01 Century Problem - Car Accelerates on its Own - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 10-20-2012, 09:54 PM   #1
Junior Member
Thread Starter
 
Join Date: Oct 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
drog929 is on a distinguished road
Default 01 Century Problem - Car Accelerates on its Own

I recently acquired a used 2001 Century with 252,000 KM (or 156,00 Miles). It is good shape and runs very well.

However recently I noticed a problem with car continuing to accelerate on its own even though my foot was NOT on gas pedal (just like it was in cruise control mode). The car can maintain the same speed for many miles with my foot off the brake pedal. When I brake to slow down, the car would again accelerate again on it own after I release the brake. I tried manually activating cruise control ON and OFF to see if this would correct problem but no effect. I noticed same acceleration problem occurred at even at slower city street speeds. When arriving at my destination and puttng car into PARK, I noticed idle was revving high.

This problem has happened twice in same week. At other times car drives normally. I don't think my problem is the same as "sudden acceleration" problems that plagued Toyota since my car does not lurch forward.

I see on internet that others have similar "auto acceleration" problems like mine but I have not seen any solutions mentioned.

Can anyone suggest a solution?
drog929 is offline   Reply With Quote
Old 10-20-2012, 10:24 PM   #2
Retired Administrator

True Car Nut
 
GunsOfNavarone's Avatar
 
Join Date: Apr 2009
Location: Williamsport, PA
Posts: 2,856
Thanked 167 Times in 129 Posts
GunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud of
Default

You need to have a certified mechanic look at this before driving the Buick again.

With that said, the first thing I would do would be to remove the floor mat. Start simple.
GunsOfNavarone is offline   Reply With Quote
Old 10-21-2012, 12:29 AM   #3
Senior Member

True Car Nut
 
WilliamE's Avatar
 
Join Date: Jun 2011
Location: VA
Posts: 3,087
Thanked 418 Times in 376 Posts
WilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond repute
Default

I agree with Michael, do not drive it till the issue is found, and fixed.

A lot of carbon buildup could be causing the throttle body butterfly valve to stick a little. get some throttle body cleaner and see if that helps, if you drive it afterwards to test it, I'd stay off of any main roads, and not go too fast, as if it is not fixed, and gets worse, then you could end up getting in a wreck, so be SAFE!

Check the IAC also, remove it, and inspect its pintle for carbon buildup, if dirty clean it.

If that does not help, I'd check for any possible vacuum leaks, listen for any hissing, and inspect all the vacuum hoses.
WilliamE is offline   Reply With Quote
Old 10-21-2012, 01:23 AM   #4
Senior Member
Posts like a Supercharger
 
viniepooh's Avatar
 
Join Date: Dec 2010
Location: MIchigan
Posts: 177
Thanks: 0
Thanked 1 Time in 1 Post
viniepooh is on a distinguished road
Default

id like to agree w/the guys, specially WilliamE, specially in regards of IAC. If u dont know what IAC is, its an idle air control motor, it sits on your throttle body. It happen to me, but much more violently then u described. I was driving my Lincoln Mark VII when it went crazy. It decided to open on me as i was approaching a red light, car basically went from 40 to 70 and i had to shut it off on a road to stop it.
viniepooh is offline   Reply With Quote
Old 10-21-2012, 01:34 AM   #5
Senior Member

True Car Nut
 
WilliamE's Avatar
 
Join Date: Jun 2011
Location: VA
Posts: 3,087
Thanked 418 Times in 376 Posts
WilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond reputeWilliamE has a reputation beyond repute
Default

Another thing, I do not mean to to get off topic, but I noticed your mileage, at that mileage, if you have never had the lower intake gasket changed, I'd suggest planning to do that in the future, your 3.1L LIM gasket is made out of the same known to fail nylon 6,6 just as the 3.8L nylon 6,6 LIM gaskets fail, replace them with Fel-PRO'* aluminum framed LIM gasket.


Let us know how it runs after cleaning the throttlebody and IAC.
WilliamE is offline   Reply With Quote
Old 10-21-2012, 05:22 AM   #6
Senior Administrator


Certified Car Nut
 
Mike's Avatar
 
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,641
Thanked 995 Times in 772 Posts
Mike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond repute
Default

I agree with everyone so far. Check for vacuum leaks. If you find nothing out of the ordinary, I suggest taking it to the dealer and having them run a diagnostic. Usually about $75.

I can only think of a couple things what would cause a high idle condition..
A. IAC-could be sticking too far open
B. Vacuum leak
C. Faulty TPS
D. Throttle plate not closing all the way.

When you are in Park or neutral, what does the engine idle at?
Mike is offline   Reply With Quote
Old 10-21-2012, 09:02 PM   #7
Junior Member
Thread Starter
 
Join Date: Oct 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
drog929 is on a distinguished road
Default

Thanks for all your suggestions. To answer Mike1995 question, when car was in PARK with this problem I didn't take note of the rpms but it was reving noticeable louder.

Before seeing all your comments I decided to I clean the throttle body with throttle body cleaner. I did not remove the throttle body but just cleaned as deep as I could with throttle body cleaner and rag. The front of throttle plate looked pretty clean but the back of the plate and behind was quite dirty and black. The throttle cables seem to be in good shape. I did not remove or check the IAC but after seeing your comments I will look at that tomorrow. After cleaning throttle body I drove the car around the block a few times and car seems to be running normally.

I think I would feel more comfortable taking to a dealer to analyze. Does the dealer have special diagnostics tools to analyze this problem and identify IAC or vaccum leak? I'm worried that they won't be able to replicate problem.

______________________

2001 Buick Century Limited
drog929 is offline   Reply With Quote
Old 10-21-2012, 09:42 PM   #8
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

they can use their tech2 to actuate the iac but you can take a look same as they can. and for vacuum take carb or tb cleaner and spray around suspect area with the engine running and listen for the engine to change pitch
jwfirebird is offline   Reply With Quote
Old 10-21-2012, 11:27 PM   #9
Junior Member
Thread Starter
 
Join Date: Oct 2012
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
drog929 is on a distinguished road
Default

Do I have to remove throttle body to get to IAC? or can I remove IAC only. I cleaned throttle body without taking off because I didn't have a new throttle body gasket. I have to order from dealer and apparently it will take a couple of days to get delivery.

Also using a process of elimination if I remove the fuse for Cruise Control will this disable only the Cruise Control function or will it affect anything else? If the acceleration problem re-occurs without the fuse then can I reasonably assume that cause of problem is not caused by a defective or intermittently working Cruise Control lever?
drog929 is offline   Reply With Quote
Old 10-22-2012, 07:37 AM   #10
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default



should be screwed into your tb.

as far as cruise i doubt that has anything to do with it but they still had cables for the actuators until the 3500 so on yours you could just remove the cable from the tb
Attached Thumbnails
01 Century Problem - Car Accelerates on its Own-3-13-4iac.jpg  
jwfirebird is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Car accelerates by itself Chevy_Impala Chevrolet 6 08-16-2013 11:15 AM
Man I cant wait till I own my own house.... BonEvilSSEi Lounge 9 12-21-2004 08:16 PM
My alarm has a mind of its own jachin Everything Electrical & Electronic 10 02-27-2004 10:26 AM
Doorlocks, trunk has a mind of its own! bonnie90se 1987-1991 6 09-21-2003 10:05 AM
My Sunroof has a mind of its own! drw7162 1992-1999 2 11-14-2002 12:05 AM


Tags
acceleration, cruise

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:50 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.