[Fullback66]

I have been having problems with battery heat soak on my stock 389 66 gto. On a hot day of driving. Turn car off. Minutes later try to start it and very slow crank. It's not the battery.
Question:
Any one else have this problem?
What did you do to fix this?
Does a starter wrap work for this?
I appreciate any help.
Thanks FB66

[Fullback66]

Not battery heat soak.
Starter heat soak.
Sorry about that
FB66

[thepontiacman]

Put heavy duty solenoid spring in solenoid on starter. A heat shield over solenoid helps also.

Check all connections for corrosion.



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[Stuart]

A shield can help but if everything is stock there shouldn't be an issue with starter heat soak. As mentioned, make sure all connections are clean and tight, also check to see if the starter bearings and brushes are worn. Those parts should still be readily available and are pretty simple to replace.

[Cammer-6]

if in doubt change to the hi temp starter from a 500 Caddy
I dont remember if you need to change the nosecone or not.
easy to spot the distance from solenoid bolt for windings is different.
Cables can appear ok but be full of corrosion under the insulation

[Greg Reid]

I learned something a couple of years ago for the first time after years of chasing that problem on various Pontiacs. Make sure that the ignition switch wire going to the 'S' terminal on the starter is getting at least 9 or 10 volts at the solenoid. I know it's not easy to do in a parking lot but if you can pre-rig a jumper from the 'S' terminal to someplace you can get to it you may find that only 4 or 5 volts is present there when it refuses to start.
That purple wire can get baked and develop high resistance after a few decades. I spliced a new wire from the firewall to the starter and it never happened again. I didn't have to pull the ignition switch but you could do that and replace the entire length.

[OCMDGTO]

For me the cure was getting new 1 guage battery cables(American Autowire). I also put a heat shield on the positive wire.

[RedDirtRoad]

I had my original starter rebuilt by a local guy and he told me a trick which seemed to work
If you look at the start motor case you will see a seam in it. Tack a few mug welds down that seam before installing it
He told me since Pontiacs run hot that seam expands and you don’t get the correct armature clearances
Tacking the seam prevents it from expanding
I did not have a hot start problem after doing this

[george kujanski]

I'd say slow cranking is an issue of the battery/cable/starter rather than a solenoid issue directly. The function of the solenoid is to make the electrical connection between the cable and the starter while driving the pinion out to mesh with the ring gear.

There may be an issue with the contact in the solenoid if it is burned or corroded, i.e. poor electrical contact, or a poor solenoid circuit, not making a good connection in the solenoid. Internal poor connections in the starter, brushes and commutator may also be a problem.

I'm not a fan of starter insulation as that also may prevent the starter from cooling off. If headers are used, header insulation may be a better solution for that.

In my case, the cooling system keeps the engine at normal temps; I have a FORD-style starter relay and 2 Gauge battery cabling; std exhaust manifolds. No hot start issues.

George

[Fullback66]

Originally Posted by Stuart

A shield can help but if everything is stock there shouldn't be an issue with starter heat soak. As mentioned, make sure all connections are clean and tight, also check to see if the starter bearings and brushes are worn. Those parts should still be readily available and are pretty simple to replace.

Thanks for the information!
FB66

[Fullback66]

Originally Posted by Greg Reid

I learned something a couple of years ago for the first time after years of chasing that problem on various Pontiacs. Make sure that the ignition switch wire going to the 'S' terminal on the starter is getting at least 9 or 10 volts at the solenoid. I know it's not easy to do in a parking lot but if you can pre-rig a jumper from the 'S' terminal to someplace you can get to it you may find that only 4 or 5 volts is present there when it refuses to start.
That purple wire can get baked and develop high resistance after a few decades. I spliced a new wire from the firewall to the starter and it never happened again. I didn't have to pull the ignition switch but you could do that and replace the entire length.

Thanks!

[bdk1976]

Do you care what it looks like? If not - Mini starter with 1/0 battery cable and quality terminals.

[Fullback66]

Originally Posted by OCMDGTO

For me the cure was getting new 1 guage battery cables(American Autowire). I also put a heat shield on the positive wire.

Good idea.

[Fullback66]

All very good ideas! Thank you so much!
FB66

[leeklm]

Originally Posted by bdk1976

Do you care what it looks like? If not - Mini starter with 1/0 battery cable and quality terminals.

Unless going for an oem look, I have no desire to install a full size starter. The mini starters are soooo much easier and work great!

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[Fullback66]

One guy I talked to said that my timing could be too much. Any one hear of this?
FB66

[Greg Reid]

Sure. If the timing is too far advanced it can cause pre-ignition and fire when the piston is on it's way up. More of a draggy symptom. Since you say you have a very slow starter action as opposed to NO starter action it could be something to look at.

[Cammer-6]

Originally Posted by Fullback66

One guy I talked to said that my timing could be too much. Any one hear of this?
FB66

pull the coil wire and crank and see if it changes

[Sirrotica]

More than once I have repaired cars with this symtom by not doing anything to the starter, or the positive cable.

Take the ground cable off of the engine and look carefully at it. Many times it will loosen up, or corrode with rust at the head bolt connection. Remember that the positive side has to be in good condition, but so does the negative path back to the battery. The negative cable connection can look perfect by just glancing at it, but when you disassemble it you might be in for a surprise of a high resistance corrosion that is undetectable without removing the nut from the head bolt. When the connection gets hot from engine heat, and expands it will make higher resistance. You'd be surprised how many times people overlook the negative side of the system when hunting hot start problems.

There should also be a star washer to promote a good connection between the bolt and the cable, sometimes it gets discarded when the negative cable gets removed, and replaced.

[60sstuff]

Originally Posted by Sirrotica

More than once I have repaired cars with this symtom by not doing anything to the starter, or the positive cable.

Take the ground cable off of the engine and look carefully at it. Many times it will loosen up, or corrode with rust at the head bolt connection. Remember that the positive side has to be in good condition, but so does the negative path back to the battery. The negative cable connection can look perfect by just glancing at it, but when you disassemble it you might be in for a surprise of a high resistance corrosion that is undetectable without removing the nut from the head bolt. When the connection gets hot from engine heat, and expands it will make higher resistance. You'd be surprised how many times people overlook the negative side of the system when hunting hot start problems.

There should also be a star washer to promote a good connection between the bolt and the cable, sometimes it gets discarded when the negative cable gets removed, and replaced.

This ^^^^ is absolutely true.