2001 Chevy Monte Carlo, 3.4L, makes squealing noise when gas is pushed driving or not. Replaced EGR valve, because there was a code for it. When driving it is VERY sluggish, and I have to let off the gas to let it shift. Belt looks new, and took off belt to make sure everything moves freely, water pump, power steering, etc. The squealing comes from the back side of the engine compartment, down the firewall. Is this the transmission? Or am i missing something else?

 

Hi PettyOfficerJason, & Welcome to the MCF Family.
Sorry to read about your problem. From your words and where it is coming from it sounds like it could be trans problems.

How many miles on your Monte ?
When was your trans serviced last ?

Please check back and see what our Expert Tech Member's post when they view your post question.

Wish you good luck in resolving your prob. Please post as much infor to your problem that you can.

 

just to locate problem, either use a can of WD-40 or a bar of wet soap, and apply to the belt while its running, the bar of soap be careful and press up against belt

this lub's the belt and if it stops squealing its the belt and you replace it.

you believe its not the belt but that eliminates it completely and the belt returns to normal after 24 hrs.

as far as tranny is concerned i would check the fluid and if it needs a service i would take it to a tranny specialist shop for a tranny service. If the car has been hotrodded its probably the drive clutch pack going out. Typical 65E problem. the early models were not ment for speed or torque like the 05 and later editions.

But again I would like to mention that transmissions should be diagnosed by a tranny expert and thats why i recommend checking fluid and taking to them. if it is the tranny its probably expensive, but the tranny shop should be able to tell you

 

Intermittent Harsh Shifting / Pump whining, Possible Code P1811:
This is perhaps one of the most common problems with this transmission. It has been a problem since the release in 1997 and can happen for no reason at all even with clean fluid and very low mileage. The EPC solenoid is probably bad and again is very common to happen. The EPC solenoid controls line pressure and has a spool valve which oscillates back and forth to regulate transmission line pressure based on commanded pcm signals dependant on lots of various inputs of the vehicle. The spool valve in the solenoid will bind up and cause loss of pressure control from the pcm. The pcm constantly monitors shift timing in milliseconds and if this is not within programmed parameters after a few shift cycles the pcm triggers trouble code P1811 which is Max Adapt / Long Shift. This code will not set the SES light but will dissable all adaptive shifts and will max out line pressure in the transmission which causes the harsh shifts and can also cause the transmission pump to whine because it is supplying fluid at a high rate and pressure and puts more stress on it thus creating the whine. Generally shutting off the car will make this condition go away until you drive a few more miles or the vehicle warms up and the harsh shifting will return. Replacing the EPC solenoid will most likely correct this condition and again is probably the most common problem found in any year of this trans. I will also add that a worn out transmission can cause this. If the fluid looks bad, dark, and smells burnt or lots of fine dark sludgde or a dark film of material is in the bottom of the pan then there is probably internal damage. Once clutches become burnt and have excessive wear shift timing will be greatly extended and the pcm will fall outside of its set parameters and code P1811 will turn on, again commanding higher line pressure and harsh shifts but an overhaul in this instance is the only proper fix.


Loud Whining, changes with engine speed:
This is another common occurance in this transmission and has a lot of different possibilities. There are a number of different bearings that can fail inside the transmission and each one will dictate when the noise is happening. There is a thrust bearing inside the torque converter that can also make a whining noise and is loudest under a heavy load. Generally that bearing will get louder each time the transmission shifts into a higher gear and the converter has to work harder and puts more stress on it. It wont make noise at idle or in neutral unless the entire torque converter is in very bad condition and has lots of metal in it. The most common bearing whine noises comes from the roller bearings that support the drive and driven sprockets which the drive chain rides on. They will make noise any time except sitting still in any gear, that is because nothing inside the transmission is spinning at this time. In park and neutral they do spin and when the noise is most visable. There are quite a few other bearings inside the trans but these are the common ones found bad.

Courtesy of http://tripleedgeperformance.com/4T6...sion_Info.html

 

...Member `MonteDriver, great post information, Thanks for finding/posting sharing...I also learned from your post.

It's great seeing member's helping member's for sure....
It's just like family

Member ChiefPettyOfficer`Jason, Hope it helps you & your Monte...Peace/Out