# Hot starting problems



## simmons68 (Dec 22, 2009)

Hey guys,
My 68 GTO will start just fine when it is cold. After it runs for 15 or 20 minutes, it will not start back. It will just make a growling sound, and not even attempt to turn the motor over. I installed a new battery and starter (thought it might be the solenoid). Started just fine cold, then once it got warmed up it wouldn't start. I also installed a new voltage regulator and 2 new ground straps and still will not hot start. Any ideas, I'm lost!


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## freethinker (Nov 14, 2009)

simmons68 said:


> Hey guys,
> My 68 GTO will start just fine when it is cold. After it runs for 15 or 20 minutes, it will not start back. It will just make a growling sound, and not even attempt to turn the motor over. I installed a new battery and starter (thought it might be the solenoid). Started just fine cold, then once it got warmed up it wouldn't start. I also installed a new voltage regulator and 2 new ground straps and still will not hot start. Any ideas, I'm lost!


define growling sound.


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## Koppster (Jul 27, 2008)

Do you have a heat shield on your starter?

If not you might want to purchase one from Ames or Performance Years, pontiac starters are notorious for overheating without the shield.

Rick


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## Koppster (Jul 27, 2008)

$13.00 through PY

Item: RPE670 
Description: SOLENOID HEAT SHIELD
THIS CAN NOT BE USED WITH THE DELCO STARTERS WITH THE SHORT SOLENOID!!! YOU HAVE TO USE THE ORIGINAL STARTER !!! A SOLUTION IS FOR CUSTOMERS TO USE RFE117.

RPE670B recommended for hot starting problems with ORIGINAL solenoids. This shield was originally correct for RA/HO ONLY 


Log On


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## dimitri (Feb 13, 2009)

I was having the same problem with my '68. '68 GTO's never had a heat shield. My problem was the reman starters I was getting from Napa were not done very good. Find a guy in your area that rebuilds starter motors and selenoids. There is a heavier duty spring that this guy used in my selenoid. He also uses a rebuild kits for the selenoid and the starter that are made in the U. S. Also replace your positve battery cable with a new one. Load test your battery. Did you shim your starter motor?


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## geeteeohguy (Feb 2, 2008)

There are numerous Hot Start posts on this forum. Usually the cultprit is high resistance in the circuit from the ign switch to the solinoid (purple wire). Check out the previous posts.


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## BearGFR (Aug 25, 2008)

The infamous hot start problem, almost always caused by the starter getting "heat soaked" from the exhaust. Are you running headers?

There are several solutions depending on how much effort you want to go to and how much you want to spend. Buy (or make your own) heat shield using metal or that reflective/flexible 'heat wrap' material. Another option is an after-market "mini starter", like one of these for example. This one (and others) can be "clocked" - rotated to place the solenoid at the bottom and well away from the heat source, like I did with mine.

Bear


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## simmons68 (Dec 22, 2009)

Thanks guys. I do have full length headers and I will check the other possible solutions you guys gave. I appreciate your help.


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## dimitri (Feb 13, 2009)

Have the headers Jet Hot Coated if they didn't come that way.


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## simmons68 (Dec 22, 2009)

*Hot starting*

Took my battery out and charged it, took it back and the car started up, then when I checked my battery it showed no charge. I drove the car for an hour and killed it. It did start back, but just barely. It made a clicking sound then started slowly. I will check my alternator now, but what voltage should my alternator read??? I think around 13 or 14, is that correct? Thanks for the input.


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## Backup (Oct 16, 2010)

You can check your alternator by using a jumper wire from the "F" post of the alternator (where the plug goes into the back) to hot (I think it's hot, someone correct me if I'm wrong). With a voltmeter on your battery posts and the vehicle running, you should be getting 13-14 volts. no more than 14.2v. If you are getting a reading below 12v with everything hooked up unplug the wire from the alt and use the jumper wire. If the voltage climbs up to an acceptable range then the voltage regulator is bad. 

Before you do any of this, make SURE your ground cable connections are clean and making good contact. My ground cable loosens slightly over time and doesn't allow enough of a connection to recharge the battery properly, but does produce enough that the generator light doesn't always come on. It gives me the same symptoms as "hot start" but is not the same and is easily cured.


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## dimitri (Feb 13, 2009)

Did you load test the battery?


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## simmons68 (Dec 22, 2009)

Checked all of my connections, all were good. Did a load test on the battery and it showed no charge while the car was running. Checked all circuits and all were good. Still stumped. It will start cold perfect then once I kill it, it will turn over about half a turn then just make a clicking sound. If I wait about an hour, it will start perfect again. Stumped??


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## dimitri (Feb 13, 2009)

The only way to check a battery correctly is to have it load tested. Most auto parts stores do this free. 13 -14 volts is good output for the altenator.


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## 68GTO4004Spd (Jun 19, 2008)

A coil that is going bad will give you those symptoms.


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## BearGFR (Aug 25, 2008)

simmons68 said:


> Checked all of my connections, all were good. Did a load test on the battery and it showed no charge while the car was running. Checked all circuits and all were good. Still stumped. It will start cold perfect then once I kill it, it will turn over about half a turn then just make a clicking sound. If I wait about an hour, it will start perfect again. Stumped??


I'm still betting the problem is heat soak from the headers. What you're describing are the textbook symptoms. That's exactly how they act. Starts fine cold, but once the motor has run long enough to get the headers nice and hot, the starter solenoid gets hot and won't work again until it cools off. The cheapest solution is to find a way to shield it from the heat. If you want to 'prove' that's your problem, start it up and let it run long enough to recreate the problem, then set up a fan or something similar under the car to cool off the starter faster than it would by just sitting. I bet you'll find you're able to restart it much sooner.

Bear


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## geeteeohguy (Feb 2, 2008)

I have to agree. On all the hot start problems I've had over the years with Pontiacs, the problem has ALWAYS been high resistance somewhere caused by HEAT. It can be in the purple wire, the neutral safety switch, the battery cable (s) and the SOLENOID. There is a reason GM came up with a heat shield for the starter solenoid on these cars. Since I fixed the bad circuit from my ign switch to the solenoid in my '67, though, I have not needed the heat shield even in the hottest weather. Heat causes electrical resistance to increase, and if any system is marginal to begin with, it will act up when hot.


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## Instg8ter (Sep 28, 2010)

agree with bear and gto, was just reading article on this ....used to know of chevy guys using ford remote solenoids on the firewall/inside fender, anywhere away from the heat, but it would be sacrilege to put a ford part on a pontiac

here is the article, will be doing this before dropping my new motor in, have high torque mini starter with shielded solenoid, and will definitely re-install the cable shield, electric problems suck, ounce of prevention...

"If the starter just grinds slowly, this is a voltage-drop problem. But if you've got the typical GM problem of the starter not engaging properly in a hot-soak condition,the cause is a major voltage drop across the solenoid-engagement circuit. "

http://www.carcraft.com/howto/116_0507_top_10_electrical_fixes/index.html


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## 66tempestGT (Nov 28, 2009)

like the man said. heat shield is a crutch. if your system is up to snuff no shield is needed. or ford solenoid.


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## geeteeohguy (Feb 2, 2008)

Another thing I've found with these cars...(my old top switch two weeks ago, for instance!) is that sometimes the wires will degrade to the point where only a couple of strands are actually conducting electricity.....usually at a connector. You do a voltage check, and it'll read voltage,and you'rr THINK everything is OK, but when you put a LOAD on the circuit, the 2 or three strands can't carry the load.....all 10 strands of wire are needed! Voltage drop testing is excellent to troubleshoot this kind of problem.


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## DukeB-120th (Oct 19, 2009)

geeteeohguy said:


> Another thing I've found with these cars...(my old top switch two weeks ago, for instance!) is that sometimes the wires will degrade to the point where only a couple of strands are actually conducting electricity.....usually at a connector. You do a voltage check, and it'll read voltage,and you'rr THINK everything is OK, but when you put a LOAD on the circuit, the 2 or three strands can't carry the load.....all 10 strands of wire are needed! Voltage drop testing is excellent to troubleshoot this kind of problem.


I don't follow, GeeTee... How does this "voltage drop testing" diagnose the degradation?


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## geeteeohguy (Feb 2, 2008)

If you just check the available voltage at the load, before you activate the circuit, you'll get a "good" reading even with just a couple of strands of wire. If you activate or load the circuit (crank the starter, operate the top motor, etc) with a voltmeter across the load, you can measure the voltage drop (or lack of it) to check for a resistance or continuity problem. For more and probably easier to follow information, google "voltage drop testing".


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## DukeB-120th (Oct 19, 2009)

ah ok that makes perfect sense! Thanks Gee


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## Droach6498 (Nov 1, 2020)

simmons68 said:


> Thanks guys. I do have full length headers and I will check the other possible solutions you guys gave. I appreciate your help.


You might try header wrap at the starter


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