SaabCentral Forums banner
1 - 17 of 17 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hello all,

I recently became the excited new owner of a sleek 2008 Saab 9-5 in Titan Grey, an amazing upgrade from the 2004 9-5 Linear I was sporting before. Unfortunately, taking ownership of this car has caused me to join the "9-5 slow acceleration/low boost" club. Here's the issue:

The A/C compressor bearing was beginning to fail when I bought the car. Originally, I believed that this was placing extra load on the engine and causing slow acceleration as it felt like the engine was fighting this load before delivering power to the wheels (especially when going up hills). Although performance and acceleration did improve after replacing the compressor, it still feels nothing like the 2006 9-5 Aero owned by a family member. Replacing all vacuum lines with silicon, as well as cleaning the MAF/BPC thoroughly has made no improvements. Adding the “bolt mod” has helped with responsiveness and acceleration right off the line, but once up to speed, the Saab feels more like a Camry. Although the turbo gauge does go into the lower red region during “spirited drives,” there is a definite lack of boost and no saab “punch.” I always run the car on 93 octane and within the past year many parts have been replaced such as the: Mann air filter, throttle body, spark plugs, DIC, BPV, thermostat and crankshaft position sensor.

Any help with this problem would be greatly appreciated! I have a generic OBD scanner if any parameters are needed.

Cheers.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #4 ·
I have not yet checked for boost leaks, however I'll have to look into putting together a system like that.

The DIC is about a year old and I have an extra one in the trunk that I tried out with no change.
 

·
Registered
Joined
·
1,826 Posts
Are the DICs real? I.e. SEM? Aftermarket substitutes have a certain reputation. I’ve heard they might be fine until you make demands on them then they falter.

Isn’t the bolt mod in effect incorporated into the 2006 and after 9-5s? I thought it was all about bypassing an evap valve failure, and the valve is deleted from the later cars.

Happy to be corrected of course.

Doug
 

·
Registered
SAABless booo
Joined
·
2,523 Posts
Do you get a screeching/shrieking sound at full throttle?
If so, it could be a very small vacuum leak, or in the case of my car, a Catalytic converter starting to get fully blocked/plugged.
 

·
Registered
Joined
·
1,258 Posts
Do you get a screeching/shrieking sound at full throttle?
If so, it could be a very small vacuum leak, or in the case of my car, a Catalytic converter starting to get fully blocked/plugged.
Did you have flashing cell before you have been found your CC issue ?
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #11 ·
Apologies for the hiatus! Dropping temperatures up here in the north has got everyone bracing for winter ahead.

The DIC in the trunk is a Proparts cassette, I am aware of their reputation and bought it strictly in the event of an emergency, it is brand-new, however. The P/O installed the current DIC so I am unfortunately not aware of the make. Seeing as most parts he had installed are Genuine Saab, I'm leaning toward the DIC being genuine as well.

The car isn't making any odd noises at full throttle, just the sweet roar of the 2.3! I suppose it can't hurt to drop the CC from the turbo and see if there is any blockage as the car does have 140k miles under its belt.

Thank you for the information regarding the bolt mod! Most forums I read omitted that detail, but after comparing schematics you are absolutely right, thankfully it is easy to undo. I'm going to make an appointment with an independent shop around here that has a smoke machine. Just want to rule leaks out of the equation! I will make sure to have them check out the intercooler lines as well.

Thank you again for all of your help.
 

·
Registered
SAABless booo
Joined
·
2,523 Posts
The car isn't making any odd noises at full throttle, just the sweet roar of the 2.3! I suppose it can't hurt to drop the CC from the turbo and see if there is any blockage as the car does have 140k miles under its belt.
You don't need to drop the CC. Just unscrew the front most 02 sensor to give exhaust somewhere to escape. Test the acceleration. If it's a rocket again, then you know you have blockage somewhere within the CC/exhaust system.
If there is no real change with the 02 sensor unscrewed, then you can rule that out.
Now, just to be clear, I mean, actually unscrewing the 02 sensor and removing it so there's an open hole. Disconnecting the electrical connection and leaving the sensor screwed in will do nothing to check for exhaust blockage.
 

·
Registered
Joined
·
10,873 Posts
It's only four screws and one connector with the sliding red locking tab and you can see what brand the car's present DIC is.


I would trust a junkyard car DIC, as long as it has a date code within the last ten years, over a new ProParts DIC.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #15 ·
I pulled the DIC off the other day and found it to in fact be a Genuine Saab part with a recent date of manufacture and in good condition. A local indy shop here in Pennsylvania (where I go to school) will be testing the vacuum system with a smoke machine this Thursday, do you guys recommend any other areas they should check out?

Also, I whipped out the ol' OBDII reader today and did some data logging which returned interesting results:

At idle, short fuel trim is maxed out at 25%

load percentage is ~22%,

MAP 5.5 psi,

ignition timing hovers between 7/8 with occasional spikes to 11,

both o2 sensors read 0.55-0.60 (they fluctuate in unison)

Could I be looking at a bad O2 sensor as well?
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top