SaabCentral Forums banner

1 - 5 of 5 Posts

·
Registered
SAAB 95 2004 Linear Wagon
Joined
·
140 Posts
Discussion Starter #1 (Edited)
2004 linear 95, auto transmission 5 speed, 110.000 km ( = 70k miles)

i have had this happen 3 or 4 times in the last couple of months, and when it occurred earlier today it was the most disturbing event so far
summary of observations:
  • this first event might be unrelated ? i was driving for 10 min on the freeway 2 or 3 months ago @ 100 km/hr ( i assume with the auto trans in 5th ) , it suddenly felt as if the car upshifted to another gear and was accelerating a little (but there is no 6 th gear and i had not altered my pressure on the accelerator). it was so noticeable i had to lift my foot partially off the accelerator to stay at my 100 km/hr speed limit. the car drove well however, no other signs of errors or strange noises. a few km later i was at my exit and near home, and on the last few local streets the car behaved normally, i forget about it in the next days , and for several weeks no other similar issue. this might be unrelated to the next events, but could be related since it involves acceleration (but i wasnt watching the rev counter this time)
  • 4 weeks ago i am gently reversing out of a car park spot in a large carpark, and suddenly the engine revs approx 700 - 1000 revs higher causing the car to want to accelerate.. because it is an auto transmission , while reversing, i had just been gently "riding the brake" and didnt have my foot on the accelerator. by pressing harder on the brake i was able to keep the car stationary , but it was a bit unnerving (and could have been dangerous). after 30 - 90 sec the revs returned to normal as i was exiting the car park
  • 2 weeks ago, again driving out of a local shopping center car park (forward this time) , the car suddenly increased its revs by approx 700 - 800 revs and wanted to suddenly, again accelerate. firmly applying the brake secured the car . it then settled back to normal in 20 or 30 sec and was ok again.
  • today again a similar occurrence, but this time i was idling in "D" (drive) at a traffic light when the engine suddenly rev'ed 800 to 1000 rpm and wanted to accelerate (i saw the rev counter indicator). this event felt a little stronger then before, and i moved the shifter to neutral, which seemed to return the revs to normal (or was a coincindence ?). it also almost felt briefly like the engine would stall out, but as the revs were reducing i put it back in D and drove away (light had changed). drove fine for the rest of the small distance home
note: summer is starting here, so weather is getting warmer in the last weeks. also each of these 3 or 4 times this happend in the last couple of months, the car had been driven locally , then was stationary for 20 or 30 min (local shops for ex) , and the odd acceleration symptom occurred each time AFTER i had restarted the car to drive back home etc (eg engine and gearbox would have been warm/hot).

maintenance: i did change the auto trans oil 4 yrs ago, but not since then (but doing normal annual engine oil changes and servicing etc)
  • recently replaced alternator and voltage regulator 4 months ago (so dismantled several bits including lower rear engine mount, maybe i disturbed something ?)
  • turbo started smoking on AM start in the last few months, will need to replace LP turbo soon but trying to delay it for now. current iddle issue related somehow ? (unlikely i suspect)
any suggestions what could cause this ?

i hope it is not an internal gearbox problem. could be an electronic control element relating to the gearbox ? (not sure if there is one even), maybe something to do with the throttle body ? lastly, maybe an ECU issue with the T7 trionic
 

·
Registered
Joined
·
2,395 Posts
Agree with thaistatos - sounds like a throttle body issue. I don't think it sounds like a transmission thing. I am assuming that you don't have any check engine light illuminated?
 

·
Registered
Joined
·
8,869 Posts
Have you checked engine oil level? Has it dropped?
Vacuum lines?
 

·
Registered
Joined
·
90 Posts
Throttle body definitely possible, also check for intake leak. This causes a lean condition and results in higher revs at idle - would be a bit erratic also. I'd check all your intake joints and while you're over at the throttle body I'd check the butterfly valve to make sure it's smooth when you rotate it and its motion is not obstructed. Just thoughts.
 
1 - 5 of 5 Posts
Top