need help. on road trip overheating

[alc5m]

Hey guys I've got an issue here. My 03 5.3 keeps killing itself while driving. The first few times this trip engine bay had been normal operating temp. By feel. This last time I had the air on had yo wait half hour to cool down

This has happened twice beforein the last month. Idled for almost 45 minutes in a parking garage leaving an event hit the gas to go and killed it. Alternator was burning to the touch

Replaced alt and about two weeks later (earlier this week) I pulled a trailer ubhooked it went to a drive thru and when I left there it killed itself.

First two times were after idle these times on the trip are freeway

Nothing wrong on the gauges. No dummy lights no check engine. Temp gauge stays at 190/210 area.

Anyone have any ideas. My first thought is water pump or thermostat but I can't be sure. Can't check the weep hole. Lowered a bit plus z71 skid plate means no go on that.

Any help is appreciated thanks guys

 

[yates ™]

What exactly is over heating? You mentioned the alternator was hot and you replaced it and now worried about water pump and thermostat but the temp is not showing hot. I think it sounds like you have an electrical problem and that you are not over heating but then again I am having trouble following what is being said.

 

[alc5m]

Sorry. Frustrated typing lol

I had the thought if an electrical problem the first time it happened which is why I had replaced the alt the first time it happened.

The engine bay, when the truck dies and doesn't start up again right away, is extremely hot. The alt is prob super hot to the touch just because of heat transfer to the aluminum housing.g as well as the brushes and coils. The other thought I had was the alt gets too hot for the charging to function properly but then the question becomes why is it overheating like that?

Only other thing electrical I replaced recently was upgrading my battery to a yellow top but I had that In for 4 months before first time it overheated

 

[yates ™]

Lets rule out fluid, what does your temp gauge read, is there anywhere that you can see that antifreeze has sprayed out?

Are you sure you are not grounding out anywhere in the wiring?

 

[alc5m]

Gauges read normal across the board and I don't see coolant anywhere in the bay besides in the resivoire.

Not sure about grounding out cause I never really changed anything to where something could ground out. Any ideas on what wires to look for. Also any ideas as to why the engine bay got way hotter with the AC running than without?

 

[Rivieraracing]

Try cleaning your throttle body, sounds kinda like the problem I get when mine gets very dirty!

 

[alc5m]

What would a bad thermostat give for issues?

 

[zieglerj-pdm-specialist]

But IF??

If the temperature is not showing that its overheating you can rule that out unless the temp gauge is defective. Does the engine warm up from zero to the point where the temp gauge climbs to the natural running temp, the gauge is not stuck on 210 or whatever it may be. I don't see how the alternator would get so hot that you cant touch it?? unless some wires are loose generating more heat than it should. You need a good solid connection on the alternator or it will generate extra heat. Is for some reason your brake or emergency break me be faulty and causing the engine to over work. How is your gas mileage and your RPM while running at normal speed of 65? If it was your water pump it would be leaking throwing your serpentine belt if its locked up or it would make gravely noise from bad bearings. Pull the air filter out and see if your engine runs better just by sitting idle. The vehicle maybe trying hard to suck the air in and its starving for air causing overheat. That's my 2 cents does any one agree? Or am I way off base again.

---------- Post added at 06:46 PM ---------- Previous post was at 06:44 PM ----------

What would a bad thermostat give for issues?

A Bad thermostat would not give your vehicle any coolant there for causing your engine to over heat in a couple miles of driving it. Your temperature gauge on your dash will be hotter than 225 it would get near the red.

 

[alc5m]

What about it vapor locking the engine though?

There was an Allstate service guy who stopped and that was one of his thoughts.

And as far as I know I tightened everything in the alternator as tight as it could go

 

[zieglerj-pdm-specialist]

What year is you vehicle

Gauges read normal across the board and I don't see coolant anywhere in the bay besides in the resivoire.

Not sure about grounding out cause I never really changed anything to where something could ground out. Any ideas on what wires to look for. Also any ideas as to why the engine bay got way hotter with the AC running than without?

By using the A/c it engages the A/C compressor causing the engine to work a little harder but nothing that was cause heat like your explaining unless the bearings on the clutch or the bearings on the compressor are going bad in which you would hear a grumbling noise from a bad roller element. Start it up open the hood and listen for anything that is making more noise than any other piece under the hood. I just wish I had all the details of this problem and we could figure this out if we knew everything that happens, when it happens, how it happens, are you towing anything. check the brakes. Im here to help but I need all the details.

 

[alc5m]

Man I've told you pretty much everything I know. No extra load just driving. The first time it happened was in a parking structure where I sat for 45 minutes idling the second time I had pulled a trailer about half hour before O went to get food. When I got my food after sitting in a drive thru I hit the gas and it sputtered and died.

The times on this trip here love just been cruising down the freeway. No weird rpms no strange noises no dummy lights nothing. Just lose all power engine shuts off I even lose powersteering.

 

[yates ™]

It's an electrical problem of some sort.

 

[zieglerj-pdm-specialist]

Crap

It's an electrical problem of some sort.

Electrical fault that overheats the whole engine bay that doesn't raise the Temperature gauge and causes the engine to shutdown? This one is a tough one. Do you have any check engine lights Is the Radiator gummed up causing not good flow going through the engine but that would cause the temp gauge to jump. Is the electric fans working in the front that blows air through the radiator. I hope this helps. Take Care

 

[Toms01PSD]

I'm no expert, and I don't currently own a Tahoe, but try popping off the exhaust at the catalytic converter and see if its clogged or glowing cherry red. I worked on one once that would not throw a code but it would die while driving randomly. It would also go into limp mode, though. Could explain you losing power also. Worth a try...

 

[yates ™]

The only thing hot is the alternator. Explain to me why the truck would shut off if it over heated?

 

[livingez_123]

Idling in a parking garage with the ac on for 45min. no air flow, the alt is trying to keep up with the fans on. I can see where this would be very ******* your alt. when the truck idles there is minimal cooling, charging, something is going to give. It just depends on what part is weak.

 

[alc5m]

I'll check the cats. My dad and uncle are thinking maybe thermostat too. And I misspoke earlier the engine bay does get hot but nothing on the gauges says its hotter than normal although while sitting outside of Chicago for almost 1.5 hrs the coolant lines were considerably cooler than the alternator was

That could just be heat transfer difference between metal and rubber but who knows. On the times when it wouldn't start up right away again the coolant in the reservoir was higher than when it would start up again right away meaning the engine did get hotter at that point.

I'll dig into it this week but the alternator I put in there was completely brand new not a remain and is 145 amp alt. And I only turned the air on once this wknd. Every other time was just windows open driving. Between the Indiana border and south Chicago it died pretty much every ten to fifteen minutes but that was in no move traffic. Although when I could open it up it still died right away


Also to whoever asked about efans, they didn't out efans in until 05. Mines mechanical

And when the Illinois dot towed my truck off the freeway when I put my foot on the brake to put it back to park it felt like abs was on I shut the truck off and when I turned it on again my brakes were real tough and my abs light was on

 

[Toms01PSD]

Look at it yet?

 

[zieglerj-pdm-specialist]

I'll check the cats. My dad and uncle are thinking maybe thermostat too. And I misspoke earlier the engine bay does get hot but nothing on the gauges says its hotter than normal although while sitting outside of Chicago for almost 1.5 hrs the coolant lines were considerably cooler than the alternator was

That could just be heat transfer difference between metal and rubber but who knows. On the times when it wouldn't start up right away again the coolant in the reservoir was higher than when it would start up again right away meaning the engine did get hotter at that point.

I'll dig into it this week but the alternator I put in there was completely brand new not a remain and is 145 amp alt. And I only turned the air on once this wknd. Every other time was just windows open driving. Between the Indiana border and south Chicago it died pretty much every ten to fifteen minutes but that was in no move traffic. Although when I could open it up it still died right away


Also to whoever asked about efans, they didn't out efans in until 05. Mines mechanical

And when the Illinois dot towed my truck off the freeway when I put my foot on the brake to put it back to park it felt like abs was on I shut the truck off and when I turned it on again my brakes were real tough and my abs light was on

Check the brakes after it shuts down jump out and put your hand on the rim if the rim is hotter than $hit your caliper is locked and causing your engine to work very very hard amping the temp of the engine. Long shot because you should feel that drag. This is from the left field fence but when did you change your transmission fluid and your oil that could be gumming up your mechanics? Again this is from the cheap seats....

---------- Post added at 07:10 PM ---------- Previous post was at 07:07 PM ----------

The only thing hot is the alternator. Explain to me why the truck would shut off if it over heated?

Check all of your connections on your alternator to make sure that they are secure. Loose connections cause heat. I am an Infrared specialist and if I find a connection that is hotter than others its due to loose connections not tightened to spec. So check all the connection even the ground.

 

[Vette66]

I know it's not a Chevy/GMC but my sons car did the same thing, ford Taurus, it ended up being battery cables. The positive side was corroded at the crimp. Causing the alt to work harder. Then all the sudden dead. Wiggled connections and it would start up and be fine for a short time.