Help with 2000 GTP -- engine sputtering

[cartman68]

First, let me say I am just getting into working on this car, I do simple stuff but I feel I am mechanically inclined and rather do my own work when I understand the problem. Please bear with my novice understanding of this vehicle.

I need help figuring out a problem with the 2000 GTP. For the last few weeks, there has been and increased whining noise. At first we thought it sounded like a fan rubbing against plastic, or a blower. We took the car the dealership when the check engine light came on, but it was off after we got there.

Those clowns took our $98 troubleshooting fee and said that the transmission was causing the noise.... never mind we told them it was something that got louder when increased throttle "in nuetral" and driving. So basically they told us the transmission is going out on the car.

Yesterday, I tried to figure out where the noise really was coming from, and had the wife start and stop the engine while listening. The best way I could describe the sound is: A wire brush rubbing against metal, or imagine a fan blade rubbing a plastic housing. so when the wife turned off the engine, the sound continued for a second and sounded like it was coming from the supercharger. like something was spinning down or the other thing that came to mind was something de-pressurizing.

I hope that is descriptive enough for some ideas.

So, I went ahead and replaced a tensioner pully that had started squealing and after doing we noticed the car started sputtering and died once when I came to a stop.

The MAF was replaced about 4 mos ago. And when unplugged it didn't seem to make a difference.

Drove the car last night and seemed ok, but I noticed when I entered the interstate and layed on the throttle, the boost indicator only went to the second level. So I went WOT a couple of times and it still only bounced between first and second level on indicator.

Then on the way home, while steady throttle on the interstate going 75mph, the car downshifted boost indicator jumped to 75% and stayed there for two miles until we exited. The car ran rough the last few miles to the house with the tach bouncing up and down and the car was bouncing between second and third gear. We thought it was going to die but we made it home.

I am wondering if it is a sensor that went out??

Please let me know your thoughts, and thank you in advance.

Regards,
Bill AKA Cartman68

 

[TDCRacing]

The map sensor is what controls the boost reading on the DIC ( Digital information sensor) IF that comes unplugged (espcially the vacume line) that can cause the car to act real funny. It will also cause the boost reading to stay at a certain point.


Make sure you don't have a vacume leak there. It's the little black box that is by the fire wall with a vacume line and a three wire electrical plug going to it. Also, the plugs are known for breaking. So that may be one of the issues.



As for the noise, It sounds like it may be something in the belt line causing it if it was still happening when the engine was shut off it was still making the noise. It also could be a countless number of other things. It's possible it could be the transmission. It's just hard to say. Even if you posted a video or sound clip that may help up pin point the noise. But it's still hard to find these things without being there.


Let us know any more info or possible things it might be.

 

[josh]

To eliminate the noise coming from the SC you could pull the belt off and drive the car to see if the noise went away. Just be prepared for the car to have no power while the SC belt is off. I would take the car to Autozone and have them scan it for codes. I think it's free.

 

[cartman68]

Thanks for the suggestions. I will try to get a vid posted tomorrow. And check on getting the car scanned.

 

[cartman68]

Update, problem solved. -------------

So, after taking it to the dealer and not getting a reasonable answer, I took it to Advanced Auto for check the code. The guy working there was excellent. The code stored was MAF sensor. The car had been running rich. I showed him where the noise was coming from and he found the vacuum line was not connected under the supercharger pulley. basically the T connector had rotted and broken. All of the connections on that line were brittle and cracked.

So after getting free vacum hose and buying about $2 in T connectors the car was running 100%. We bought a MAF sensor but since we just replaced it back in December, we are holding out to ensure the vacuum line was the issue for a week. If it is not needed we will return in.

I am going to make sure the plugs didn't get fouled.

Thanks for the suggestions.

Regards,
Bill --AKA Cartman68--

 

[blueguy]

Update, problem solved. -------------

So, after taking it to the dealer and not getting a reasonable answer, I took it to Advanced Auto for check the code. The guy working there was excellent. The code stored was MAF sensor. The car had been running rich. I showed him where the noise was coming from and he found the vacuum line was not connected under the supercharger pulley. basically the T connector had rotted and broken. All of the connections on that line were brittle and cracked.

So after getting free vacum hose and buying about $2 in T connectors the car was running 100%. We bought a MAF sensor but since we just replaced it back in December, we are holding out to ensure the vacuum line was the issue for a week. If it is not needed we will return in.

I am going to make sure the plugs didn't get fouled.

Thanks for the suggestions.

Regards,
Bill --AKA Cartman68--

Yup...good ol' dry rot. Happened to me everytime I changed LIM gaskets on a 3800 powered car:th_shakinghead1:

Good deal you got it figured out