'89 LeSabre Instrument Cluster Issues

[Superslug360]

Hey all, I've been hard at work getting my $250 LeSabre fixed up and road-worthy. It's a great car!
I'm having issues with the instrument cluster and I was wondering if anyone had any experience with these. Essentially, the speedometer works, temp gauge works, gas gauge works, and all the lights work. However, the tachometer and oil pressure gauge don't work. When I bought the car, the oil pressure gauge worked, and now it instantly pegs out to the max when the ignition is switched on without the engine running. The tach never worked, it rests on the redline peg and doesn't move. When the car is revved near redline it moves backwards slightly but that's it. I have already pulled the cluster once and didn't see anything obvious when it was out.
Any help would be appreciated! The car is treating me well otherwise, and I've done a ton of work to it.

 

[BuickGirlFromMars]

Hey all, I've been hard at work getting my $250 LeSabre fixed up and road-worthy. It's a great car!
I'm having issues with the instrument cluster and I was wondering if anyone had any experience with these. Essentially, the speedometer works, temp gauge works, gas gauge works, and all the lights work. However, the tachometer and oil pressure gauge don't work. When I bought the car, the oil pressure gauge worked, and now it instantly pegs out to the max when the ignition is switched on without the engine running. The tach never worked, it rests on the redline peg and doesn't move. When the car is revved near redline it moves backwards slightly but that's it. I have already pulled the cluster once and didn't see anything obvious when it was out.
Any help would be appreciated! The car is treating me well otherwise, and I've done a ton of work to it.

so its pegged when off? It may be physically in the wrong position inside if its doing that all the time

The oil pressure sensor would be by the oil filter adapter , above it somewhere

 

[Superslug360]

When the ignition is off, the gauge moves back to 0. I tried unplugging the sensor and it does the same thing. I'm guessing it's something to do with the actual dash, but I'm not sure.

 

[BuickGirlFromMars]

When the ignition is off, the gauge moves back to 0. I tried unplugging the sensor and it does the same thing. I'm guessing it's something to do with the actual dash, but I'm not sure.

the tachometer is moved by the Ignition Module under your coil (single piece of plastic with all 6 plug wires on it) If you are talking about the tach. I dont know what your reply is to because you didnt reply to both of the things I said.

do you have a t type cluster or a normal one
it would be nice to see it

 

[Superslug360]

Sorry, I misunderstood what you said. Yes, the tach is always pegged at max, even when it's off. I'll attach a photo when I can, my dash looks just like the one you attached. If there's corrosion under the ignition module, could that cause an erratic tach? It looks pretty rough under there. Thanks!

 

[BuickGirlFromMars]

Sorry, I misunderstood what you said. Yes, the tach is always pegged at max, even when it's off. I'll attach a photo when I can, my dash looks just like the one you attached. If there's corrosion under the ignition module, could that cause an erratic tach? It looks pretty rough under there. Thanks!

Do you have an T type?no the corrosion isn’t likely to be the cause if your tach is maxed when off. But it is still helpful to pull it off and clean the module to the engine bracket. Then use thermal paste to increase the heat transfer and prevent corrosion. If you have a single coil with 6 posts, if it ever goes bad I recommend upgrading to the 3 coil style which requires a bit of eBay hunting for a bracket from early series 1 engine to do so

 

[Superslug360]

Do you have an T type?no the corrosion isn’t likely to be the cause if your tach is maxed when off. But it is still helpful to pull it off and clean the module to the engine bracket. Then use thermal paste to increase the heat transfer and prevent corrosion. If you have a single coil with 6 posts, if it ever goes bad I recommend upgrading to the 3 coil style which requires a bit of eBay hunting for a bracket from early series 1 engine to do so

It's not a T-type, it's a Limited Sedan. I'll clean up the corrosion and see if that helps. Yesterday the harmonic balancer split in half while I was driving, so the instrument cluster is going to have to wait for a bit! Do these dashes have stepper motors? I wonder if it experienced an internal failure, or maybe a chafed wire.

 

[BuickGirlFromMars]

It's not a T-type, it's a Limited Sedan. I'll clean up the corrosion and see if that helps. Yesterday the harmonic balancer split in half while I was driving, so the instrument cluster is going to have to wait for a bit! Do these dashes have stepper motors? I wonder if it experienced an internal failure, or maybe a chafed wire.

No, not stepper motor, its going to be coil-type tachometer, so no sweeping when key on. Your needle could just easily be stuck or there is a bad component, it should be easily fixed by sending off if its failed

The balancer is VERY important. your crank shaft sensor is hard to get to .. and requires an alignment tool.,. if you want to do it proactively, trace the sensor location with a marker somehow to reinstall a new one EXACTLY in the same spot, so you dont ruin the sensor and balancer. or just put a new one on. The balancer bolt is hard to get off, and you need a puller.

The engine should be kept from rotating with rope in the cylinder you can best access to get the proper torque on the engine balancer bolt

 

[Superslug360]

Great, thank you. Who does repairs for these dashboards? I ordered the parts to fix the balancer.

 

[Superslug360]

Well, I replaced the harmonic balancer today and the Buick is driving once again. I think I found something that could be causing my intermittent stalling/stumbling/hard starting issue. The underside of the ignition module has a lot of aluminum corrosion, to the point where it's flaky. When you say a 3-coil ignition module, would a Series II ignition module work, or should it be from a Series I?
I have attached pictures of my dash, one pic with ignition off, one with ignition on:

https://imgur.com/a/Em00wP6

(Sometimes the oil sensor sits at 0 when off, sometimes it sits at 40. Not sure why)
Thanks for your help, I appreciate it!

 

[BuickGirlFromMars]

Well, I replaced the harmonic balancer today and the Buick is driving once again. I think I found something that could be causing my intermittent stalling/stumbling/hard starting issue. The underside of the ignition module has a lot of aluminum corrosion, to the point where it's flaky. When you say a 3-coil ignition module, would a Series II ignition module work, or should it be from a Series I?
I have attached pictures of my dash, one pic with ignition off, one with ignition on:

https://imgur.com/a/Em00wP6

(Sometimes the oil sensor sits at 0 when off, sometimes it sits at 40. Not sure why)
Thanks for your help, I appreciate it!

the coils , to my knowledge, can be up to possibly the series iii engines, and supercharged coils are better than NA cars. id use a junkyard for cost and quality.

The module has to be from a series 1 tuned port, and im pretty sure the bracket has to be as well.

You will be able to get this base plate from any 93-95 Vin L " Tuned Port Injection " 3800. But you can also find this same baseplate on many 92-93 Grand Ams with the 3300 V6, Buick Century 89-93 3300 V6 (wagon included), Olds cutlass Ciera 89-93 with the3300 V6 (wagon included), Buick Skylark 89-93 with the 3300V6, and Olds Achieva 92-93 with the 3300 V6. The base plate with the two mounting brackets on the right hand side will not work.

 

[Superslug360]

Awesome, thank you. I have a good junkyard near me so I'll go pull a few parts there. I also noticed that it has the most problems when it's hot outside. Yesterday it was over 100 degrees here and I almost didn't make it home. It could barely do 40 mph and wouldn't accelerate. But it drove just fine in the morning when it was cool.

 

[BuickGirlFromMars]

Awesome, thank you. I have a good junkyard near me so I'll go pull a few parts there. I also noticed that it has the most problems when it's hot outside. Yesterday it was over 100 degrees here and I almost didn't make it home. It could barely do 40 mph and wouldn't accelerate. But it drove just fine in the morning when it was cool.

That can be the ignition and it can be other things. if you upgrade to the igniiton coils like you see, youll also have a plug gap of .060 and youll need to use new plug wires and youll need new plugs. i cant say 100% but if you wanted irdium long life, 41-101 is your part number. but if you wanted to buy one copper that crosses to that and ensure its the same thread and reach into the cylinder (compare to a new plug for your year)

 

[Superslug360]

Well, I got part of what I needed at the junkyard today. They didn't have any Series I engines at all, but I pulled an ignition module from a '94 Oldsmobile. I didn't get a bracket either, but I think I can fab one up pretty easily.
I took a picture of my old ignition module, it's kind of hard to see from the image but the corrosion near the studs is over an 1/8th inch deep. I also got a picture of the new coil. Hopefully that's all it is, but who knows!

https://imgur.com/a/G3i4n8e

 

[Superslug360]

I ended up modifying the old bracket to fit the new ignition module. I used some helicoil and a piece of sheet metal, and the module seems to fit fine. The car runs fine, I haven't done a long road test yet but it drove fine for a couple miles today. The new ignition module didn't fix the tach, but I already suspected that. I'll report back once I get a chance to do a longer drive with it!

https://imgur.com/a/v5AO6ID