champ, then not start a few minutes or hours later. Intermittent, of course, and hard to diagnose (the relay was buried under the dash above the steering column - upside down under the dash with the seat laid flat was the best access). For a while, I ran it with a direct connection to the fuel pump, a wire direct from the battery to the fuel pump hot wire, accessible under the back seat that flipped forward (it was a wagon). I wrecked the thing a month after I figured it out and fixed it.

[JayInOz]

Can't say I've ever heard of that particular problem or unit for that matter. Ya wouldn't be laying one of those Aussie drop bear things on us would ya?

Just for you John. There are lots of different models sold as crank angle sensors, but the feller who put me onto it called it the dwell angle sensor. The dwell angle refers to the points and there is a tester available for it.

https://www.ebay.com.au/itm/40363044...IaAkXOEALw_wcB

https://www.ebay.com.au/itm/17541675...Bk9SR5TMpKC1YQ JayInOz

[Bob (oh, THAT Bob)]

If not already mentioned: Worn starter motor brushes. Try turning key with someone tapping on the starter motor with a rubber mallet. If remedies, replace starter.

[John B]

Just for you John. There are lots of different models sold as crank angle sensors, but the feller who put me onto it called it the dwell angle sensor. The dwell angle refers to the points and there is a tester available for it.

https://www.ebay.com.au/itm/40363044...IaAkXOEALw_wcB

https://www.ebay.com.au/itm/17541675...Bk9SR5TMpKC1YQ JayInOz

Thanks Jay, most I've played with on modern stuff is induction and exhaust sensors.

[George Jung]

when my van 'died' - it was dead. All of it. Radio, lights, etc. And after a day - all functioning. The dealer/mechanic called it a ghost. If it had been acting up when they had it - might've figured it out. But after towed, it was functioning again. I no longer have it - but I'm still curious.