Diagnose alternator on '95 Suburban?

AaronW

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All:

So recently, I noticed that my voltage was dropping, and then kicking back up again. Then this evening, my voltage dropped clear down to 9 volts, and I barely made it into the grocery store parking lot. I've never seen an alternator gradually go bad like that, but I can't think of anything else it might be.

I think I'm in some kind of bermuda triangle. I'm not making this up: Just as I got into the grocery store parking lot this evening, with what I assume is probably a bad alternator, I started shooting coolant everywhere. I'd been smelling antifreeze the last couple times I shut it off and got out, but hadn't seen any drops. Recently had the whole system flushed out real good. Further, I'd recently been hearing a weird noise that sounded like it was coming from the AC pump, but maybe it was the water pump, given what just happened.

Ok, so I can't think of any possible connection between losing an alternator, and some kind of major coolant leak, so maybe I should just go buy a powerball ticket. (I've been hit by lightning already).

You guys think I should just go get another alternator, and start there?

Aaron
 

bucket

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Does it still start on it's own? If it was actually down to 9 volts, it probably wouldn't have restarted without a jump. Do you have a load tester or a multimeter? If you don't have a multimeter and the truck still starts, start it up and turn everything on. Headlights, blower on high, rear defogger, wipers on high, etc. If it's showing 9 volts on the gauge then and everything is working normally, it's a safe bet that the gauge is wrong.
 

AaronW

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So I got my issues fixed: New alternator, and replaced the thermostat, and it looks like I'm good to go. So basically, I just had a pretty major coincidence happen, I think.

While I'm at it: I think I've got a bad EGR valve on the same rig. Fired I'd replace it, and while I was looking at how to clean them up, too, I ran across a guy arguing that deleting tem altogether increases your fuel economy. Any opinions here, on if/how much that' true? (edit: ok, So I didn't realize that I'm apparently putting my foot in it, by asking this)

Aaron
 
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fast 99

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The EGR injects exhaust into the intake stream to cool the combustion chamber temperature lowering NOX emissions. If removed there is a chance the motor will ping. If emissions tests are required in your area the vehicle may fail. It will also turn on the check engine light. Some people have removed them without drivability issues.
 

AaronW

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Emissions tests aren't an issue where I live...and my catalytic converter is going away too... but this squares with what I'm seeing around, as far as the criticisms go. Anyone got a real-world example of fuel mileage improvement?

Aaron
 

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So I got my issues fixed: New alternator, and replaced the thermostat, and it looks like I'm good to go. So basically, I just had a pretty major coincidence happen, I think.

While I'm at it: I think I've got a bad EGR valve on the same rig. Fired I'd replace it, and while I was looking at how to clean them up, too, I ran across a guy arguing that deleting tem altogether increases your fuel economy. Any opinions here, on if/how much that' true? (edit: ok, So I didn't realize that I'm apparently putting my foot in it, by asking this)

Aaron
No deleting it does not increase fuel economy. EGR works by partially filling the cylinders with exhaust gas(inert gas) at low power demands. It doesn't make things rich or lean. It does however occupy space in the cylinders so you can't fill the cylinders as full with fresh fuel and air. Results you burn less fuel because you can't get as much in. Your combustion chamber Temps lower because your not burning as much air and fuel. EGR should drop clear out of the equation at high power demands or when the engine is cold. You can think of it as kind of a crude variable displacement device.
 
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AaronW

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Thanks for the reply. I kinda figured that this was one of those "if it worked that well, everyone would be doing it" things, but I'm not technically versed enough to know all the ins and outs of why.

Aaron
 

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