1990 Buick Lesabre Electrical Issues
 

Hey everyone! My sister has a 1990 Buick Lesabre with about 140k on it. The car has been in her ownership for multiple years and has never given her much trouble until recently. About a two weeks ago the car was having trouble starting so she wasn't able to drive it for the day. Later on in the day my father went out and gave it a try and it fired right up. We thought that it might have just been a little hiccup, nothing huge.

Fast forward a couple days and my dad noticed a ticking noise coming from the car while it was off (no keys in ignition). If you start the car and then shut if off you can hear a ticking sound every few seconds. The odd thing about this is that it doesn't happen every time, maybe 8/10 times. Now this "ticking" sound is more of a rotating sound (hard to explain). Basically it sounds like something is spinning or spooling and it just keeps repeating. To remedy this issue we disconnect the negative terminal when she isn't using the car. I'm hoping someone can provide some insight on this issue? We can't see any moving parts or anything that looks out of place when looking at the engine bay.

The problems don't stop here though! Just the other day she was driving around town and her car shut off in the middle of the road!

The only thing I can think of is that there is a ground problem or something severely wrong with the electrical system in the car? Do these cars have distributors?

*The only work done to the car in the past three years was the alternator ( I believe it was a new non-OEM part. I'll try to get a video up in the next few days to help further understand the sound.

*EDIT- There are no check engine lights.

Thanks a lot!

-JTMx29

Would you know if this car has anything like Automatic Level control That maintains the vehicle in a level position if some additional weight were added to it in the trunk for example?

Time for a new ECM? ECM's were troublesome during this time period. Difficult or impossible to troubleshoot as well. Replace....problem fixed.....good deal. Replace....problem still there......bummer.

I've never heard of that before so I'm not sure?

Do you feel that this would be a likely culprit?

Could you provide some addl info like where the noise appears the loudest. If you open the hood can you then let us know where , driver's side, passenger side , engine compartment, inside the car, that you hear the noise the strongest.
I'm sure you are aware every time you disconnect the battery the computer has to relearn everything relating to your driving habits.
Let's see if we can help pin it down before you go spending money on something that may not solve the problem.

If it's not too much trouble , how did you determine the ECM was the problem before checking everything else ?

There were some problems with the intake plenum leaking coolant into the engine oil.
Most folks I know were very happy with their Buicks. Of course you can't compare the ride with any other car. They were in a class of their own there. Continue searching and post your results , would like to know if there were any big problems.

If it has a check engine light issue, you can usually grab the codes off of it and narrow your issues down.

There were, as I mentioned, many issues with this ECM though. Most of the time no trouble codes, just crazy crap going on. Lots of sensors going bizzerk under the hood with the car off, key on. Driving highway speed and the car dies for no reason, no warning, etc.

I had similar issues as the first poster. Went to the junk yard, picked up a ECM for $35, changed proms from mine to the new used one and bingo, no more problems.

PCMs do crap out for no particular reason sometimes, but most of the time there was a problem somewhere else that wound up taking the PCM out with it. The early vehicles were not that complicated as compared to today's and I still drive a 90 Century with 136,000+ miles on the clock and it is one of the better Buicks I have owned. As always , it has that typical Buick ride quality. Very dependable too. I have had to replace the crank sensor, ECM because the cooling fan was always running, and routine stuff like plugs ,wires, tires, battery, brakes ,exhaust system etc. There is no such thing as a free ride and you have to expect to replace things that wear out.