over boosting?
Discussion
my saab is sick.. 
scenario, entering on the motorway 3rd gear 35mph behind a lorry, pull out to over take foot down full boost etc then all of a sudden half way through the rev range boost drops away and i'm left with a semi boosting turbo. the turbo isn't providing much power at all, the whole car felt flat. while until i could pull over and switch off. i get a chance to switch off and and let the car cool down. switch engine on, check 'ok', and the car drives normally.. except the turbo needle swings way into the red zone not the usual 2nd marker on red zone. the engine is 'fluttering' under WOT when the needle is fully extended ont hr last red marker.
the car feels little fast as well
whats wrong with my car?! wastegate broken? i'm gonna call the dealer tomorrow and get them to check it out.
cheers
NST
Edit:
just to add this morning the car the boosting as expected in 4th/5th and 6th gear 2nd and 3rd gear not getting full boost.
scenario, entering on the motorway 3rd gear 35mph behind a lorry, pull out to over take foot down full boost etc then all of a sudden half way through the rev range boost drops away and i'm left with a semi boosting turbo. the turbo isn't providing much power at all, the whole car felt flat. while until i could pull over and switch off. i get a chance to switch off and and let the car cool down. switch engine on, check 'ok', and the car drives normally.. except the turbo needle swings way into the red zone not the usual 2nd marker on red zone. the engine is 'fluttering' under WOT when the needle is fully extended ont hr last red marker.
the car feels little fast as well
whats wrong with my car?! wastegate broken? i'm gonna call the dealer tomorrow and get them to check it out.
cheers
NST
Edit:
just to add this morning the car the boosting as expected in 4th/5th and 6th gear 2nd and 3rd gear not getting full boost.
Edited by NST on Wednesday 1st April 10:31
Hi,
the dealership had it yesterday all day to check it over, (excellent service from the dealership).
no fault codes or anything, but as a precaution dealership contacted Hirsch to query them about any issues with possible issues with the map. Dealership reapplied the Hirsch map and so far no problems. infact i would say the car 'feels' little slower/less aggressive, but on a positive note the engine feels smoother through the rev range. MPG seems to have improved as well.
on a more worrying note, i had a rear suspension arm replaced(bushes?), CV boot was leaking (new clip and grease) and something about the steering arms replaced under warranty. none of these are expensive items but are common according to the dealership.
car is running well again.
cheers
NST
the dealership had it yesterday all day to check it over, (excellent service from the dealership).
no fault codes or anything, but as a precaution dealership contacted Hirsch to query them about any issues with possible issues with the map. Dealership reapplied the Hirsch map and so far no problems. infact i would say the car 'feels' little slower/less aggressive, but on a positive note the engine feels smoother through the rev range. MPG seems to have improved as well.
on a more worrying note, i had a rear suspension arm replaced(bushes?), CV boot was leaking (new clip and grease) and something about the steering arms replaced under warranty. none of these are expensive items but are common according to the dealership.
car is running well again.
cheers
NST
Edited by NST on Friday 3rd April 08:27
NiceCupOfTea said:
Hmmm, strange - on a more "analogue" car I would put it down to experience and a bit of boost being pulled back due to knock, but on a digital T7(?) system I would assume all of this stuff is much more tightly controlled...
Worth asking on SaabCentral?
T7? not sure what that is? ECU? i think it has the Bosch ECU.Worth asking on SaabCentral?
i'll try and get my self registered with Saab central, seems like a very lively forum.
cheers
NST
T7 stands for Trionic 7 - Trionic is Saab's engine management system, controlling boost / ignition / fuelling / pretty much everything else. It was well ahead of its time in the early 90s when it came out and has been developed consistently since. Also highly programmable - T5 is being retrofitted to many c900s now.
http://en.wikipedia.org/wiki/Trionic
I think your car will have T7.
http://en.wikipedia.org/wiki/Trionic
I think your car will have T7.
NiceCupOfTea said:
NST said:
i found this from googling
here
Oops, sorry, didn't realise you had a V6 turbo - don't know much about these new-fangled cars here
Might be worth asking if there are any known issues with the Bosch ECU on the V6T cars?my local dealer has had a few V6 aeros in and this was a new problem he hasn't seen before. the most common problem being the coolant header tank.
very robust engine was his comment.
A mate of mine drives a v6turbo vectra (same engine) for his work, has had the same problem on more than one occasion went to vaux dealer put on diagnostic machine fault code overboosting, cleared code was fine for a day then fault came back into dealer same process again was ok for a week or so managment light came on back in again this time the turbo was replaced (twin scroll turbo) and ecu was changed it's been fine since (this happened 6months ago)
hope this helps
hope this helps
NST said:
Thanks for the reply, The dealer is going to replace the boost control valve next week, which i hope will sort the problem.
I get the feeling this isn;t going to sort the problem in the long term.
It might do, overboosting is usually the sign of a fautly BPCV on the Trionic ECU 4 cyl Saab turbos (had this on 2 x previous Saabs) so maybe the case with the Bosch controlled V6T as well.I get the feeling this isn;t going to sort the problem in the long term.
underated cars those 9-3sNST said:
I think the problem is fixed! no more boost issues. on a positive note the engine now revs right round to the cut out without the usual drop of in power in the last 1Krpm! it really shifts now!
Good news sir!!!!!!!!!!my mates Vectra 2.8t was the same after it was finally fixed Note:he reckons the vectra is now about 300hp+ serious mid range clout enjoyGassing Station | Saab | Top of Page | What's New | My Stuff