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Hello All,

I have a 2008 Saab 9-5 with about 98k miles on it. Bought it about a year ago. Very nice car, runs very well.

About 2 weeks ago I noticed the car was sluggish. No pick up, no go. But other than that once it was up to speed it seems to run good.

Checking the turbo gauge I noticed it wasn't moving into the turbo section of the gauge. That was my ahhh moment as to why the car seemed so sluggish.

No smoke, nothing leaking. Does not appear to have any hoses disconnected. Nothing on the display. Waste gate lever is in correct position.

Does anyone have an idea as to why the turbo isn't working? Any help would be greatly appreciated.
 

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That "Turbo" gauge is not a boost gauge but a "load" gauge. While the turbo could be the cause I would start by checking all the CAC hoses for leaks as well as all the vac lines on the engine. Make sure the intake tubes around the MAF are tight, the MAF is clean and be sure the air filter isn't old and full of garbage. This would be my starting point. If you still suspect the turbo you can pull the exhaust off and spin the turbine wheel and check for play.
 

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I will put in a new air filter to see what happens. First inspection all hoses appear to be okay, intake tubes to be okay as well. Will double check. Will let you know what happens. Thx.
 

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I'm not sure exactly what it is measuring on these cars but typically load is a complex equation taking into account the MAF, fuel delivery, MAP pressure, AP position and maybe even some trans info if it's an automatic. So it wouldn't be a sensor output but the PCM outputting the signal to the cluster based on whatever algorithm is programmed. Load % is usually a PID you can look at on most cars with a manufacture specific scan tool, just that it's usually never displayed on a cluster for a customer to see. Labeling it "Turbo" gives you the impression it is a boost gauge although I'm sure there is a pretty close correlation to high load = high boost.
 

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I'm not sure exactly what it is measuring on these cars but typically load is a complex equation taking into account the MAF, fuel delivery, MAP pressure, AP position and maybe even some trans info if it's an automatic. So it wouldn't be a sensor output but the PCM outputting the signal to the cluster based on whatever algorithm is programmed. Load % is usually a PID you can look at on most cars with a manufacture specific scan tool, just that it's usually never displayed on a cluster for a customer to see. Labeling it "Turbo" gives you the impression it is a boost gauge although I'm sure there is a pretty close correlation to high load = high boost.
MAP pressure must be fairly closely associated with "Boost."

So the answer is multiple ECU inputs from various sensors plus algorithm.
 

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From the WIS (MIU, Turbo Boost Gauge section of the description):

"The value shown by the boost gauge needle is based on the following: Trionic calculates the mg air mass/combustion and converts is to a value between 0 and 255. Trionic sends this as a bus message "boost gauge". This value corresponds quite well to the engine torque."
 

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From the WIS (MIU, Turbo Boost Gauge section of the description):

"The value shown by the boost gauge needle is based on the following: Trionic calculates the mg air mass/combustion and converts is to a value between 0 and 255. Trionic sends this as a bus message "boost gauge". This value corresponds quite well to the engine torque."
Thank you.
 

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Do you know anyone that does work on Saab. I'm in london ontario
Southwestern Ontario lost Saab of London and Saab of K-W. I'm not sure who might specialize in Saabs west of Oakville. The GTA still has several shops.

Ultimately, Saab owners will need to be able to either do the job themselves, or know enough about the job (through reading WIS--Workshop Information System) to be able to guide a competent mechanic through a job.
 
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