Hot starter motor
 

How would my starter motor act if it was getting overheated by my headers.

Re: Hot starter motor
 

It would drag and crank real slow.
Or not even work at all.

Re: Hot starter motor
 

Would it seem like my battery is low and possibly drain the battery? Would it work fine once it cools down? My minnie starter is about an inch from my header. Is that close enough to make it hot? My truck is having a hard time starting when it is hot. When it does this it gives the impression that the battery is low but it’s not. The voltomiter reads above 12 volts before I try to crank it over. While cranking it drops to almost 0. After it has started it has around 14 volts. Should I try and wrap it in some heat shielding?

Re: Hot starter motor
 

Yup! Feels like a low battery.
And starts good after a cool down is normal.
Try some header wrap.
Check all your grounds are good too. Run an extra couple grounds from the motor to the frame too.

Re: Hot starter motor
 

Yes to all your questions.
Try a heat shield for your starter and some header wrap.

Re: Hot starter motor
 

Great thanks guys

Re: Hot starter motor
 

You might also want to check your timing, if set too high it will make it hard to start when hot.

Re: Hot starter motor
 

That was my first thought. I have been though that already including a new carburetor. I don’t think that will explain the slow turning starter motor. Thanks for the advice though

Re: Hot starter motor
 

I wouldn't assume heat first for a slow crank--then again I'm sort of an electrical geek so I go to the wiring/battery. >12V isn't accurate enough to say the battery is charged. Slow cranking can be caused by not so great wiring between the battery big cables and the starter. Burned contacts in the solenoid sometimes create resistive connections.
People always babble about heatsoak when the issue is generally electrical. But no one wants to troubleshoot.

Re: Hot starter motor
 

My headers never seem to overheat my starters. I can roll down the interstate at 3k rpm for 2 hours, pull into a rest area or gas station for 5 minutes and it always fires right up. In 30 years I could never get a starter to overheat next to headers. Maybe stop and go city driving makes them hotter than interstate driving or rural driving.

Re: Hot starter motor
 

How old is the starter, the stock GM starters wear out the bushings at either end which cause issues as well.

Re: Hot starter motor
 

Its an aftermarket mini starter. It is probably around 5 years old but hardly used in those 7 years.

Re: Hot starter motor
 

This may sound odd but carry a gallon of water with you. The next time you suspect a hot starter dribble the entire gallon down the back of the head so it lands on the starter If it fires up you'll have your answer.

I had an 86 that did this in the summer and it started every time I poured water on the starter, and it happened several times while I owned the truck. I even tried a heat shield but it didn't solve the problem and I don't think I ever got more that a year or so out of a starter, but the first one I bought had a lifetime warranty from Autozone. Since I never knew when one was going to fail it was a PITA problem but they always gave me a replacement.

One other suggestion: If it's not the starter pull the dist cap and make sure the mechanical advance isn't getting stuck.

Re: Hot starter motor
 

The voltometer reads above 12 volts before I try to crank it over. While cranking it drops to almost 0. After it has started it has around 14 volts. Should I try and wrap it in some heat shielding?

This statement you made most likely tells you whats wrong . A battery can read 12.5 volts and still be bad . The plates in the battery sulfates and will not let the current thru them but still show good voltage . The test you did tells you this under load . A battery should not drop voltage that far when cranking . A couple volts at the most if that . Your battery is not up to the task . The 14v tells you the charging system is doing its job . This does not mean the battery is doing its job .

When a electric motor , in this case is the starter gets hot they are less efficient and will not start up under heavy loads when hot when the current is not there to draw from . When cold they may do fine but most likely is on the edge .

Get a new battery regardless . You need to resolve this before going any further . You will be chasing your tail .

Re: Hot starter motor
 

2nd on check the battery. For reference, the Cold Cranking Amps number on a battery is the number of amps it can provide for 30 seconds while at 0 degrees F and maintain a voltage of at least 7.2.

Sounds like yours is going to near 0v far quicker then 30 seconds while much warmer then 0F. This assumes you are measuring volts directly off the battery. Reading a factory volt gauge isn't the same.

Would also be a good time to check/replace the battery cables. They can look good on the outside and be toast on the inside.

Re: Hot starter motor
 

Mine did the same but it was the dist. had slowly walked , wasn,t quite tight enuff

Re: Hot starter motor
 

Brand new battery, cables and wiring harness. If it is not the starter motor than there must be something putting a strain on my battery when cranking.

Re: Hot starter motor
 

I'm with the electrics camp.

If you're starter is 1" from the tubes the solenoid and it's connections are likely getting a bunch of heat as well. Check the power cable here. I'd replace it with a well heat shielded and routed new piece now that the old one has been heat cycled up next to the tubes unshielded ( assuming no shielding ).

Battery first though methinks. Or just borrow a load tester and put the battery to the test ( take it to local parts house and they'll load test it ).

Hth,

-klb

Re: Hot starter motor
 

The battery already failed the poor man's load test.

Re: Hot starter motor
 

I was having this problem before new battery and after new battery so we can scratch that one of the list. There might be something causing the battery to drain quickly and only have enough energy to start the truck when cold.

Re: Hot starter motor
 

next time it does it, unplug the power to the distributor and see how fast it turns over. If it spins over better then you know it’s too much initial timing and you’ll also know that your starter, battery, cables and grounds are all good.

Re: Hot starter motor
 

Thanks I will give that a try. I was going to try the poring water on it to see if it cools it down and see if that helps idea but I will try yours first.

Re: Hot starter motor
 

Water has it’s uses but not for pouring on hot parts.
The thermal shock will crack cast iron starter noses.
And create an excellent ground path for your 12v power supply on the starter.
If you want to cool the starter you can use a wet cloth on it.

Re: Hot starter motor
 

I think the term was dribble!!


-klb

Re: Hot starter motor
 

So I did some testing today. Gadge showed 12 volts. Started the engine cold and the gadge went down to 0 while tuning it over and started right up. Went for a long drive and got it nice and hot. The gadge was showing 12 volts with engine off. I tried to start it up and it dropped to 0 volts and struggled to turn over. So I unplugged the distributor and it turned over fine. Then I plugged the distributor back in and it turned over fine again. I’m guessing that that means it’s not the starter motor getting hot. I have an emergency cut off switch between the battery pluss and the starter motor could that be causing a problem?