When hot, No start

[FRANKIE TOO]

After driving my 79 vette and the engine is hot.. It has a tendency to not crank..
Turn the key and absolutely nothing happens.. No click, no crank. nothing.. It does start after sitting roughly 15 or so minutes. I assume that it is cooled off a bit... ANY SUGGESTIONS..
Thanks Frank

 

[joe paco]

After driving my 79 vette and the engine is hot.. It has a tendency to not crank..Turn the key and absolutely nothing happens.. No click, no crank. nothing.. It does start after sitting roughly 15 or so minutes. I assume that it is cooled off a bit... ANY SUGGESTIONS..Thanks Frank

the "click" you (don't) hear is the solenoid terminal putting current through the coil, that then magnetically pulls the starter plunger into the case of the solenoid, in the process pushing the pin that forces the copper washer into contact with the copper lug nut -connected to the positive battery terminal, and with the starter motor connector, all at the same time. if all that works correctly, the mechanical coupling activated by the solenoid pushes the starter clutch/gear into the flywheel as the starter motor turns.

when you don't hear any of the two clicks, the solenoid coil has not been energised, either solenoid defective or start circuit open. (you probably already knew all this.)

in simpler times, the ignition switch sent the voltage to the solenoid with one -usually purple- wire, now I believe it goes to a starter relay, also is in series with the neutral safety switch. of course, VATS on later models.

first thing to check is the neutral switch or clutch switch, also starter relay, if it has one. not familiar with that component, yet. not sure how heat effects this.

last time I had the same symptoms, it was an 82 el camino, and the purple wire was high resistance at the solenoid terminal, loose and corroded. if you could get to the solenoid, you could apply a jumper (or screwdriver) from the battery cable end at the starter to the solenoid terminal. if it activates solenoid, the supply circuit is open. if it does not, solenoid is defective, open wire, whatever.

narrows it down, but no solution.

 

[JohnGrawcock]

Sounds like the solenoid is getting too much heat from the exhaust. Are you missing a heat shield or running headers with no heat shield between them and the starter?

 

[joe paco]

Sounds like the solenoid is getting too much heat from the exhaust. Are you missing a heat shield or running headers with no heat shield between them and the starter?

John, from my experience with coils, small motors, etc, the heat causes more permanent issues, example, the plastic coating -mylar, in appliances- melts off the bare wire(s), and can cause the device to fail. The heat in itself causes higher resistance, but not failure intermittently. Sounds almost like a protector, or relay, tripping out, not resetting.

of course, the 79 does not have these.

one could install a separate wire from solenoid terminal purple, to proximity of positive wire on battery to connect the solenoid manually. if solenoid engages, the circuit is open elsewhere.

saludos, joe

 

[6880 Mike]

...Sounds like the solenoid is getting too much heat from the exhaust. Are you missing a heat shield...

I agree. Heat soak. My '74 would do it on occasion.

 

[Vette D.R.S.]

I agree. Heat soak. My '74 would do it on occasion.

I concur, you can put a relay setup on it that helps to eliminate this...Painless Performance: Hot Shot Kit

Your Solenoid just may be giving up the ghost.

I have used this kit on other projects, especially big motors, headers and a tight engine compartment.

Hope this helps


Dave

 

[joe paco]

I concur, you can put a relay setup on it that helps to eliminate this...Painless Performance: Hot Shot Kit Your Solenoid just may be giving up the ghost.I have used this kit on other projects, especially big motors, headers and a tight engine compartment.Hope this helpsDave

his solenoid is not even clicking, which should require less than 12 v. that kit "jolts" it with higher voltage, if i read it right, but the starter still uses battery voltage. Sounds like it attacks the symptom and ignores the root cause. I never saw a dead solenoid that came back to life. Something changes other than heat loss in the windings, either voltage at the sol terminal or ground path.

without some minimal diagnosis we're all shooting arrows at a moving target, over a high fence, in the dark.

saludos, joe

 

[Vette D.R.S.]

his solenoid is not even clicking, which should require less than 12 v. that kit "jolts" it with higher voltage, if i read it right, but the starter still uses battery voltage. Sounds like it attacks the symptom and ignores the root cause. I never saw a dead solenoid that came back to life. Something changes other than heat loss in the windings, either voltage at the sol terminal or ground path.

without some minimal diagnosis we're all shooting arrows at a moving target, over a high fence, in the dark.

saludos, joe

So is said, I doubt he has his ear to it, ha ha just kiddin, when there is heat soak you won't hear any noise sometimes, the plunger cannot move, due to the expansion and or the close tolerances caused by the heat, let it cool and it contracts and then it can move or start to move, that is when you will hear the click..... but I agree completely as I said above that the solenoid or even the starter itself may be marginal, the starter itself could have a bad or severely worn bushings causing the armature to drag on the windings, solenoids they will work sometimes and not another depending on the severity of the heat soak,the heat soak when it is not extreme you will hear the clicking of the solenoid.
But you must understand and diagnose the system not just throw parts at it.



Dave







Dave

 

[joe paco]

So is said, I doubt he has his ear to it, ha ha just kiddin, when there is heat soak you won't hear any noise sometimes, the plunger cannot move, due to the expansion and or the close tolerances caused by the heat, let it cool and it contracts and then it can move or start to move, that is when you will hear the click..... but I agree completely as I said above that the solenoid or even the starter itself may be marginal, the starter itself could have a bad or severely worn bushings causing the armature to drag on the windings, solenoids they will work sometimes and not another depending on the severity of the heat soak,the heat soak when it is not extreme you will hear the clicking of the solenoid.But you must understand and diagnose the system not just throw parts at it.DaveDave

may be right. my experiences were in the sixties and seventies, long before you were born, but my mind is open to new ideas. things change in designs. the starters I rebuilt had a plunger that was rather loose in the solenoid case. I was not aware that '79 Vettes had heat shields until now. my '91 does not, best I can recall from being under it.
in all my life, if I ever encountered a heat soak issue, I was unaware of it. I will be tickled to hear that a heat shield cures it, but I doubt it will.

peace, y saludos

 

[Art Jett]

may be right. my experiences were in the sixties and seventies, long before you were born, but my mind is open to new ideas. things change in designs. the starters I rebuilt had a plunger that was rather loose in the solenoid case. I was not aware that '79 Vettes had heat shields until now. my '91 does not, best I can recall from being under it.
in all my life, if I ever encountered a heat soak issue, I was unaware of it. I will be tickled to hear that a heat shield cures it, but I doubt it will.

peace, y saludos

My experience with this was also from the 60's. My brother had a 58 that after driven till it got up to normal operating temp, if shut off wouldn't start till cooled off. No audible click. I drove it on more than one occasion and always made sure not to shut it off unless I was going to be there for a while. Went through a few starters and always the same problem. The car didn't have a heatshield for the starter. Art

 

[joe paco]

My experience with this was also from the 60's. My brother had a 58 that after driven till it got up to normal operating temp, if shut off wouldn't start till cooled off. No audible click. I drove it on more than one occasion and always made sure not to shut it off unless I was going to be there for a while. Went through a few starters and always the same problem. The car didn't have a heatshield for the starter. Art

the one thing we know, Art, is that NO ONE knows what the problem is, since the poster has not communicated anything. I read dozens of comments on another forum, half of them said the shield was not the "likely" root cause, citing high resistance in battery cables, high resistance in ground straps, loose conection on solenoid.

my logic says that hundreds of thousands of Vettes are without the heat shield and don't have the problem -especially at 'operating temperature.' what's the probablility of getting 3 defective starters, all failing the same way, "heat sink," on a stock '58 engine? pretty remote. why don't 100% of Corvettes fail?:confused

"after this, therefore because of this" is a common fallacy. I've made the mistake many times. we change so many things in the process, grounding, for one, we miss the one root cause.
just call me skeptical.

saludos, joe

 

[JimVette]

Years ago I had a '66 327/350 and starters would last about 6 month. I finally went to a reliable shop that specialized in rebuilding starters and alternators and they rebuilt the starter for a high compression engine. The starter was still on the car ten years later when I sold it.

 

[Bow-Tie Guy]

If I may add to the discussion, in terms of the original post, I had similar problems and after replacing every component (new starter, new alternator, new wiring harness, new heat shield, etc...), I still had a problem with starting. In fact, the problem grew over time from just not starting while hot to intermittent not-starting at all!

Thanks to this forum, I finally tried the most simplest possible solution that "I knew for certain wasn't the problem" because I was too lazy to get under the car - cleaning and reattaching the ground strap from the battery to the frame!

It's been five months now with absolutely no "starting or battery" problems. Sometimes when you hear galloping hoofs, they're just horses - and not zebras...

If you haven't yet, try checking the ground straps - what can it hurt?

 

[bb2kksy]

Had the same problem with my 79. Turned out the connections on the starter got loose when it was hot. Pulled them down and now all is well.

 

[Art Jett]

my logic says that hundreds of thousands of Vettes are without the heat shield and don't have the problem -especially at 'operating temperature.' what's the probablility of getting 3 defective starters, all failing the same way, "heat sink," on a stock '58 engine? pretty remote. why don't 100% of Corvettes fail?:confused

saludos, joe[/QUOTE]


I never said it was a "stock" 58 engine. It was in fact a pretty hot 327. After changing multiple starters, battery cables and ignition switch, we finally put a shield around the starter between it and the headers, and never had the problem again. Art

 

[joe paco]

Art, my mistake, I assumed the engine was stock. Headers make a big difference in heat, because of how they are routed, plus they probably carry more heat further.
I never had or heard of an issue with headers, in Camaros, Chevelles, '55's. I reckon an inch of space makes a big difference in heat dissipation. For stock engines to suddenly be failing for starter " heat sink," in the manner described, does not make sense logically, which was my point, unless other factors are in play.

If the heat shield alone resolves it -without touching connections, whatever- I'd say that heat was the major contributor. Freddie too can easily make one out of a couple of beer cans.


saludos, joe

 

[BankOfHell]

I had the same problem when I went to an electric radiator fan--higher underhood temps I guess. It got so bad I kept a 1/2 gallon of water to dump on the starter so I wouldn't get stuck waiting for it to cool down. Installed a high torque starter and no more problem.

 

[nada1]

I had the same problem when I went to an electric radiator fan--higher underhood temps I guess. It got so bad I kept a 1/2 gallon of water to dump on the starter so I wouldn't get stuck waiting for it to cool down. Installed a high torque starter and no more problem.

"there you go again!" -ron reagen

I guarantee you are correct. but...the one root cause was aggravated by the heat; high resistance in wiring, grounds, whatever. otherwise, evey similar model on the road would do the same thing.

there are GM tech bulletins on the CC site above. four of the (C4) "no start hot" problems were high resistance, not heat migrating into the starter/solenoid. one was simply black paint on the starter mounting surface on the block.
whoda'thunkit?

jc

 

[wildcard]

After driving my 79 vette and the engine is hot.. It has a tendency to not crank..
Turn the key and absolutely nothing happens.. No click, no crank. nothing.. It does start after sitting roughly 15 or so minutes. I assume that it is cooled off a bit... ANY SUGGESTIONS..
Thanks Frank

I am having the exact same problem with my 78. But iv noticed that when it will not turn over the lights in the car still work. And if I get a jump it starts right up so I am guessing it is the grounding wires. I am going to fix them tomorrow and see how it goes.

 

[mkapp7879]

Take the starter off and remove the solenoid.
Carefully remove the plastic cover and you'll see the edges of the disc are burned.
Wire brush the burn marks off and turn the contact in the cover 180* so you have a new surface(see the pic).
Should fix the problem.