I dont know if u have headers and what your heat shield looks like. But the heat sheild needs to provide an air space/gap between the shield and the solenoid & starter motor. Heres a link to a pic of mine and if the link is not direct u may have to scroll through the pix to find the starter shield pic: http://www.cardomain.com/ride/445470...olet-corvette/.

Dont try the remote solenoid install. Fords use a remote solenoid because theres not one mounted on the starter. Ford starters also have permanent magnets which are moved as as the motor is energized and push out the bendix gear - chevy doesnt use permanent magnets. If u install a remote solenoid on a chevy the original solenoid remains there and still does the work of throwing out the bendix gear and energizing the starter motor. Anyone that installs a remote solenoid on a chevy starter knows nothing about electrical wiring and solenoids.

U say u replaced all the cables when u bought the car but no one knows how long ago that was. If it was years ago u should verify low resistance again - all starter associated wiring.

I tried a GMPP mini geared starter as u can see in my link if u look through the pix and i just could not get the bendix gear to line up so it still sits in storage. But with the heat shield i modded and installed the stock starter works - i'll even say "flawless" - in Nevada triple digit temps w/headers to. FYI JC Whitney doesnt sell that shield anymore (a shame at like 10 bucks) but u could search the net for something similar.

I really like my 4th Gen Z28 starter but its for 153 tooth flywheels - dont know what u have. Take a look at AC Delco starters: Part Number: 323-480 Years: 1993-1994

Part Number: 336-1580A, Family DE-PG250, Unit MFR DE ; kW Rating 1.4, Drive PMGR ; 336-1580A; 6Y2, 0050A, Years: 1993-1994.

Hope this helps.

 

So I guess I dont know what I am doing, or the Chevy engineers who put together a parts kit/TSB to add the second "Ford" type solenoid to the starter circuit. It was a factory/warranty repair for "heat soak". I have been using them for years. If you don't need it, great, no need to over complicate a circuit. But it does work.

That said, from the OP's posting, I dont think that is what is needed here. He said the starter would spin - but slowly. That would not be a symptom of solenoid heat soak, where the starter does nothing or only has a click from the Bendix. It sounds like not enough current/voltage supply. Your comment about checking cables and connections sounds on point. Also a good tip on the later model starter.

Back to the second solenoid - Forgive me for not knowing how this works, but here is my uninformed opinion. The Chevy solenoid supplies mechanical movement as well as electrical contact connection. The heat from it's location can cause added electrical resistance and expansion. The second solenoid takes the original switching voltage and uses it to only switch power to new LARGER wires with DIRECT connection to the battery. By now having FULL voltage, and AMPLE current, the Chevy solenoid is more likely to overcome any heat associated resistance (electrical or mechanical). A weaker return spring on the plunger was also a fix for heat issues. As these cars age, resistance can increase because of all of the switches, connectors, and wiring aging.

 

If they recommended using a "Ford" type {remote} solenoid, then the SOLENOID is what is failing under heat...NOT THE STARTER.

These 'new' aftermarket solenoids are NOTHING like the original units supplied by GM. They have small awg wire, which is not made of copper. Don't expect a $10 POS solenoid to operate like a $40 "good" one. If someone has an original solenoid, it is best to REBUILD the original, rather than replacing it....even if the cost to do either is the same!!

 

So I guess I dont know what I am doing, or the Chevy engineers who put together a parts kit/TSB to add the second "Ford" type solenoid to the starter circuit. It was a factory/warranty repair for "heat soak". I have been using them for years. If you don't need it, great, no need to over complicate a circuit. But it does work.

Back to the second solenoid - Forgive me for not knowing how this works, but here is my uninformed opinion. The Chevy solenoid supplies mechanical movement as well as electrical contact connection. The heat from it's location can cause added electrical resistance and expansion. The second solenoid takes the original switching voltage and uses it to only switch power to new LARGER wires with DIRECT connection to the battery. By now having FULL voltage, and AMPLE current, the Chevy solenoid is more likely to overcome any heat associated resistance (electrical or mechanical).


I dont know what this parts kit looks like but vendors will sell u anything u want for $$$ - including GMPP. If u do know anything 'bout electrial wiring all u have to do is draw the circuit with the added solenoid. U will see the original solenoid is still there and still has to throw out the bendix gear while its just as hot and heat soaked as ever. All the added solenoid can do is add more resistance and voltage drop. And so u can find posts that say the remote solenoid is a fix or has been a fix but it physically cannot be true - owner remains in denial and cant look at it objectively. If the owner does admit there is still a problem he will usually blame it on another/new issue in the start circuit.

The analogy the new larger wires reduce resistance or increase voltage is false as its not the batt cables or starter hookup wires that are the resistance making voltage drop - its the windings in the solenoid. The large number of small diameter solenoid windings have a positive temp coefficient that increases resistance as temp increases while it has to throw out the bendix gear at one end and close the contactor to power the motor at the other. If u think adding additional wiring (whatever size) and additional contacts (inside the added solenoid) to the circuit reduces resistance and increases voltage to the stock solenoid that does all the work im sorry but u dont understand electrical power. U need to study some basic electrical power fundamentals and stop circulating misconceptions. I can read u feel strongly about this and many others (well respected here too) are convinced as u are. But i have to take a stand here on myth and let truth take its course. I read too many owners are frustrated, then mislead and my conscience just wont let me ignore this.

 

Sorry Cardoo.
The added relay eliminates the voltage drop across the starter switch and the neutral safety switch, increasing the voltage to the existing starter solenoid.(The service bulletin was well thought out, and is accurate, although patch work at best. The brown high temp solenoid was the proper cure, although lost to obscurity).
This is the same cure for the weak headlight switch contacts and dimmer switch. I have installed that mod for many folks, and it does increase the voltage to the headlights, and allows more current to flow, brightening the headlights considerably.

 

one thing a lot of people don't realize is that the solenoid actually has 2 coils in it, one to move and one to hold. cheap solenoids have weak hold coil wire, and even though the starter gear engages, there isn't always sufficient power to hold the switch that completes the motor circuit. there are 4 things going on in there, main coil, secondary coil, resistance bypass terminal completion, and motor circuit completion.

add to that the poor quality of many solenoids with poor fitting terminals in the housing where the switch moves, cheap, non copper/poorly stamped steel/fitting main contactor, and you don't get enough power to bypass the main coil to hold while cranking, resulting in not enough power to spin over a hot motor. bad grounds (not just the cable, the starter and solenoid itself) compounds the problem.

next time you replace your starter, take the solenoid off and tear it apart. I'll bet you'll be surprised and the bad condition of the plunger/contactor and terminals.

you used to be able to get rebuilt solenoids but haven't seen them in years. I have a stash of old solenoids I scam for parts occasionally. the old plastic ends were molded much better than the new plastic ones. the old bakelite ones are the best...

 

I must not have been clear in my description. I am not talking about buying some of-the-shelf parts kit, although you can buy them.
I am talking about Chevrolet engineers designing this fix and dealers installed the second solenoid as warranty work in the 70's. It was a Technical Service Bulletin to remedy the hot start solenoid problem. That is the "parts kit" I was referring to. I am not circulating misconceptions, it works, is proven, and was endorsed by Chevrolet. I am not saying everyone needs one, on the contrary, in the OP's case I would say no. And yes, I also have respect for Noonie.
You seem to not realize, that in some cars, the long path through the wiring harness, bulkhead connectors, ignition, clutch, neutral safety switch, and back to the "S" terminal can cause voltage drop. There can also be reduced current carrying capacity. This is not myth, and can be proven. As the car is used and with age the problem can be exacerbated. The second solenoid can provide full voltage and current capacity to the original solenoid where this is the case.

 

I dont have time for this now. The contact resistance of the wiring connects are not the problem. And since i cant see what is really bypassed by a remote solenoid i cant make assumptions as to what gets bypassed. But i know if u add a solenoid u add a least 1 more contact and more likey 2 contacts as the batt cable is normally rerouted. FYI voltage drop from contact resistance is something like 0.1V so it would take something like 10 contacts to lose just 1 volt.

What u (and others) fail to realize is the problem causing the heat soak is the large number of fine wires wound inside the solenoid. The increase in temp of the small dia wire kills current flow - not the contact resistance that works very well at low temps. Terms like current, positive temp coefficient, magnetic induction, magnetic permeability are just words to u as if u did understood those concepts u could see a remote solenoid doesnt diminish that coil heat soak issue at all - it still there just as before.

Cant speak for these Tech Service Bullets but if u can post one with a drawing also i will look at them when i have the chance.

I think i recall Noonie was a fairly knowledgeable guy. Dont know what your referring to.

Good night.

 

What happened in my case was that when the ignition switch is worn as mine was it would not pass enough current to pull the starter starter into gear. It mostly did this when the engine was hot giving me the impression that the starter was heat soaked. Easy to verify if this is or the neutral switch is the problem by "jumping" the connections at the starter solenoid. If the engine cranks as normal the problem is in the start circuit and not the starter or its solenoid

 

The part that may be confusing is that you are NOT adding a contact per se, you are eliminating 4 contact points.

https://www.corvetteforum.com/forums...post1590260819 Post#7

 

re-read the diagram I posted in your link, you are not eliminating anything. you are adding a switch further up with thicker wire. the contacts in the original solenoid are still in play.

 

Perhaps a poor choice of words then.

You actually are "converting" the ignition switch and neutral safety switch to a control circuit.
They operate the added starter relay, which uses a much shorter, more direct path to the existing starter solenoid from the source.

 

Ok i read those tech bullentins. Just doesnt touch with reality. Says 4 volts can be lost between start switch and solenoid. Well da, that would prevent starts even when cold. And as "hot start" and "heat soak"occured from the tri fives to and including the 4th gen vettes and camaros (probably the B body cars to but who follows those cars). Yes even 4th gen camaros and vettes have the hot soak start problem. Why didnt GM have a fix over 40 years? Because a remote solenoid used on the control circuit is a band-aid fix that would be marginal at best.
On top of that 90% of owners wire the remote solenoid into the starter power circuit like a ford solenoid (spliced into the batt positive cable) and not the control circuit as in the tech bulletin. So that again does nothing for the weak control circuit and nothing for the power circuit either.

Install a good heat shield that reflects exh header radiant heat and allows air to circulate between the solenoid and the shield (motor and shield too) and u wont look back.

 

well, I beg to differ. my C4 vette has never had heat soak. my 68 BB does not have heat soak. my 76 SB does not have heat soak.
in fact, my old 73 Camaro didn't have it. my 77 nova didn't either. or my 79 suburban.

funny how some people think this problem has existed for 40 years with no fix, but the rest of the world doesn't experience it at all. It gets a lot of attention on this forum because these cars are old, but look new, and unlike most other muscle cars that have been restored due to rust and had everything replaced, people think their vette is in great shape when in fact the wiring and connectors are shot...

but at least the mini-starter industry is making money...

 

GM does not issue service bulletins for non existing issues.

Heat soak is real, but NOT common.

My car never gets it. No vehicles I have ever owned got it. However, I have 2 friends that have. Both were BBC Vettes, and one has headers that wrap tight around the starter.

The starter design is very old. I worked on a 36 Buick that had virtually the same starter, and the exhaust was on the other side of the car. GM kept the design, but as the ambient heat evolved higher with BBC's and smaller engine compartments and smog de-tuning, the issue did crop up often enough to issue the bulletin.[ATTACH][/ATTACH]

 

Well thank u, thats an excellent example of "denial". All i had to do was click over to the C4 forum and do a search using "starter hot soak". I get over 150 pages of posts. Not 150 posts but 158 pages of posts. So now u use labels like " but the rest of the world doesn't experience it at all." is flat out denial.

I cant help or even debate with those having that attitude. Its not worth my time or effort at all and i have to leave it as such.

Have a nice day.

 

it's not denial, of those 158 pages of posts, you'll notice my C4 isn't there (nor any of the 5 my friends and family own). I've had it since '99. no heat soak. for real. come over and i'll prove it to you. you're welcome to check any of my vehicles. not denying anything.

as for the rest of the world, or the 158 pages of people you refer, how do you know it's heat soak? Do you know if they have the factory installed heat blanket still on their factory installed LT-1 starter as I do?

As a trained, certified, and decades experienced mechanic, I am qualified to diagnose "heat soak". how many people on these forums do you really think actually know what they are talking about and how to diagnose an electrical problem? a simple perusal of the most common posts and I think you'll see what I mean, too many blaming their problems on heat soak, vapor lock, bad gas, and whatever brand carburetor without really understanding what's going on.

heat soak can happen under certain abnormal circumstances. run cheap headers, overheating engine, high exhaust temps, clogged cat, whatever, but it's not the design that is bad as installed from the factory, nor is it a normal occurrence for every GM top-solenoid starter over the last 40 years...(a design still in use today on current production, btw).

complain all you want, buy expensive mini-torque starters if you want, it's your dime, but I am just trying to help people diagnose the root cause and maybe save them some money.

 

Should I do the Ford solenoid add on?
I keep on hearing it works best. The heat shield with new ground, new starter/solenoid Delco battery doesn't work.
Thanks
Jack

 

Complete waste of time and $$$ - but they will be more than happy to sell you one!!

Best to find and FIX the problem - not bandaide it!