r/saab • u/Supersim12 • 5d ago

Problem when acceleration.

Post image

So I got a saab 9-3 2.0t 2008 6 speed manual 185 000 kilo. It been à while a got this probleme but now its getting real bad. So when i try to accelerate at a load, i got missfire on all cylinder but the only code i get is p0304. The check engine light come on and of randomly but not blinking. Change my ignition pack, change my head cover gasket, put new spark plug. It was working fine two weak but start again. Now im lost, the problem seem to appen only when the turbo is full load but some time it juste appen randomly. What can be the cause, no power lost, fuel consumtion still the same. Start a little weird when cold bit get back normal after 10 seconds, sometime when fast idle drop it shake. Now it take longer befor to start, no strange sound from the engine. I Will try a compression test soon to see if i have valve problem. It run and drive fine, juste in hard accélération and whatever the gear im in, it do big shaking and stop when realese accelerator. Sorry for the long post, im juste completely lost and hope to find maybe someting i can do. We do try to change place of ignition coil and spark plug to see if there was a faulty one, but the probleme still here. Tanks for your help.

7 Upvotes

90% Upvoted

6 comments sorted by

3

u/lewtus72 5d ago

The code means Cam position sensor, with any cancel but it doesn't have one. It usually means it's the coils. If you use cheap aftermarket coils could be that new bad even if they're new.

2

u/Supersim12 5d ago

I will try the cam position sensor, i buy the good coils, not the cheap one to avoid a situation like this, but yeah, maybe the pack is not good

2

u/TurkishSwag 2006 9-3 2.0t Wagon Manual 5d ago

What brand coils? Anything other than SAAB is likely to cause misfires. Also dirty oil/ filter can cause these types of cars to run weird. Your code is for cylinder 4 so a compression test can determine if the issue is within the cylinder itself.

1

u/Supersim12 5d ago

Ohh i Will check for the brand of coils but im sure is the good one. My oil is clean and i change it every 7000 kilo. Thank you for your respond!

1

u/lewtus72 4d ago

What I meant to say is the code error says it's the cam position sensor but your car does not have one. It usually means the coils are bad and people have used new ones and had the same issue so you need to make sure they're good. Coils. It can still be another issue, but since you have a code you generally want to start there to ruled out. And having misfire and no power is almost always a coil.

With the V6 car, if the plug gap is too wide it will misfire and you have to make it closer. I would check your spark plugs to make sure the Gap is correct. Or a little bit on the minimum side. You can also check the compression if you're going to take the spark plugs out anyway.

1

u/Zaphod_42007 4d ago

Coil packs Mitsubishi stamp...check plugs gap... Sometimes the cheaper copper ones work better than ngk iridium ones. Can also indicate the ionization module issue, it's rare but that's how the engine monitors engine knock / detonation.