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Heat soak, upgrade starter wires?

Irishmic

Irishmic

1/2 ton status
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I have a 03 5.3 vortec with headers. If i drive it and it gets heated up then stop and turn off it will not want to start Back up until it cools down. However if I try and start it right back up, say within 3 or 4 minutes it will start fine. It's once it no longer get has the air cooling it down and (I think) heats up the starter to the point it don't want to go.

Now if I crank on it and just push it i
can finally turn over but I don't like to and just won't.

Basically when this issue happens if I turn the key and hold it in the start position the whole time it will crank for like half a turn, wait 3 seconds crank like a full turn, 1-2 more seconds a few cranks, then half a second and go into a full start. To do this the key would be held in the start position the whole time. Again, this feels bad and I don't do it as I'm worried to burn out the starter completely. When it's cold it has no starting issues. Really the engine temperature needs to be down to 160, maybe 170 depending on the weather, how much wind that day.

So my ideas are a heat shield, I hear mixed reviews on that. I also hear that this issue can be the current from the battery to the starter itself. I could upgrade the cables and send more current, thus bypassing the drain on power from the extra heat.

Would live to hear people's ideas on this and anyone who has run into this same issue. I just hate not wanting to stop because we'll it may not start back up.
 
To me it sounds like the starter is going out, haven't heard of the LS heat soaking like the 40lb small block starters did.
 
The factory starters have a heat shield on thr solenoid. Does yours? Maybe try that?
I have limited experience with the LS engines, but I haven't heard of them having the heat soak problem.
My '01 2500HD has an LQ9 with a small upgrade in the cam, stainless long tube headers and cranks easily when hot. Factory thermostat temp, A/C and 100* heat, new starter. No problem, only had it a year and a half so far.
 
6872xtc said:
The factory starters have a heat shield on thr solenoid. Does yours? Maybe try that?
I have limited experience with the LS engines, but I haven't heard of them having the heat soak problem.
My '01 2500HD has an LQ9 with a small upgrade in the cam, stainless long tube headers and cranks easily when hot. Factory thermostat temp, A/C and 100* heat, new starter. No problem, only had it a year and a half so far.
Click to expand...


It has no heat shield on it now. It only only happens when it's warmed up. Starts in the cold fine, like 10 degrees and no issue. But when driven and tired to restart, has issues.
 
I'm not familiar with LS engines but used to have same problem on old school SBC. Guys on forum said it was the solenoid heating up and try remote solenoid. I added a Ford solenoid on the wheel well cover and problem solved. I didn't think it would work since solenoid still got hot but it did the trick. Just a thought. Used to be a common mod back in the day,
 
trukman1 said:
I'm not familiar with LS engines but used to have same problem on old school SBC. Guys on forum said it was the solenoid heating up and try remote solenoid. I added a Ford solenoid on the wheel well cover and problem solved. I didn't think it would work since solenoid still got hot but it did the trick. Just a thought. Used to be a common mod back in the day,
Click to expand...

the second solenoid allows more current flow to the starter solenoid actuation coils. More heat demands more current.

If the second solenoid supplies only the start signal, it will work on a permanent magnet ls starter.
 
trukman1 said:
I'm not familiar with LS engines but used to have same problem on old school SBC. Guys on forum said it was the solenoid heating up and try remote solenoid. I added a Ford solenoid on the wheel well cover and problem solved. I didn't think it would work since solenoid still got hot but it did the trick. Just a thought. Used to be a common mod back in the day,
Click to expand...
Same here. Use the PPL wire from the stock starter to power the remote solenoid. 10 ga from battery to large remote solenoid post. The other large post to the OEM starter solenoid 10ga. NOTE 1: on the early GM starters they had 1 or 2 copper straps coming out of the motor assembly. 1 strap is a regular starter motor, 2 straps is a hi torque motor usually found on the big blocks or truck engine. NOTE 2: Use an OEM (Delco) solenoid not some cheap aftermarket replacement. All this can be done without crawling under the vehicle.
 
Well this is something I have heard before and you guys are probably right. Just bypass and do a fix that I know will work.

Fun side note this weekend went to get head gasket replaced. Pulled into place I was going to do it. Sat thee truck for a bit. Went to move it in the barn, absolutely no power to the truck, never head this issue. Fix that issue, then seems I blew a fuse. The original box is gone, the new one is a unknown lol. So before even starting the head gasket got this new issue.

Going to run a new wkre directly to the fuel pump. Last issue was one of the valve covers was pinned to the firewall. I saw that the last bolt has actually been shaved down to make it fit. Unfortunately it won't come out. So going to now cut the firewall a bit to give some space.

But I think I may take advice and look to fix the issue correctly and not a band-aid
 
I have a friend who had clearance issues. He took a 2x4 and beat the firewall back enough to clear. This was installing a BBC in '67 I just moved my BBC forward 1 1/2" IIRC,, same year truck. Holes were already in the frame.
 
When I trimmed my inner fender wells the heat soak Issue went away. Mine is SBC and headers though.
 
K5Devil said:
When I trimmed my inner fender wells the heat soak Issue went away. Mine is SBC and headers though.
Click to expand...
Makes a lot of sense because that should allow much better airflow. Good thinking!
 
So this is an LS swap into your 1980? I would think it's just the regular square body hot start issue - whereby a lot of remote solenoids get installed. The only time I've had poor cranking on a GMT800+ was a tired starter.

correct_solenoid.jpg
 
Given, what I know about LS engines you could write on the head of a pin with a magic marker, but when I installed my 454 I rebuilt my starter myself (used to do it as a side line income) and it still had heat soak problems till I mounted the remote solenoid. Just my experience.
 
I’ve seen this issue at work.

A heat shield will help and/or a wrap around the header tubes. You don’t need to wrap the entire header, just near the starter.
Remember you will need a space between the wrap/ shield or it won’t really work well.
 
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