S80 - rough idle and no power under load
Hey everyone, hoping you can help me out. I have a 2001 s80 2.9l with 140k miles. A week ago I experienced an immediate loss of power. I was close enough to home that I got the car back, and I’ve been trouble shooting since.
Right now I can get the car to idle on startup, if I give it gas. If I don’t it cranks to 2400rpms or so and immediately stalls. If I give it gas, like 3/4 throttle, it’ll catch and idle - sometimes rough and sometimes smooth. It revs smoothly up to 2400rpms or so, but won’t go above that, even under WOT. I can drive it, kind of. It’ll shift into gear and move, but it will not go above 1400 rpms or so under load, basically as if it’s idling. Doesn’t matter if the pedal is mashed to the floor or barely pressed.
So here’s the kicker - it’s not throwing a single code. Not for me on my scan tool and not for autozone (close enough I could limp it there).
Here’s what I’ve done so far:
-cleaned the etm (idle smoother but no change in power under load)
-replaced the maf (no change)
-replaced the plugs
-replaced the fuel pump
Tomorrow I’m testing the cats (to see if they’re plugged) and rechecking the plugs (to see if a coil or 6 is bad) but both seem like deadends since I’m throwing no codes.
Any ideas?
Right now I can get the car to idle on startup, if I give it gas. If I don’t it cranks to 2400rpms or so and immediately stalls. If I give it gas, like 3/4 throttle, it’ll catch and idle - sometimes rough and sometimes smooth. It revs smoothly up to 2400rpms or so, but won’t go above that, even under WOT. I can drive it, kind of. It’ll shift into gear and move, but it will not go above 1400 rpms or so under load, basically as if it’s idling. Doesn’t matter if the pedal is mashed to the floor or barely pressed.
So here’s the kicker - it’s not throwing a single code. Not for me on my scan tool and not for autozone (close enough I could limp it there).
Here’s what I’ve done so far:
-cleaned the etm (idle smoother but no change in power under load)
-replaced the maf (no change)
-replaced the plugs
-replaced the fuel pump
Tomorrow I’m testing the cats (to see if they’re plugged) and rechecking the plugs (to see if a coil or 6 is bad) but both seem like deadends since I’m throwing no codes.
Any ideas?
I would use an OBD reader on it that can scan the operating parameters and check values of O2 sensors and fuel trims to see if that reveals anything before changing any other components.
This video will show you how an expert electrical diagnosis can help
He has some volvo videos but not quite what you have experienced.
This video will show you how an expert electrical diagnosis can help
Hi,
I am in a similar situation with the exact same model with no codes in the scanner. Did cleaning the Catalytic conv. or any solution help.
Coincidentally I did similar things too:
- cleaned the etm
- cleaned the maf (no change)
- replaced the plugs
- replaced the PCV system mostly and cleaned the intakes.
I am thinking of checking the Catalytic conv. but nice to get some direction here and is appreciated.
--
Thanks.
I am in a similar situation with the exact same model with no codes in the scanner. Did cleaning the Catalytic conv. or any solution help.
Coincidentally I did similar things too:
- cleaned the etm
- cleaned the maf (no change)
- replaced the plugs
- replaced the PCV system mostly and cleaned the intakes.
I am thinking of checking the Catalytic conv. but nice to get some direction here and is appreciated.
--
Thanks.
Quick test is disconnect the exhaust ahead of the cat and see what you get.
Last edited by erfint4; Feb 20, 2026 at 11:57 AM.
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