SaturnFans.com
saturnfans.com - classifieds - forums - webmail


Go Back   SaturnFans.com Forums > Models > Saturn Vue > Vue Tech

Reply
 
Thread Tools Display Modes
Old 07-28-2021, 12:21 PM   #1
EdH
Junior Member
EdH is on a distinguished road
 
Join Date: Nov 2004
Location: New Jersey
Posts: 29
 

2001 L-Series 2.2L Sedan
2009 VUE 3.5L
Default 2009 Vue XE AWD 3.5l transmission feels like engine braking??

I recently had a transmission rebuilt and installed due to the dreaded Wave Plate failure. Now when ever I let off the throttle to coast it feels like engine braking, or letting off throttle and coasting with a manual transmission. it will coast like that with RPMs staying at about 1200-1500 until about 10-15 mph and then you can feel it "release" and come to a stop with RPMs dropping to 800 which is normal with AC on. Here are a couple of thoughts. Is this an issue with Torque convertor not releasing <unlocking>? When they replaced transmission is it possible they pulled the TCM off the old one and put it on without programing or did not program the new one? Its killing my mileage, 12 mpg compared to 16-18 before transmission was replaced and it concerns me that there is something amiss which will only get worse with time. At first I thought is was getting hot as we have had 100+ days here for a week. Transmission fluid is not low or overfull. replaced thermostat in engine and will be putting a cooler and temp gauge on next weekend. Ive been twisting wrenches on my own vehicle and 10 years of racing but this computerized transmission it out of my league. Its under warranty but just looking for information before I take it back this coming Monday.

Any information is appreciated

Ed.
...
And the beat goes on...
EdH is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 07-28-2021, 02:52 PM   #2
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 45,201
 

2003 L-Series 3.0L Sedan
Default Re: 2009 Vue XE AWD 3.5l transmission feels like engine braking??

I've read about wave plate failures being unique to some xmissions. While not familiar with Vues, your the detailed observations after xmission rebuild stands out. Your descriptions of coasting until 15mph may be either a xmission issue or normal. The best thing to do is return to the place that rebuilt your xmission while its still under warranty and describe what you stated here to whoever is knowledgeable of your xmission repair to allow possibly some initial diagnoses based on your recent driving. A road test may help them to understand better to witness what's occurring. When they're driving, they should be able to tell if there's something missed in repairs or the issue is elsewhere.

Most EFI systems have a deceleration fuel cutoff mode from speed. While driving at speed, whenever the gas pedal is released, for those willing to coast instead of standing on the gas pedal then applying brakes without coasting, deceleration fuel cutoff is an emissions program of the EFI system knowing throttle was released at speed and disables injectors, a sophisticated way to use the engine to brake without using brakes to slow the vehicle down from speed. Emission controls would run amok if the engine were allowed to return to idle rpm so a high idle around 1200 rpm is kept while coasting down from speed, not really braking as the high idle allows a gentler slowing down from speed until speed drops to match the high rpm (1200) when the EFI system resumes injector operation and drops throttle to 800 rpm. Everyone driving manuals and coasts in neutral gear sees this on their tach, rpm drops but remains at high idle. Once below 15 mph the high idle drops back to normal idle.

The O2 sensor only outputs signals above 600F and will cool off if exhaust heat doesn't keep it above 600F. Below 600F, the O2 sensor stops outputting and the ecm leaves closed loop mode and enters open loop mode. Open loop mode is usually on cold engine startup where engine coolant is cold, the engine needs a rich mixture and high idle to prevent stalling while the O2 sensor heats up. Once the O2 sensor heats up and the engine is on its way to operating temperatures, idle returns, the emissions system leaves open loop mode and enters closed loop mode for mandated emissions controls of fuel/air mixtures. Closed loop mode with catalytic converters cleans up exhaust byproducts to pollute less. Deceleration fuel cutoff keeps the O2 sensor hot at high idle when releasing throttle for coasting down from speed.

Coasting from speed with EFI systems and emissions controls controls injectors to halt operation while keeping a higher idle until speed drops down below approximately 15 mph. Allow the xmission shop determine whether or not the xmission is at fault or not.

My '77 Datsun 280-Z 5 speed did this fuel injector cutoff whenever I coasted in neutral. EFI systems were already well thought out way back then. Bosch fuel injection is world wide. Catalytic converters took longer to develop. As EFI system were massaged over the decades and catcons are at theor best, we have muscle cars with hundreds of stock horsepower.
fdryer is offline   Reply With Quote
Old 08-01-2021, 09:22 AM   #3
EdH
Junior Member
EdH is on a distinguished road
 
Join Date: Nov 2004
Location: New Jersey
Posts: 29
 

2001 L-Series 2.2L Sedan
2009 VUE 3.5L
Default Re: 2009 Vue XE AWD 3.5l transmission feels like engine braking??

Totally understand now and my mind is somewhat at ease that it is working as advertised. What you replied with was the best and easiest way for me to understand compared to what I found elsewhere. Since I know how the EFI is working correctly, I'll be looking at the O2 sensor, TPF, and MAF sensors, to see if I cant run down why it is running so rich. in other words the EFI only does what the sensors say to do. I'm pulling the plugs today see what they look like and change them. I am scratching my head trying to figure out how to get to the back plugs without pulling half the top of the engine off!! my 2001 L200 2.2 had a flaky MAF sensor and once I replaced it power came back and the it went right back to light tan colored plugs and tailpipe

What ever happened to a 350 Small block, Quadra-Jet and a turbo-350?
Thanks!!
...
And the beat goes on...
EdH is offline   Reply With Quote
Old 08-01-2021, 12:44 PM   #4
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 45,201
 

2003 L-Series 3.0L Sedan
Default Re: 2009 Vue XE AWD 3.5l transmission feels like engine braking??

Unless you logged data on a normal engine to establish baseline values, how are you going to determine which sensors are faulty? Hopefully you have an above average understanding of each sensor and its outputs at various rpm.

After being gifted a moderately priced reader because I wasn't able to determine which reader was suitable, I began to study everyday data then decided to log them. Compiling a file was easy with the capability to transfer data to something like an Excel program to view it on any pc. It then became clear to log baseline data at cold engine, cold warm-up, after warm-up and random speed. The baseline came into use when a member posted issues with his L300 and recorded data (idle rpm). His maf value was in lbs/min, mine in grams/second. Converting values were needed to make comparisons to my values and it was determined his maf sensor was outputting a higher value than normal, faulty. Baseline values are overlooked until a problem occurs. Having baseline values helps when attempting to find faulty sensors. Without it, standard values are needed from trusted sources. Having another vehicle with the same engine can be a source to log normal data.
fdryer is offline   Reply With Quote
Old 08-13-2021, 12:08 PM   #5
EdH
Junior Member
EdH is on a distinguished road
 
Join Date: Nov 2004
Location: New Jersey
Posts: 29
 

2001 L-Series 2.2L Sedan
2009 VUE 3.5L
Default Re: 2009 Vue XE AWD 3.5l transmission feels like engine braking??

Now my brain has exploded I have no access to another vehicle like mine and wouldn't where to start. I guess its going to an ohm meter, alligator clips, and some jumper wires.
...
And the beat goes on...
EdH is offline   Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Transmission feels fun, also trans fluid smell lord_varon Vue Tech 5 04-20-2015 08:53 PM
engine feels disconnected from wheels Burgandy25 Astra Tech 6 01-09-2014 04:51 PM
Engine feels like stalling ilvtofu Astra General 12 04-09-2011 11:57 PM
transmission feels like its siezing corvander Vue Tech 3 02-22-2010 03:01 PM
VTi transmission engine braking dare2be Ion Tech 0 07-07-2008 01:04 AM


All times are GMT -4. The time now is 08:10 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
SaturnFans.com. The Saturn Enthusiasts Site.