maybe bad bearing?

**mvp2765** · 10-12-2009

i have a 2000 gp gtp.....i think that the problem has to do with a bad pulley bearing and the friction it is causing when the car is running to make the rpms go up and down in idle...

When i turn on the heat or a/c, the fan is pretty weak, it work sometimes, almost like a flickering light bulb due to me accelerating or driving at different speeds..

I replace the a/c compressor with a different one because the old bearings were bad and you were able to hear the screeching of those bearings...

Now, is there a separate compressor or pulley for the heat, or fan , or what ever blows air into the cab???

Because that is what i think the problem is, a bad bearing connected to the main drive belt.... Chime in if anyone has any ideas??
THanks

**ryanmx** · 10-12-2009

There is a seperate fan to blow air into the cabin, but its electric and more the likely located on the underside of the dash on the passenger side. Just by your description, though, It almost sounds to me to be a bad ground, possibly even battery terminals. It may not be the problem, But it is always a good idea to keep your battery terminals clean. Or, the problem exists either in the fan or the switch or the the resistor. If you have only one speed of the fan, and no other electrical problems, then it will more than likely boil down the resistor used to control the speeds of the blower fan. When the resistor goes i believe it defaults to low fan speed, regardless of switch position. If your fan is hit or miss, as in working occasionally, while it is supposed to be on, your fan is probably on its way out.

**mvp2765** · 10-12-2009

i actually just put in a new battery a month ago...thought maybe bad alternator also, because the car runs heavy in idle always , meaning the rpm's are constantly rev-ing up and down in idle..

-this true even when the fan of the ac/heater is off..

And when i turn on either the ac/heat/fan, the rpms of the engine jump up and down "even more" and feels like the car wants to die, but doesn't...The different speeds of the fan work when it seems there is the least friction...Feels like something is grinding on the main belt which is robbing power to the rest of the electrical components..

Thats the reason i thought maybe there was a fan pulley or heater pulley or something on the main belt other than the ac compressor that would cause this loss of power...another thing is at WOT, the car still goes with power..just at low rpms like near 1k-2k, you can feel something isnt right..

**ryanmx** · 10-13-2009

Okay, have a look at volt gauge when the car is idleing. If you see it wandering a fair bit (should be around 14v +/- .5v) you are probably going to be replacing your alternator. I must have mis-understood your first post, it was kinda late here haha. I would have it checked at your local shop just to make sure it is going. This may also be linked to load or something rubbing on the belt theory your haveing. Usually when the alternator is under a heavy load, you can hear it whistle sort of. A bad alternator May be loading up your engine at an idle, but at throttle the load wouldnt matter much because the engine rpms will just power through the load. Is there any type of belt squeek at idle? At RPM?

Im also just curious though, what kind of A/C compressor did you put on? New? Used? Refurb? The A/C system is usually the biggest load your engine will have to deal with, other the transmission.

Let me Know how things turn out. If your volt meter appears to be okay, you could have other issues, maybe even an EGR issue. Have your Alt checked for sure. You dont want to have to put another battery in because your Alt fried the new one!

**Bio248** · 10-13-2009

if the belts are being dragged down then the volt gauge isnt going to tell you anything. if your system is recharging like its supposed to youll never see it dip down below ~12.5V.

to me it kind of sounds like you have a vacuum leak.

**mvp2765** · 10-13-2009

thanks for the info..i am getting it checked out at a different shop today...I know somethings wrong..my main go-to-shop keeps telling me that the cars running good and i know it isnt...

**mvp2765** · 10-13-2009

these are the codes that were thrown (MAF sensor, Oxygen sensor 1 and 2, boost controller solenoid, and evaporative emissions control system)

Shop said they wanted to start troubleshooting all of these codes that were thrown...I didnt have time to get it done today, but the shop said that these sensors are whats making the car run heavy and rough...

does that sound right????? does anyone think that my PCM might need to be reprogrammed??

**Bio248** · 10-13-2009

might need a new MAF. you could try cleaning yours first.

**chrisb** · 10-13-2009

Originally Posted by Bio248

might need a new MAF. you could try cleaning yours first.

I agree here, make sure to use electronic cleaner or you will be buying a new maf sensor if you use carb or break cleaner!

**mvp2765** · 10-13-2009

going to try and take a look at it tommorrow...if i do need a new MAF sensor, would one off of a 2003 grand prix gtp work fine?? because i have a dead 03 gtp sitting at home..

**Bio248** · 10-14-2009

i believe they are the same, so it should work.

**97gtsc** · 10-14-2009

Sounds like a vac leak?

**mvp2765** · 11-11-2009

finally had the engine looked at..the mass airflow sensor had a blown fuse and one of the spark plugs wasn't gapped correctly..that fixed the heavy idle of the rpms jumping up and down which was my main concern..good to know nothing big had to be replaced..

i also have a broken blower motor or what ever the motor is that blows the air into the cab or interior...i have a working one, just dont know how to install it or where its even located...thats my next mission..Any tips on on how to do this...i realize everyone is going to say search for it, which i am about to do right now!