Thread: Sounds really bad when idle/ Acceleration Delays (Noob)

New member here trying to see if I can get some advice. Would like to find out what I should be looking for hopefully someone can point me in the right direction. I've looked through a lot of other ppl's discussions and it seems that is could be any of the following: CTS sensor, Fan Issues (fuses, relays, etc..), T-stat, LIM gasket, Would any of these cause the knocking sound, and shaking of the car, and overheat. Please Help. I drive a 1997 3.8L V6 GP Naturally aspirated

When I start the car it jumps to 1500 then oscilalates down to 600 rpm three or four times before idling. After about 3 minutes of warming up the car will idle at around 1000 rpm but knocks really bad. Even at stop lights you can hear it knocking, and the car will begin to shake.

While I am driving the acceleration seems delayed. When on the high way if I hit the gas it's almost as if the engine doesn't know that I'm pressing the gas so I lift off the pedal and press down again and the car accelrates like normal. This takes the fun out of driving. If I don't release my foot the first time it just accelrates really slow.

Recently the temperature has been getting up to ut never higher than 210. When I begin to drive ,especially the faster I go, the temperature goes back to normal around 150. Low coolant light comes on every once in a while but not all the time. Everytime I check the coolant it's not low so idk what thats about. Got oil leak fixed, didn't change anything.

I've looked through a lot of other ppl's discussions and I'm starting to think it's a CTS sensor, Fan Issues (fuses, relays, etc..), T-stat, LIM gasket, Would any of these cause the knocking sound, and shaking of the car, and overheat. Please Help

Wow, it sounds like you have several issues here.

Being a 97, I would bet that the lower intake manifold gaskets need to be changed. You say the low coolant light is coming on but is full when you check it? My car used to do this when I would be on the highway. The light would show up, then I would take my foot off and coast for a second or 2 and the light would go out. Back to maintaining speed it would come on again. The system is low. Found that my LIM was leaking and the radiator had a small crack around the neck that would only show up when hot. Of course this let air into the system which would also cause an overheat condition. And BTW, these cars run hot normally and the fans aren't set to come on until around 210, so that sounds normal there.

The bouncing idle could be a dirty MAF, or a bad IAC (Idle Air Control Valve). Try cleaning the MAF with the correct MAF cleaning soultion (comes in a spray can). You will need a saftey t-20 torx to remove the MAF more than likely.

On to the knocking issue. Can you locate where on the motor the sound is coming from? Top end? Bottom end? YouTube search for 3800 rod knock and lifter noise and see if any of those sound the same.

When you try to accelerate and it won't move, do you get a check engine light, or possibly a flashing CEL? It sounds like you need to start with a tune up- Wires, Plugs (NOT PLATINUMS), fuel filter, air filter, clean the MAF and see what that gets you.

Have you pulled the oil dipstick to see if the oil is clean and not looking like a chocolate milkshake? Also check under the oil fill cap for any yellow or white residue. Those are signs that the motor is eating coolant and if you don't stop driving it until you fix the issue you will most likely spin a rod bearing and be looking for a new motor, if that isn't what the knocking sound already indicates.

Good luck and let us know what you find.

Went and got an oil change over the weekend and they told me the noise I am hearing is under my car and that it is a resistor pipe shaking around. He said I would be alright driving around with it I would just hear the shaking noise.

This morning I went to start my car and it wouldn't stay running. I could turn it over push the gas, put it in reverse but as soon as I let off the gas it dies. Then I tried to brake and almost ran into the car behind me. Got it up to the shop and they said it was most likely my EGR valve and that my vacuum lines came undone which is why the car wouldn't stay running. Does ths sound like something an EGR valve would cause? It's still at the shop so it may turn out to be something different. Will update tonight.