Hey, Monte Carlo Forums!

I've been on this forum for the last few years and you guys have given me great advice on what to do with this car of mine. But lately this car has been giving me a head ache!

As stated above I own a 2002 Monte Carlo LS 3.4, with about 168000 miles on it. It's runs quite well, but has it's hiccups. Lately it's been running very sluggish and rough. I can't quite figure out why. At idle it runs fairly smoothly, I don't have any of the problems that fellow Monte Carlo owners experience.

For as long as I've owned the car it's had one weird characteristic, when I accelerate it sounds as if there is a fan blowing at High until I take my foot off the pedal. While cruising it rides smoothly. But lacks passing power and has a bit of hesitation when you try to accelerate from any speed. From a stop light it has an appropriate amount of acceleration and power until about 20-25 MPH then it's acceleration drops drastically and feels like I have a 5000 lbs load on me. That's where I get stumped at.

I've went through everything on the Intake and Intake Manifold. I've cleaned all the sensors that could be cleaned. I cleaned the EGR Valve on the intake manifold. (It was full of carbon). I get regular oil changes, and replaced the air filter. I have no leaks.

So what I don't understand is why is my engines performance so terrible and what is this crazy noise coming from the engine bay?

Please help a fellow Monte Carlo owner! I will post a video as soon as possible.

 

Hey! From what I'm seeing here. When was the last time you had your catalytic converter changed? If I'm not mistaken, lacking passing power at speed is a cause of a bad cat.

Might want to look into a tune-up to if you haven't done it already. Intake Filter, Fuel Filter, Plugs and wires, etc.

 

While you at it might wanna see what's up with the sparkplugs