Northern1 Posted December 4, 2019 Share Posted December 4, 2019 Under a steady constant throttle the car appears to slightly intermittently surge. I can feel it pull then recede over and over, though suttle. Seems to happen or is most noticeable in the lower RPMs. I would think that it might be the MAF sensor (which was actually replaced by previous owner a couple years ago) or something with the air/fuel mixture being off but I don't see the RPMs jumping around while under constant throttle. I did notice today that there was an engine surge and RPM blip while idling in neutral though. That may be normal, I don't know. Part of me is wondering if it's the drivetrain. Don't know if this is related or a separate issue but on cold start the car idles very rough for about a minute, like the car shakes, then it smoothes out. Maybe a misfire? The car runs really rich upon cold start. I also noticed an intermittent click sound from the engine bay at times which I think is tied to to when the car is warming up and the RPMS float up and then rest and then goes up and then rests lower till finally the car idles smooth at like 750 RPM. Link to comment Share on other sites More sharing options...
HiiiFiii Posted December 4, 2019 Share Posted December 4, 2019 Sounds like it could be the MAF. Have you checked to see if the sensor is dirty? Sometimes (rarely) cleaning the sensor will at least improve the surging/idle problem. Also, does this "clicking" sound sound a bit like a rod knock? If so and if it does actually go away after warm up figure that to just be a normal Subaru thing. I had a similar "surge" issue with my 98 Outback. Meaning that the surge was more like a flat spot in acceleration under load. It would often go away after warm up but was definitely prevalent between 2000-3500 rpm. I replaced just about everything (coil, plugs, wires, MAF, PCV, engine grounds, battery and coolant temp sensor) but it still persisted. After a bit more research I found that it could be the ECU that causes this. I bit the bullet and got a replacement - note you'll need to get the vin programmed into the replacement. Replacing the ECU fixed the "surging" for me. The ECU and programming ran me $450. Link to comment Share on other sites More sharing options...
Northern1 Posted December 4, 2019 Author Share Posted December 4, 2019 Hey thanks. I guess I'll have a mechanic look at the MAF and I suppose with that spark plugs and other related fuel/air components. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now