gas mileage still not great - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


2000-2005 Discuss your 2000-2005 Bonneville SE, SLE, and SSEi Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 11-10-2005, 10:39 PM   #1
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Sep 2005
Location: medina, ohio, united states
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
nwtflogan is on a distinguished road
Default gas mileage still not great

ok first i want to say this is a fantastic site.i recently purchased a 01 ssei with 42k and got he gm pp warranty, my wife is only getting 19mpg on the highway and ive tried premium gas and change the fuel filter just for kicks, as a car salesmen ive seen these cars gaet alot beter gas mileage, usually at the leat 22 on the highway, any ideas here.
i still fell the torque convertor is not locking up properly and killing me but any ideas would be great. the car is as straight as a arrow no signs of any misuse at all.
nwtflogan is offline   Reply With Quote
Old 11-10-2005, 11:31 PM   #2
Senior Member
True Car Nut
 
Join Date: May 2003
Location: Lethbridge, Alberta, _______Canada._______ West Coast Bonneville Fest ___05,06,07 Survivor___
Posts: 8,134
Thanks: 0
Thanked 0 Times in 0 Posts
SSEimatt93 is on a distinguished road
Default

Well to diagnose TCC....what RPM is your engine at say 75mph? Most run around 2000. Other than that, i would do the plugs, wires, 02 sensor..both of them if you can...that kinda thing...
SSEimatt93 is offline   Reply With Quote
Old 11-11-2005, 12:48 AM   #3
Junior Member
 
Join Date: Aug 2005
Location: North of Buffalo, NY *** NEBF '05, '06, '07 *** ***ONBF & NYBF 06; 07*** ***WCBF 06***
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
singscountry1967 is on a distinguished road
Default

I had to replace my plugs/wires at 43k on my 00 SLE....increased city mpg from 21 to 24...over the road I get 31.
singscountry1967 is offline   Reply With Quote
Old 11-11-2005, 11:27 AM   #4
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Sep 2005
Location: medina, ohio, united states
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
nwtflogan is on a distinguished road
Default

im running about 2000 at 60 and the slightest increase in acceleration takes my to 25-2700 rpms
nwtflogan is offline   Reply With Quote
Old 11-11-2005, 02:01 PM   #5
Senior Member
Posts like a Camaro
 
Join Date: Sep 2003
Location: Bad Axe,MI.
Posts: 1,025
Thanks: 0
Thanked 0 Times in 0 Posts
daman is on a distinguished road
Default

Air filter
plugs
o2
tires are topped off,
junk out of the trunk

know anybody with a scan tool, they can check it for ya,to see if the TCC is working
daman is offline   Reply With Quote
Old 11-11-2005, 02:14 PM   #6
Senior Member
Posts like a Turbo
 
Join Date: Dec 2004
Location: East Texas
Posts: 242
Thanks: 0
Thanked 3 Times in 2 Posts
Ivory03 is on a distinguished road
Default

Quote:
Originally Posted by nwtflogan
im running about 2000 at 60 and the slightest increase in acceleration takes my to 25-2700 rpms
That does sounds like your TCC is not kicking in like SSEIMatt93 is saying. I don't know if something is not telling the computer to kick in such as a bad/disconnected engine temp sensor (thinking the engine is always cold) or the plug is disconnected from the tranny. I use to know everything about the overdrive/TCC on early/mid 80'* cars, but these I am foggy on. Maybe someone can chime in on some ideas..
Ivory03 is offline   Reply With Quote
Old 11-11-2005, 02:19 PM   #7
Mark Fahey
Guest
 
Posts: n/a
Default

The torque converter doesn't lock up until the engine is close to operating temperature. In fact, what is different about these converters is that they progressively engage depending on temperature. I took mine back when it was new absolutely convinced that the transmission was slipping when it fact, it really was acting normally.
I have a 44 mile commute that usually has some stop and go driving and average from 26-27 in the summer to as low as 22 in the winter but never less than that. My average this week has been just over 25.
To help decide if your transmission is acting properly, once it is warmed up, accelerate and count the gear changes. The converter should lock at 45 and you should then see 35mph/1000rpm so using your example of 60mph, you should be reading around 1700rpm. It sounds to me like you aren't getting out of 3rd. I'll try to remember to check mine on the way home to see what the rpms are in 3rd gear.
  Reply With Quote
Old 11-11-2005, 02:30 PM   #8
Senior Member
Posts like a Camaro
 
Join Date: Sep 2003
Location: Bad Axe,MI.
Posts: 1,025
Thanks: 0
Thanked 0 Times in 0 Posts
daman is on a distinguished road
Default

Quote:
Originally Posted by Mark Fahey
The torque converter doesn't lock up until the engine is close to operating temperature.
YES..... but if he has a buddy with a scan tool(with live data capabilities) you can take it for a drive and see if the ECM is commanding the TC to engage.
then you will know for shure
daman is offline   Reply With Quote
Old 11-11-2005, 07:56 PM   #9
Mark Fahey
Guest
 
Posts: n/a
Default

I checked on the way home tonight and in 4th gear with the torque converter locked, the engine was at 1650rpm at 60mph. In 3rd gear it was 2350.` Keep in mind that your gear ratio is numerically a little higher than mine so factor that into your thinking. It still sounds like something isn't right with the transmission.
  Reply With Quote
Old 11-12-2005, 09:01 AM   #10
Senior Member
True Car Nut
 
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Thanks: 0
Thanked 0 Times in 0 Posts
Rogue is on a distinguished road
Default

Most trans codes will NOT light the SES light. Your best bet is to have the car scanned for codes and proceed from there. To check your 02 sensor let the car warm up and while checking the 02b2 millivolts it should waffle low to high rapidly. If it doesnt you will want to replace the 02 sensor.
Rogue is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Changed my fuel level sensor and gas gauge still not working! Overdrive 2000-2005 6 07-21-2014 12:46 PM
Great uncle broke the family's mileage record! Bonneville92V688 Lounge 7 04-11-2007 07:01 PM
Gas, Oil And Gas Mileage **** SERIES II ENGINES**** Nashville Cowboy General GM Chat 26 02-06-2007 06:23 PM
Mileage still killing me! LuxuriesPremier 1992-1999 29 09-02-2005 05:57 PM
not good. NOT GOOD. (hit and run, not bad-BAD, but not good) repinS General GM Chat 13 11-26-2004 11:35 AM


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 04:45 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.