OT modern used car shopping

[Young Ed]

Looking at a couple late 90s GM products with 3.8 engines. Just wondering if anyone out there has any must checks. One has in the ad a bad radiator(easy fix) but it also says power steering leaks. Hopefully that would just be a line but if its a rack or the pump are those tough to replace?

[Ed Griffin]

You may want to take a look at the harmonic balancer on them. Dont know about late 90's but mid to earlier Buick 3.8 and smaller engines have what I consider a "recall" condition. Should have had recall's because of this. I personally have had two Buick's with this problem and have heard several others out and about that you could hear that has this same problem. It's a very loud clak clak clak sound as if it's abt to throw a rod or something. Whats happening is the bolts holding the balancer together end up breaking and the plates slide causing the claking noise. I'm not exactly sure what componants are actually coming apart but this is what I could see while inspecting a Century. Just after I sold my 95 Riviera it did the same thing. New owner put another on but mentioned it was'nt cheap nor easy to do. He got a discount from fellow he knew at GM. My in laws also had the same problem with a LeSabre so this is not just a model problem but an engine problem.

The Riviera also had a problem with the secondary gasket on the intake but it had a supercharger on it and could have been just a fluke problem. Broken "plastic" gasket causing a vacum leak.

[Young Ed]

Hmmm My sister had a 90 Bonneville that she drove about 50K miles with a noise like that. We always thought it was a loose timing chain. Perhaps not. Will add that to the list!

[Ed Griffin]

Ed, I still have the Century sitting in the back. My youngest son finally got tired of it and purchased his first car. He drove the Century like that for a long time. It was running when I parked it, lol, but it began to have other problems (electric window..etc) as well so there it sits. Good luck in your search!

[JerseyHarold]

Crank Position Sensor magnets get weak on 3800's causing the engine to die when hot. You have to pull the harmonic balancer to replace, IIRC.

Also the thin antitheft wires going to the ignition lock cylinder (PassKey II with the resistor on the key) break causing no-starts. There is a way around this...PM me and I'll explain.

For what it's worth, my nephew got 300k out of his '87 Bonneville with a 3800.

[Young Ed]

Well ended up with a 97 bonneville for $650 bucks. 138K miles only but its had a few fender benders in its life. Sounds like the bearing in the alternator is on its way out and then it turns over slow at first. Then it goes a little faster and starts. Also the guy only had 1 of those expensive ignition keys.

[JerseyHarold]

$650. is a really good price. Private seller?

[Young Ed]

Craigs list special. Motivated seller needed to get his thunderbird out of impound lot!

[Guest jtw3749c]

I had and do have the Gm 3.8 in a Bonneville and a Buick Park Avenue. Mine have been excellent engines. No problem with the Damper, but do know a friend that did. His mechanic replaced the engine. Talk about expensive, WOW!! Turns out it was the damper. He found out after it started on the second engine. My Bonneville has 168k miles on it and still use it from time to time. Good car. Buick is pushing 112k. I think it is destined to be the infamous Small Block Chevy only in a smaller version... Oh and the stock plenum's are good for about 80 to 90k then they crack. Replaced with an after market that is heavier and thicker... The End....

[Young Ed]

My moms 97 olds 88 lost the plenum at about 40K. It was low mileage with grandpa only driving it about 3K miles in the first 2-3 years. I blame a lot of this issue on dexcool. This car will be drained and refilled with green

[Ed Griffin]

Crank Position Sensor magnets get weak on 3800's causing the engine to die when hot. You have to pull the harmonic balancer to replace, IIRC.

Also the thin antitheft wires going to the ignition lock cylinder (PassKey II with the resistor on the key) break causing no-starts. There is a way around this...PM me and I'll explain.

For what it's worth, my nephew got 300k out of his '87 Bonneville with a 3800.

2 other problematic symptoms I had forgotton about that you brought up Harold. Inlaws Buick LeSabre did the dieing when hot thing. They went through this while under warranty with the dealer several times and all they would do is replace the computer chip. It kept happening and they never got to the bottom of the problem. Wish I had known about the sensor magnets then to save them a lot of trouble. Also to have known about the antitheft wire problem would have been a huge help as well. I had forgotton about the Riviera doing that. Using the dealers manual's I was able to get it good enough to turn over but told the new owner of the problem and let him deal with it.