2000 Pontiac Trans Am, weird clunk during acceleration, and oil temperature gauge fluctuating. problem?

Question

2000 Pontiac Trans Am, weird clunk during acceleration, and oil temperature gauge fluctuating. should i be concerned?

2 problems. The first is that when u step on the throttle, a half second later there is a clunk that seems to come from the back of the car, maybe the axel. its only noticeable during low speeds, but that may be because the engine and road noise is so loud when u go faster. its most noticeable when u speed up, then let off the gas to coast or whatever, then press it again. the car jumps a little, but i think that may just be having a big engine turning everything.

second is that the oil temp gauge goes from the normal halway mark, then when u accelerate it sometimes goes up to 3/4, stays there for a few minutes then goes back to normal. happens randomly, mostly when u first get in the car.

Thanks!!

Answer 1

The "clunk" might be a bad u-joint.
The oil pressure problem sounds normal, but dirty oil might cause the pressure regulator to stick a little. Have your engine flushed and use synthetic oil.

Answer 2

GM had a problem with the baffles in the gas tank coming loose and clunking during acceleration. If the rear end bushing check out you might consider the tank being at fault. The oil guage problem is not really a problem. When you first start the car, the oil is cold and therefore thicker. During throttle it will rise some what. If it bothers you try an oil that's thinner.
Master tech 40 yrs.

Answer 3

The clunking sound could be a couple things.

1. the u-joints are going bad and need to be replaced. If the u-joints are worn and have slop in them they will clunk on acceleration or deceleration.

2. loose or bad rear suspension components (most likley the cause) i have had 2 cars with this problem and a few friends. have had the problem in ford mustang, subaru impreza, and mazda rx-7. the problem the rear struts or sway bar is loose or damaged.

3. brake component loose or disc pad cracked



The oil temp guage sounds like either the guage itself or the sending unit is bad or there may be a bad ground. The ground is the easiest to fix and is free. turn the engine on and play with the wires in the dash and see if the needle moves next play with the sender unit wire under the hood and have someone in the car to watch the guage.

Answer 4

You have a problem in your Differential.Your case Pinion Gears and side Bearings may be worn.Clunk noise is diagnosed in that area.
In respect to the Oil Temp Gauge.Either you have a defective Oil Pressure gauge,or your cam shaft lobes are worn.Your push Rods sit on those lobes.Also the Oil holes that allow oil to the Cam and Crankshaft Bearings may be patially clogged.