2001 Buick Century 3.1 66k miles, Very sluggish

[TGP37]

They are expensive for an exhaust part.

[bigboi407]

Depending on how the MAP failed, yes it can cause a rich condition. But the PCM has a catalytic over temp setting that controls max AFR per airflow mass. Not sure how a MAP failure would play into that. Cat protection is coolant temp based. I suppose it is possible to run too rich while having a normal ECT.


If you really do suspect the car driving extra rich for a long period, checking the CAT is a good idea.

No need for performance cats on a stock dd. Plus the cat has a part in muffling the exhaust. A smaller CAT may be a little cheaper, but they are a little more raspy sounding too.

im sure she wouldnt mind any noise difference, neither would i, i can get the magnaflow for $170, which is about $45-80 cheaper than all the other ones i seen, AZ wants $245 for one, too much $$$ for a cat, imo

[TGP37]

Depending on how the MAP failed, yes it can cause a rich condition. But the PCM has a catalytic over temp setting that controls max AFR per airflow mass. Not sure how a MAP failure would play into that. Cat protection is coolant temp based. I suppose it is possible to run too rich while having a normal ECT.


If you really do suspect the car driving extra rich for a long period, checking the CAT is a good idea.

No need for performance cats on a stock dd. Plus the cat has a part in muffling the exhaust. A smaller CAT may be a little cheaper, but they are a little more raspy sounding too.

[bigboi407]

You could try unbolting the cat and visually look inside with a flash light. When cool of course.

she did drive the car with a bad map sensor for quite some time so im guessing the excess fuel caused the cat to fail... im gonna change the fuel pump Anyways, cause she bought one so that will be done next... and should i go with the magnaflow or get a different cat?

its still throwing a cyl 1 misfire but doesnt do it all the time, new wires and new plugs, i could try moving the coil pack over see if it follows, but someone was telling me depend on how clogged the cat is, it could be causing ALL these problems

[TGP37]

You could try unbolting the cat and visually look inside with a flash light. When cool of course.

[Fireball]

i was talking to someone and i guess i cannot run it without the cat due to the 2nd o2 sensor or something of that nature, is this true?

i did notice the car runs perfectly fine until a certain point then i hear the noises and it doesnt wanna go anywhere, also runs much hotter than it used to, you guys said that something would have had to clog the cat, well her map sensor was bad for Months before i changed it, could that have clogged the cat? were gonna change the fuel pump anyways considering it was $50 and the fuel filter it had before was clogged up

Can i use the magnaflow cat? shes gonna buy a cat next week

When i dropped the transmission pan the magnet had alot of metal built up on it, a bit too much for 68k miles and being opened once already, you guys think i should hunt for a transmission? i myself dont like A/T's thats why i dont own a buick ATM

Dude, that clicking in the first vid sounded almost like the egr! There was a video of a guy here testing the valves with a battery but I can't find them...

http://www.youtube.com/watch?v=hpB6CELWYhQ

There are a bunch of vids on youtube, I'm not saying this is your problem, but if it hasn't been checked it may be a good idea to make sure the passages are clear?

[bigboi407]

i was talking to someone and i guess i cannot run it without the cat due to the 2nd o2 sensor or something of that nature, is this true?

i did notice the car runs perfectly fine until a certain point then i hear the noises and it doesnt wanna go anywhere, also runs much hotter than it used to, you guys said that something would have had to clog the cat, well her map sensor was bad for Months before i changed it, could that have clogged the cat? were gonna change the fuel pump anyways considering it was $50 and the fuel filter it had before was clogged up

Can i use the magnaflow cat? shes gonna buy a cat next week

When i dropped the transmission pan the magnet had alot of metal built up on it, a bit too much for 68k miles and being opened once already, you guys think i should hunt for a transmission? i myself dont like A/T's thats why i dont own a buick ATM

[Merc6]

All depends on how the car is maintained. On the freeway* my 109K L82 pulls away from same body style N/A 3800 Buick Regals. I haven't done the LA1 Throttle body or UIM/LIM swap yet either. That's all sitting in the garage for the summer.


*Wasn't a street race but quite a few a$$hats not wanting to be passed up by a possibly slow Centry driver.

[bigboi407]

No power after 1st when floored, happens most times but not all the time.......sounds like ATF issues. Considering a rattling, maybe bad input shaft? idk

But I do know the "sucking" sound when floored is interesting to note.....Reasoning that any leak should be heard more so under a vacuum, not wot where the manifold pressure is almost ambient.

I wonder if you are hearing the exhaust being forced out small passages from a clogged cat or, god forbid, teenagers shoving apples up the tail pipe.

Thats exactly what i was guessing today as i drove it around and the problem seems to worsen, we live in FL nothing about emissions here, whas the cheapest way i can fix her exhuast problem? AZ wants $275 for a cat and a guy on ebay wants $219,

on a side note, the crx i used to drive that i pulled the motor from came with an after market carb, the people that put it on didnt gut the cat out which is right below the exhaust manifold, i always noticed the carb when revved high would vent gas fumes back to the filter, so i found this info out later while building the new engine for my civic that the cats MUST be gutted to run the carb i run... i gutted the cat & Welded the EGR return everything is just perfect now... carb doesnt spit out fumes

i seen a 1991 Buick Lesabre Custom today... i want one i miss my buick, it was much faster than this century, i remember goin up against like a 2005+ maxima, 0-50mph from a green light, i let him go, i told her to sit back in her seat, punched it to the floor the back end went down and i shot off like a rocket past the maxima, until 50mph then i turned, i got this sucker for free had 45k miles when i got it

[TGP37]

No power after 1st when floored, happens most times but not all the time.......sounds like ATF issues. Considering a rattling, maybe bad input shaft? idk

But I do know the "sucking" sound when floored is interesting to note.....Reasoning that any leak should be heard more so under a vacuum, not wot where the manifold pressure is almost ambient.

I wonder if you are hearing the exhaust being forced out small passages from a clogged cat or, god forbid, teenagers shoving apples up the tail pipe.

[bigboi407]

when you sprayed the engine down with carb clean looking for vacuum leaks, did you spray the brake booster and behind the booster? Have someone apply the brake while doing this too. I don't recommend draining the coolant via the radiator petcock. Older cars tend to never reseal once you've disturbed the petcock. Pop the lower rad hose off and drain it that way.

no i didnt do that but ill give it a shot...... i dont understand how it only does it in gear and it doesnt happen every time i hit the gas, but every other time i hit the gas, could it be the fuel system??? i noticed the fuel pump noise while in idle is not stable the sound gets louder then tones down a bit then back up again, but if it was the fuel pump wouldnt it act up at high RPMs?

Best way for me to explain it... lets say you wanna hual ass from a take off, the car will sometmes go but still nowhere near as fast as when she first got it, the car has no pickup after 1st gear, when you hit the gas and your supposed to go, engine roars(She says its ALOT LOUDER than it used to be) but it has barely any advancement in traffic

There was a rotted hose here, i replaced it:


i dont think this is causing a problem:



FPR vacuum connection (Brand new line):


A sort of dry rotted cap (i took it off and blew into it didnt leak, but i will change it ASAP):


i put a new Vacuum elbow here and its perfect:


brake booster hose on intake:


hose connection from booster:



Whats this about??


MAP sensor connection to intake (BRAND NEW HOSE):


Map sensor connection:




I also just noticed while the car is in park and the key is on there is a clicking sound somewhere around the intake, is that normal? it comes and goes, Here is Video of the noise:



My camera that i can upload with can only record 60s videos heres a few so you guys hear how the car is driving, you will have to turn up your speakers to listen in..















she claims its much louder than when she first got it, sounds like something rattling in the intake she says....

Looks like im gonna drive it sometime without the cats in it, someones tellin me all i need to do is change the cats and the problems will go away, said the cats are clogged uponce i figure out how to disconnect the exhaust.... i just disconnect the O2 sensors if i wanna run open header for a few?

[95SleeperAcheiva]

when you sprayed the engine down with carb clean looking for vacuum leaks, did you spray the brake booster and behind the booster? Have someone apply the brake while doing this too. I don't recommend draining the coolant via the radiator petcock. Older cars tend to never reseal once you've disturbed the petcock. Pop the lower rad hose off and drain it that way.

[bigboi407]

After a newMAP Sensor the car drives much better, Only problem left is --> while the car is in motion, if i hit the gas i can hear a suction or spray sound that is coming from the left of the engine bay, the MAF is secured in place correctly, i have replaced the map sensor hose and replaced a few other hoses, where the hell would this leak be... it doesnt happen in Park and it doesnt happen all the time,..... the car shifts much better after a tranny fluid change, it still doesnt accelerate like it should, but i dont know whats causing this car to not take off like it should

Also how do i flush this radiator? i dont see a valve that i can open on the bottom

While driving on the highway 3-4 gear are VERY weak, i changed the fluid and filter, it has the right amount, when i dropped the tranny pan there was buildup metal on the magnet and i noticed a tranny shop tag under the hood and she told me something was done to the transmission when her mom owned it, this is why i dislike A/T's..

[60dgrzbelow0]

This is an interesting link with some owners of the Buick Century Vehicles who, having suffered from the same weird shifting problems, used a a combination of Sea-Foam and the Higher Grade of GM's Dexron VI Transmission Fluid...and managed to solve the bizarre shifting problems without breaking the bank. Read this one thoroughly... because the answers are scattered throughout the entire textings...

http://townhall-talk.edmunds.com/direct/view/.f0e9ec8

As an aside to all this... I wanted to impart a little bit of ancient history concerning the Town of Deltona, Florida. You won't believe this... but back in 1967, I was a high school kid who worked over in Deland, Florida at an old Army Barracks by Sidney Toler Airport ...then owned by Mr. Henry Poppell and called "Poppell's Furniture Galleries". One day I was given an order to deliver a house-full of furniture to a place they were calling... "Deltona"... So I meandered out into a very pretty, rolling hilled section west of Deland and followed a winding, brand new strectch of paved blacktop road out into a clearing where the land hand just been buldozed and numerous concrete foundations had been poured; with the pipes and electric hookups naked for the length of one block. There... at the end of that one row was a single, small dwelling that was apparently...the very first home built and occupied in "Deltona". My partner and I greeted the new owner and then unloaded the truck in the tidy new home...of an elderly, retired female Naval Warrant Officer... I guess she REALLY understood what it meant to "Get in on the Ground Floor" of the then Brand New City of Deltona, Florida!

[bigboi407]

The New MAP sensor has been installed along with a new MAP sensor hose, id like to have said " You guys were Right!!!" But i was infact Correct when i said "I think its a bunch of little problems adding up" It DOES NOT Bog spit cough Etc... Etc... The new map sensor has solved that symptom, BUT there is another problem

When accelerating from a take off, when it gets close to 2nd gear IT WILL NOT SWITCH until the accelerator has been released, if i do not release the accelerator it will rev to its max, that goes for changing into 3rd AS WELL.... once it Actually switches to the next gear it doesnt have any acceleration, will take off pretty quick but once it switches gears the transmission FEELS Very weak, but to me it seems like a pressure issue, its not slamming into gear its just Very Weak when driving in any gear above 1st, the transmission doesnt seem to be Slipping AT ALL, doesnt feel as if something is Damaged You guys got any ideas?

EDIT: changing the map sensor stopped it from doing one thing, but i still hear a leak when i hit the gas really hard..... i dont know where it could be from... im gonna try a few things and see what i can do cause i have no clue how to find this leak it doesnt happen in Park im all out of ideas once i change a few hoses out that DO NOT look bad at all