Vibration Problem

I just bought a 95 Monte Carlo with 81'000 km on it and it is in great shape inside and out my wife loves it and my son absolutely loves it because in a couple of years it will be his(we hope). I'm hoping somebody has had the same problem as I'm having, when you are trying to drive the car at a constant speed, we will say 100kph and you just try to accelerate a little you get a vibration that seems to run down the centre of the car and if you let off the gas or accelerate harder it goes away and like I said it happens at almost any constant speed, any help or suggestions would be greatly appreciated.

Thx khno.29

sounds like plug wires, i'd probly change the plugs and wires especially if they look original. and at that low of mileage it wouldnt surprise me.

now it could be something more serious, but its a place to start.

Thanks for the reply. I got the car with a 30 day warranty so I'm hoping to go in there with some idea of what might be going on, I,m curious what makes you think the Plugs and wires, I never would have thought of that. I was thinking something to do with the exhaust because their is also a bit of a noise (which I don't think I mentioned in my original question) again thanks for the reply, I think I am going to enjoy this sight.

Have a great day BILL

...just from past experience, under an engine load like what youre talking about is where u generally first see a misfire due to plug wires. the misfire would also cause quite a change in the exhaust sound.

Thanks again, I'm taking the car back today, should pick it up within a couple of days will get back to you.

Thanks BILL

i can't see plugs and wires causing the car to vibrate, especially with only 80,000 km on them, thats less than 50,000 miles, i just can't see wires and plugs causing the car to vibrate, my first guess would be exhaust , cat converter probably

50k me niether, 12 years is a different story. if the wires were the cause of a misfire, the miss would cause a vibration, especially noticeable at say 60mph with the TCC engaged. if the problem was the cat why would it be better when accelerating harder?

quote:

ORIGINAL: 2000LS

50k me niether, 12 years is a different story. if the wires were the cause of a misfire, the miss would cause a vibration, especially noticeable at say 60mph with the TCC engaged. if the problem was the cat why would it be better when accelerating harder?

because it would be getting hotter, your car runs a lot better when the catalytic converter is hot. if it was a miss in the spark plugs though it woudln't get better the faster you go either i dont think, i think it would get worse.

with a light engine load the engine runs more lean than when accelerating, because its more lean more voltage is required to start the spark. cruising under a light load are just the the conditions where if your plug wires have high resistance or can ground out anyway but across the gap they will cause a miss. and what would cause a vibration from a cat anyways?

ok, now i know what your talking about with the plugs


i've just heard of cat's causing that, could be on the go and pluged and running really rough

just depends on how bad the vibration is i guess

sounds like you may have a slight misfire at the speed you have.  it may depend on the load that the misfire is occuring at. 

hey, i don't have a vibration on my monte but yours is hot, nice... does it get hot while in car cause its black,hard to maintain it clean huh.