Shaking Car (spark plugs, fuel, brakes, tires)

[Anamandy]

One of the cars I am driving is my mother’s 1987 ChryslerLeBaron that had 6K miles on it when she died. She always maintained it, kept it garaged, and as a result, is in good shape. Zero rust on the undercarriage and enginelooks new. I still keep it garaged. It now has 27K miles on it. Over the pastseveral weeks I have been driving mechanics crazy because they can’t seem tofigure out why the car is shaking as soon as I turn it on. I brought it back to the shop and they balancedmy tires. Problem still happens. Gets worse the faster I go. I feel thevibration in my seat and the steering wheel. The shaking is predominately inthe front passenger side but the whole front end shakes. Seems to be worse whenit is hot and humid outside or very cold outside. Mechanic checked the tires for wear (only 21Kmiles on them but they are switched to winter every fall so even less wear thanthat) and broken belts. Also checked the rims. No problems found. Had the shocks changed lastyear. We are at a loss. The mechanicdoesn’t think it has anything to do with the bearings. I do hear a slight(road?) hum but always associated that with the tire going over the roadsurface and the hum doesn’t get loader or softer. No noise with turns. Sometimes I hear what sounds like a lub dubdub noise coming from the tires but mechanics say tires okay. Any idea whatcould possibly be going on here? I really don’t want to throw any more moneyinto an older car but the car is now a classic and in good condition otherwise.I would hate to get rid of this blast from the past. Also, can anyone recommend a good mechanic inthe Glens Falls area? I’ve been usingSears and Mavis and like I said, their mechanics can’t seem to figure out whatthe problem is.
Things checked already
Tires - balanced and had alignment done but no change
Brakes - good - no warped rotor and no stuck caliper pins
Wheels - rims good and wheels not bent
CV Axle good
Sway bar stablizer good
Drive Shaft good
Belts -all good
Engine Mounts - good
Other things checked I can't remember off-hand

[froglipz]

Its most likely tires, are they original? See following link about tires as they age.

http://www.edmunds.com/car-care/how-...our-tires.html

[Hemlock140]

Originally Posted by froglipz

Its most likely tires, are they original? See following link about tires as they age.

How Old - and Dangerous - Are Your Tires?

I agree. With tires that old that have sat a long time in one spot, the steel belts in one or more tire could have flattened. You might not be able to see that upon inspection. You can try rotating and see if the shaking moves to the back, but if it were me, I'd just go get a new set.

[Anamandy]

Originally Posted by froglipz

Its most likely tires, are they original? See following link about tires as they age.

How Old - and Dangerous - Are Your Tires?

No, all the tires have been changed about 3 years ago. They are also switched off every fall for studded snows until end of April. Like I said, all mechanics said tires are good.

[mp775]

You said it starts shaking as soon as you turn it on... you mean before you even shift out of park? That would rule out anything involving tires, brakes, suspension. If it's shaking while standing still, I would start with a bottle of fuel injector cleaner and a new air filter; clean or replace the MAF sensor if that doesn't do the trick; and finally try new spark plugs and wires. It could also be a vacuum leak.

[Anamandy]

Thanks mp775. Yes, it starts shaking as soon as I turn it on before I even shift out of park. I had a tune-up and they told me they replaced the air filter and changed the spark plugs and wires, amongst other things done during a tune-up. I don't know what a MAF sensor is but would that be something that would be done during a tune-up? This is an 87 Chrysler LeBaron. Does it even have a fuel injection system? I thought it was a carburetor? Maybe carb cleaner instead? Sorry, I don't know much about cars.

[Labonte18]

MAF = Mass Air Flow sensor..

It likely did have EFI vs a carb.. Which, is actually a bad thing, because the carb would be a good thought as to the problem.. Something sitting that long could have all kinds of problems with the carb, just from not being run.

Possible that the fuel injection could have a similar problem.. But.. Doesn't really feel like it.

The good news is that you have far less sensors to go bad on that thing.. The bad news is.. You don't have a computer that will point you to a problem area. If that thing did have OBD, it was OBD1 which didn't track much of anything.

My guess here.. And it's just a guess.. I do show that this car had a MAP sensor.. And the MAP sensor being bad would cause pretty much exactly what you're describing.

[Anamandy]

Labonte, thanks for your imput. The car was garaged but driven almost every day by my mom. She just didn't go any place far. Just to the store and church, all within a 2 mile radius from her home. As far as the MAF, wouldn't one of the mechanics have checked for that?

[johnrex62]

Didn't they start the car after doing the tuneup? Why didn't the shaking become obvious at that time? It really sounds like an imbalance in the engine of some sort. Usually that would be a misfiring cylinder due to spark, ignition or fuel injector etc. A tuneup should have remedied all of those or at least identified a more serious physical issue with the engine that could not be cured with the normal tuneup activities.

If the engine starts shaking noticeably on startup (with the car still) and the tuneup mechanic did not notice it, and the same garage thought the tires or suspension was at fault (on a stationary car)......my first priority would be to find a new garage.

[captne76]

Yep if its the engine generally shaking while you are sitting still going nowhere,,,could even be a simple spark plug cable. If you pull one cable at a time and you get no change,,,there you go.