GMT-900 Won't start when hot

[Triki_Dick]

I have had this problem for a long time, but it has never bothered me until lately.

 

During the winter, I have no issues, but the summer is a different story.

 

New battery was my first step, installed a Gel Red top.

 

Get in, drive, enjoy your ride but when you get to your destination turn off the truck and BOOM, your screwed. I usually wait about 15 minutes and when I turn the key the truck starts like nothing is wrong.

 

Usually, what I do is get mad, and rattle the battery, and that has made it start. Usually, just opening the hood and cussing has made it start, but that doesn't always work. Well, I just crawled under the truck and took the starter loose in hope I would find a loose connection on the starter. It was tight.

 

For some reason, I have heard a tick, and after it ticks the truck will start. The tick sounds to be coming from close to the battery bay, but I am not sure.

 

So, I wait until it cools off, and it will start right up and drive.

 

Any advice will be appreciated.

[Triki_Dick]

I have been thinking about this, and I think this may of been a common thing because there is a heat shield over the coil (I think that's the correct name).

 

I took the starter off, and checked the connections, however the exhaust is 2" from the starter, so obviously the heat from the exhaust is effecting the starter.

 

Thanks to the people who have viewed this post, hopefully I can find a solution.

[intheburbs]

You have to be more specific about "not starting." No crank? Crank but no fire? Crank, partial fire, but doesn't completely catch?

 

Since you're talking about the starter, I'll assume you get no crank when it's hot. Do other electrical systems work? If you turn on the ignition when it's hot, but not try to crank it, does everything power on as it should?

 

My first guess would be a loose connection somewhere. Check all of your cables.

[2018GMC]

Could be a relay going bad.

[Supreme Pizza]

Starter overheating?

Defective relay?

Automatic engine shutdown system engaged?

 

You could test the starter by hot wring it directly to the battery ( I dont have the procedure, maybe jumper cables, screw driver etc)

 

Opening the hood will allow cold air to rush up from under the motor as the heat rises out from the engine compartment. This could cool off the starter, relays etc.

[repairman54]

Keep your VOM with you to check voltage at the battery to verify if battery or cables.

Hot starter fails don't fix themselves by rattling the battery.

Check voltage drop from battery to starter, I've had bad cables that look like new on the outside causing erratic starts.

I've had 3 batteries in the last 12 yrs , all in warranty, fail due to internal connection problems causing erratic starts. Those were the fails that wacking the battery made the headlights come back on and it starts. In 2 different vehicles BTW.