'90 Ciera S - intermittent, possibly heat-related "shorting"

[HarpGuy]

I've got a '90 Ciera S that, to my astonishment, was sitting in my mother's garage when I opened it after going to her home following her death. What happened to the much nicer, new Mercury I'm still trying to figure out. But, in any case, after putting several hundred into it so I could use it to get my tools home to California (after fixing-up her house), I've been driving it because I'm by-god gonna' get my money back out of it!

At any rate, it has started doing something really odd, and only intermittently... and it's possibly heat-related (only I'm still trying to figure that out).

Basically, it runs fine most of the time. But sometimes, after I start it and pull out onto the street, the tachometer suddenly starts jumping all over the place; and all other dials go up or down (usually down); and the radio and other dash light dim; and all the dials and tach and speedo needles and gas guage and alternator guage and temp and oil pressure, etc., all kinda' bounce around like there's some kind of short (though it doesn't seem related to bumps in the road or anything like that)... especially the tach... it just goes wild. Sometimes it affects the engine, which starts to kinda' run unsmoothly, and sometimes it doesn't.

When it happens while I'm driving or sitting behind a car at a stop light, I notice the even the headlights (shining on the car in front of me) dim, then brighten, then dim, erratically... along with all the other stuff going nuts.

I took it to the mechanic and he said it happened while he had it (though it took a while) and while it was happening, he tested the alternator and said it was providing steady current... no voltage regulator problems, he thought. He said it sounded like something was clicking in the dash, but he said that could have been a symptom, not the cause... and he based that on the fact that the cruise control unit was clicking, too whenever it was happening. He said it was likely some nutty, intermittent electrical problem... probably in the dash... and he just didn't want to tackle it.

While he had the car, I had a thought: What if the vibration from the crappy tires (before I replaced them) had jiggled a fuse loose or something. So when I picked-up the car from the mechanic, before I started it up, I made sure all fuses were seated. And it started right up and didn't do it. But then again, it was the cool of the early evening, so who knows if it was that, or my reseating the fuses.

I'll say this much, though: I then drove it without a problem for weeks... relatively cool weeks, though, I've realized upon thinking back on them... although that may not really have anything to do with it.

At any rate, the other day, while sitting in traffic on a terribly hot day, it started doing it again. I drove straight home and parked the car and decided to check it after the cool of the evening set in.... but I forgot to do that.

So, today, I went out (very hot again) and tried again and, sure enough, needles bouncing all over, dash lights brightening/dimming, and this time, the engine not really wanting to stay running. I reseated the fuses to no avail.

So, now, as I write this, the precise symptom is: Will start (but with a tiny bit of difficulty... good cranking, though); but won't really stay running for more than a few seconds at a time; suns kinda' rough when it *is* running; radio and other dash lights flicker bright/dim (in no particular pattern) the entire time it's running; tachometer jumping all over the place; all other needles more or less dropping down, then up, along with the dash light brightening/dimming; and until I slid the cruise control switch to off, I could hear the cruise unit clicking along with all the other stuff. As it's doing all this, I can also hear relays clicking under the dash, but I think that's basically the same thing as the cruise control clicking: A symptom, not the problem.

If it behaves as it has in the past, I may very well be able to go out to the car this evening, after things have cooled off, and the darned thing will start right up and run smoothly without a symptom. I might even be able to drive it for days or weeks thereafter with nothing.

Has anyone ever seen anything like this?

Should I be looking for something behind the fuse box?

Could the voltage regulator be bad?

Is there some kind of master relay that could be causing this?

Thoughts, anyone?

I look forward to your replies.


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HarpGuy

[HarpGuy]

I originally posted the above in May 2009. It's now December 2009, and no one ever responded...

...which was/is VERY disappointing. I figured I'd find help in this place, for sure.

Maybe there just aren't that many people left out there who know anything about this particular car.

In any case, I thought, for the sake of those who might stumble onto this thread some day in the future, that I should post how it all came out.

You won't believe what it finally turned-out to be....



I had stopped driving the car and it just basically sat there. I could move it and all that, but not drive it far.

One day my wife's Honda Civic's battery was dead and so I gave it a jump off the Ciera. While connecting the jumper cables, I noticed that a little flat, braided wire running from the negative battery connector on the Ciera, over to a ground screw on the frame, was loose... broken, actually. I thought to myself, "Boy, wouldn't it be nice if it was something easy like that?" and then I just dismissed any such possibility in my mind and I finished giving the Civic the jump. Then I parked the Ciera again and forgot all about it.

But about a month later I actually dreamt about that being it, believe it or not. I don't put much stock in that sort of thing, mind you; so I'm not saying that some spirit or something came to me in a dream about it. I'm just saying that, for whatever reason, I dreamt about it being exactly as simple as that wire. Whoever knows why we dream the weird stuff we sometimes dream.

So, what the heck, the following Saturday I pulled the thing into the driveway up near the garage and I opened the hood and started experimenting. I could see that the wire was rusted all the way through, but its two halves where still touching. So I knew that when the car was going down the road, the bumps and whatnot were making those two ends make intermittent contact.

"Hmm," I thought to myself, "that would probably screw with the computer's little brains, I'll bet."

So I clamped them together. It made the car run a tiny bit smoother, but most of the symptoms continued. When I unclamped them while the car was running, though, the engine instantly died. So I knew it was an important connection, somehow. And that made me continue.

For grins, I decided to just repair the darned thing. It certainly didn't seem hard. Of course, I should have gone and gotten a new braided wire, but instead, mostly just because I was only experimenting, I sanded the ends down to clean copper, then fluxed them, twisted 'em together, then wrapped some ribbon solder around them, then hit 'em with the torch. Then I wrapped first the new joint, then the entire length of the wire in black electrician's tape.

Then I started-up the car and it still exhibited most of the symptoms, except that it did run just the teeniest, tiniest bit smoother.

Rubbing my chin, I suddenly remembered something a guy once told me about these older engines cars which started-out life without computers, but later had computers thrust upon them. He said that when one of them gets their little computer brains all squirrely, one has to disconnect power from them altogether -- both the hot and the ground from the batter -- then let 'em sit for maybe a half hour or so to ensure that bygod whatever electricity might have been in any capacitors and whatnot has dissipated; and then one should reconnect the ground to the battery first to discharge whatever might be left; then reconnect the positive to the battery very carefully so that one doesn't allow the positive to touch, then come away, then touch, then come away as one tries to thread-in the little screw that holds the positive cable to the positive terminal of the battery. By so doing, the computer is essentially reset.

"Hmm... well, I've got a half hour," I said to myself. So, I disconnected both the hot and ground from the battery, and then went back inside the house and answered a few emails for about 45 minutes.

When I came back out, I put the negative cable to the negative post of the battery first and secured it; then, being careful to make one good connection and not let it break while I connected the positive post, I threaded that in and tightened it.

Then I started the car.

Oh. My. God. It ran. Perfectly. All symptoms gone.

The only symptom was a new one: Rough running from my letting it sit too long and probably gumming-up the fuel system and plugs. But I knew what to do about THAT one. And so I did.

I'm still driving it. It's perfect. I can't believe it.

So, then, that little flat, braided wire (which ran from beneath the rubber sleeve of the negative/ground battery cable connector, across a small distance to a big screw with a hex head bolted into the metal of the frame right in front of the battery (to the left, as one sits in the driver's seat) of the radiator, behind the headlight)) obviously was pretty important. And it had rusted through and had caused the connection to be intermittent, and exacerbated by the bumps in the road. I'd have to go look it up to see what, precisely the wire actually accomplishes, but, obviously, it's needed.

One would think that the big black ground cable coming off the battery would run straight to a good, solid frame ground; and that that would be enough. But there's obviously something about this secondary connection that's important. Maybe it grounds the computer better or something. I don't know.

All I know is that the car now runs, I kid you not, almost as good as new. Of course, that's mostly because the guy who first owned it was a mechanic and took care of it. And the person he gave it to was my mom, who learned from my father (godresthissoul) how to keep a car up and maintained (though she had to pay mechanics to do it where my father did it himself). So that car's ugly and old, but it's like an almost new luxury car in terms of its ride and performance. The darned thing even smogged last month. I can't make myself sell it or give it away! [sigh]

I simply repaired that little ground wire; then got the fuel system and injectors and plugs all clean again (and fresh fuel in the tank, of course), and it's now good as new... er... well... you know... as good as new as a crappy old 1990 Oldsmobile can possibly be, all things considered.

Go figure, eh?



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HarpGuy

[maxwedge]

Thanks for the reply, I did not see this, I would have chimed in as I was an Olds SM back then. That ground is part of the sensor circuit grounding element so yes that would do it, especially after 20 years. I'd go over all of them especially the ones on the engine.

[HarpGuy]

Wow! An actual reply... finally... albeit after the problem is resolved. That's kinda' my luck in life, though, so no harm, no foul. [grin]

But, seriously, I am glad you replied. Thanks.

You mentioned that it's part of the sensor circuit grounding element; and that I should check ALL of them, especially those on the engine.

Are you saying that there are multiple of these kinds of little ground wires all around the engine compartment? You don't happen to know where all the places are that I should look, do you? The only repair manual I have for the car is one of those cheap, less-than-an-inch-thick ones with newsprint paper pages that one can purchase at the chain auto parts stores.

Finally, if you had a car like this one which has been maintained (remarkably well, to my surprise), with... I can't remember... I think maybe 150,000 miles on it or thereabouts... what other things would you keep an eye on or worry about?

Thanks, in advance, for your help!

(Wow. A real reply. Cool.) [grin]

[maxwedge]

There may be a ground on the engine near the t'stat housing or intake, don't rememeber but the are easy to spot, blk 16 gage ring type connectors. Rust and/or corrosion are the enemies of a 20 year old car, especially around the subframe supports near the firewall. But in Napa I guess not.

[HarpGuy]

Originally Posted by maxwedge

There may be a ground on the engine near the t'stat housing or intake, don't rememeber but the are easy to spot, blk 16 gage ring type connectors. Rust and/or corrosion are the enemies of a 20 year old car, especially around the subframe supports near the firewall. But in Napa I guess not.

Well... it's true that it's very dry in this part of California. In fact, when I moved here, forty-something years of sinus problems which I experienced in the midwest (and a short stint in Florida) went away. I can BREATH again! [grin]

So, then, the car, now that it's out here, will likely not get any rustier (or at least not much more so) than it already is. However, it spent most of its life in the Chicago area... rusty-car capital (due to road salt) of the world... er... well... now that I think about it, maybe not. Florida's worse... but for different reasons.

When I lived in Tampa, though only for about three years, a boxful of tools in my trunk which NEVER got rusty for years in Chicago finally did get rusty in Florida... after only a couple or three months, to boot! It's because of the salt air rolling-in off the gulf, I learned. People would joke, when I talked about it, that in Florida, if one's car is, for example, parked in a driveway right outside of one's bedroom window; and if one has said bedroom window open at night, and then lies very still and holds one's breath, one can actually hear one's car rusting as it sits in the driveway all night long.

Though being able to hear one's car rusting is the joke part, that it rusts and how fast it happens isn't. After three years in Florida, the car I drove down there from the midwest had, by midwestern standards, ten more years of rust on/in it. I ended-up selling the darned thing and leaving it in Florida, and then just flying out to California and buying a car out here... which I still have. But now I also have my mom's old '90 Ciera... which I'm bygod gonna' get my money out of before I finally retire! [grin]


I'll check for more ground wires around the intake manifold, and the thermostat (and anywhere else I happen to spot 'em). Thanks!


If anyone else familiar with this car (which I'm guessing is pretty much the same as similar-body-style other-make GM cars from that era) has suggestions, please let me know.



______________________
HarpGuy

[msattler]

LOL........My '92 with the Iron Duke 2.5l has about 92,000 on the odometer.

It was owned by a little old lady up in the north woods, and it sat for years in a moist driveway.

I got it at auction with about 64,000 miles on it, and the rust will kill it long before the motor dies.

Replaced a few brake lines and the whole gas tank assembly so far............
One of these days, the unibody will go scrunch........and break right in two.

And the 2.5 will still be good to go....where, I don't know....LOL.