Main IndexAuto Repair Home Search Posts SEARCH
Who's Online WHO'S
Log in LOG

Search Auto Parts

Battery causing transmission issues?

  Email This Post


Jun 14, 2019, 9:58 PM

Post #1 of 6 (666 views)
Battery causing transmission issues? Sign In

(1996 Buick LeSabre Custom, 3800 Series II, 3.8L V6)

I've never had transmission trouble before.  I had a new battery installed today, and I didn't realize the guy at O'Reilly's had not tightened the battery cables very tightly at all.

Minutes after the battery was installed, I was slowly driving in a parking lot, and gently accelerated to make my way down the aisle.  Suddenly, the car stopped, but the engine was still running and slightly revving as I stepped on the gas.  It didn't stall.  It was like someone had shifted my car into neutral.

I thought perhaps I hadn't put the car fully in drive, so I put it in park and then put it in drive again.  A few blocks later, the same thing happened, this time on a busy street.

A backyard mechanic I know came to look at my car, saw that the transmission fluid looked good, and noticed that the battery cables were on very loosely.  He tightened them, and I didn't have problems for the rest of the evening, even when I drove on the highway to go home.

I did a little research, and found articles saying that battery corrosion can cause all sorts of weird problems with the transmission.

The backyard mechanic who looked at my car didn't think the battery would have any effect on the transmission, but apparently it can happen.  And he admits that he doesn't know much about "modern" transmissions, anyway...he knows more about older carburetor engines.

My cables don't have corrosion, but they *were* practically falling off the battery.  I've changed batteries in my day, and even I have never left them that loose.  I'm amazed the car even started.

Does anybody here know if loose battery cables could cause this issue with a LeSabre as old as mine?

(This post was edited by wildirish on Jun 15, 2019, 2:07 AM)

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 14, 2019, 11:20 PM

Post #2 of 6 (655 views)
Re: Battery causing transmission issues? Sign In

Battery wasn't even tightened in no telling what problems could happen. It seems like it's fine now just make sure it's fully mounted and in there properly, any other pre-sets you may have are reset and don't let some twit do that again!
Better for another time just get the battery and have a shop install it and take back the old one it can be changed and not disturb the whole show if just periodic to get a new one is a good idea,



Jun 15, 2019, 2:15 AM

Post #3 of 6 (643 views)
Re: Battery causing transmission issues? Sign In

The battery was under warranty, so they had to do the exchange at O'Reilly's. But next time, I'm going to change the battery myself. It's ironic to think that I let them change it because I'd had a really awful day at work, and I was concerned but I would screw up the job because I was tired. Feeling that car shift into neutral in the middle of a busy road certainly got the adrenaline pumping....

I'm just relieved to learn that I don't have a very serious issue with my transmission.

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 15, 2019, 3:40 AM

Post #4 of 6 (640 views)
Re: Battery causing transmission issues? Sign In

Know this about touching a battery:
This car isn't ancient if by electronic controls that have a memory - it does, almost all do.
With that get or learn how to save the memory for that or specific cars if so much as disconnecting a battery for any reason. A good one is clean terminals and lube or corrosion proof there if that alone.
If out for a while you need back up power to the vehicle's things (computer and more stuff) controls. Can be done with costly stuff or some real know how to keep the 12V there while battery is out like take that one back to swap out for warranty or longer sometimes.
These places and hurried shops even just wont do that! Now the car in this case lost radio stations, the clock reset, any seat position settings if equipped, the memory of any fault codes or ones pending are lost. This and others also remember how to hold proper idle speed over time of use will default to slow re-learn mode. It would also say "not ready" for many places for routine inspection stickers would have to go back later!
Transmission works in cooperation with how engine runs can default (anything possible with wild intermittent power loss from a battery) could either confuse it or cause real damage! This case probably not.
There's more! New battery isn't necessarily fully charged? Yes - get a "maintainer/charger" with auto shut off and charge your own new one. Why? If at 1/2 charge your alternator works like all nuts to charge it gets way too hot for many and the real troubles can begin. That speed charge can ruin the battery so play ping-pong killing each other, both need be right at the same time and pretty much all the time!
There's a mix of expectations from parts places and the tech skills of how to do a thing! Parts sales is about selling a product can be the finest place doesn't mean they are experienced techs in fact most are not. Sure today there may be an info sheet with parts seen to them maybe to you. One is they see ideas on what else they can sell you if buying an item what might go with it! There's a snag there of what is in your best interest.
Last for now but most important: DO NOT RUN AN ENGINE WITH A BATTERY DISCONNECTED!! That was a trick back did tell if a "generator" in a car worked! Cars don't use generators and haven't for some 50+ years so dump that but if terminal is loose it's just like disconnecting it. The newer the worse it will drain any power from anything with a memory and perhaps ruin that. Now older that much harder to fix that problem and wires, connections don't like cooperating bust makes a whole project just to run again.
One more last thing :-) == About always when disconnecting a battery do the NEGATIVE cable first and back on LAST! Why? So any tool you touch to POSITIVE cable doesn't touch nearby metal and short out! That's annoying to dangerous if that happens so pay attention.

Sorry for the novel this stuff isn't new to most electric start motor vehicles since the 1960s and yes I was there when they were new!



Jun 15, 2019, 9:21 AM

Post #5 of 6 (625 views)
Re: Battery causing transmission issues? Sign In

I knew I was in trouble when I saw this kid disconnect the positive terminal from the battery first. He went in to ask his supervisor how to finish the job, but the supervisor didn't even spend 5 minutes with him. I did remember that you should never run a car with either terminal disconnected; I had the keys on me, so at least this guy wasn't able to do that!

You just reminded me that all the engine codes my car has recently thrown have now been cleared. This is frustrating, because I've been having intermittent issues with the EGR valve. But that's a story for another post.

All this other information is new to me. I will have to look into buying a charger to make sure this battery is fully charged.

I appreciate your help very much. I hope the car will make it back up to the city, because I want to have someone make sure these cables are connected properly.

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 15, 2019, 9:59 AM

Post #6 of 6 (616 views)
Re: Battery causing transmission issues? Sign In

So far so good sorry codes gone I just knew that. It's also lost fine tuning how engine runs within perimeters that are fine for the age and miles even all things normal. It may stall for example both steer and turn at the same time with engine just coasting. It will quit that in so many cycles of starts to fully warmed up and cooled off again.

EGR was already there just know doesn't mean the part is the issue just that circuit or system is able to set a code. Could just be silly or go away now it's not going to run it's best isn't helping thanks to that twit - follow me? They don't mean it (most) just don't know.
Charger/maintainer. Own a dozen had a lot of stuff. Best was by Black and Decker both shock and waterproof! Not sure I trust it that much. That one can do 2 AMPs and will to fully charge to set voltage of 6 or 12V batteries it know which some how? It turn off overcharging is no good thing up to ruin a good battery. Anyway found it at Home Depot I'd check whatever has the best price but liked that the best. I think in store was about $30 not certain.

You seem to have the basics and common sense and did just adding to it for this or your next vehicle/thing whatever the world comes up with the stinks worse than the older stuff is right up my alley except for terminally rusted certain things (things in general) can last generations.

Chat on that. My fav bench grinder is probably 1930s! Why the guess. The guy who gave it to me has passed away was in in 80s I think got it from his dad a machinist. It has oil cups for the bearings is dating it smooth as glass doesn't shake everything off the workbench the new one does! Nice!

One of those days - have a good one,


  Email This Post

Feed Button

Search for (options) Privacy Sitemap