Sad Che++y Diesel

[Matt42]

I am stuck with using a 1998 Chevvy 6. 5 diesel at work. To date, it has had the engine oil cooler lines let loose on US 93 near Nothing, AZ, plus numerous untraceable oil leaks. Today, we had to have it towed into the dealer because both batteries were dead. It wouldn't even jump start. (The tow operator recognized the truck from previous times. ) The batteries are 18 month old Optimas, which tend to do much better than that. Has anyone had any experience with spontaneous Chevvy Short Circuits in the alternator, or someplace in the harness? Bats? Gremlins? Quonlins? If no experience, how about stories or urban legends? I need to take it on the road in 36 hours. If it's not ready, I will have to use my own 1996 Ram DC. I can access this email address while on the road ----> mshumaker42@hotmail.com

 

[HC]

This may be too obvious, but on my Chevy Diesel (long gone), and later a Chevy gasser, the issue got to be as much the quality of the connections as the batteries. (I HATE side post batteries!) If you didn't replace cable ends when you got the Optimas, I'd try at least getting new bolts (the ones that screw into the side post batteries to hold the cable on), and maybe even new cable ends installed. I'm guessing you've got some corrosion products still messing up the quality of your connections to the batteries. This in turn could have led to overcharging, undercharging, or some other electrical problem that might have caused early death of the Optimas. If you had a major short, or a dead diode in the alternator, that should have shown up in a basic test done at the shop when you got the new batteries. So something slightly less obvious, like connections, might be the issue.



GOOD LUCK!

 

[Matt42]

An interesting observation, thanks. Both batteries showed zero volts with a voltmeter. That was checked at the posts and the side terminals, as the Optimas have both. Connections looked OK, seemed tight, but I didn't fiddle with them. The Optimas on my own 1996 have survived three years of ghastly use in 118F-plus city traffic, without a peep. But only 112 today.



As engines and engine management thingies get more complex, I find that some of us (me) tend to overlook the obvious things. Battery cable corrosion. Vacuum leaks (on gassers). Bad grounds. Low tires. Low bidders.



I had heard or read or dreamed or hallucinated that some few batches of Delco alternators had internal problems that spontaneously caused a short circuit, doing in the batteries. It's at Lou Grubb Chevy in Phoenix as I peck, and they tend to do pretty well at diagnosis and repair. They have a sizeable truck business, and have been around since wood spoke wheels.

 

[Doc Tinker]

I've been known to cut off the insulation around the ends on those side post cables. Then I replace the original bolts with grade 8 bolts and a nut that tightens down on the teminals. You have to be carefull that of the bolt length (hence the nut) or you'll pop through the battery terminals, so don't let the bolts bottom out. After that's done, you have a good place to clamp your jumper cables to, incase the batteries die again.



The alternators on the Chevys seem to keep getting smaller in diameter every year. I've always been told bigger is better so evidently Chevy doesn't measure up.



Make sure the belt and tensioner are in good condition. The belt might be slipping.



I don't know how any of this will help you, but I felt like saying it anyway.



Doc

 

[danandamy]

I've always said there's a special place in eternity for the guy who invented side mount batteries and it ain't a nice place Yes, they do keep makeing them smaller and what's worse, they're forcing them to put out higher and higher amps. Used to be if you had a 100amp delco alternator, the thing was the size of a house but you couldn't tear it up. They changed designs again around '98, I believe. It's obviously a knock off of the Nippon Denso alternators our Rams use only, like everything else Chevy does, it's a a CHEAP knock off. These new designs are "smokers". One last thing, on your newer GM alternator, remember that they have to get 12volts to charge. If the alternator doesn't get a good solid 12v hit from the battery, it won't charge. None of that yanking off the battery cable to see if it keeps running bit, unless you want to buy a new alternator.

 

[rickhans]

Your problem does not sound uncommon for the Chevy diesel. I have a 6. 2 '83 Suburban and have had this happen several times. It is very difficult to jump. It usually requires two separate vehicles, one jumped to each battery. I keep a big Sears battery charger around and carried it quite a bit because it would usually start it when jumping would not.



One of the causes I found is the high amperage requirement of the starter on the Chevy diesel. I 17 years, 250,000 miles, (150,000 on first engine, 100,000 on second engine - a 1985 engine - after it was stolen) I went through around 6 or 7 starters. When the glow plugs come on while cranking the voltage drops and overheats the starter. And as was said earlier, the side mounts can make it worse. I changed to top mounts early on, but the wires heat up as well and cause voltage drop.

 

[JohnE]

If the batteries go dead the first place I check is the starter or more specifically the solenoid. The control circuit can fail and provide a nice dead short to drain batteries which also screws up the jump start ability. My alternator failures have always been brushes, diodes, or controller which results in lack of charging, never a short circuit.



John