2010 forester sluggish going uphill

[dogg]

I recently got a (local) used 2010 non-turbo automatic forester and its fine except it struggles to go uphill and build up faster speeds. I have to manually put it into lower gears to get it going at a reasonable speed uphill, but even then its not quite as responsive as i think it should be. My wife's older Rav4 zooms over hills and accelerates like its nobody's business. The Forester struggles way too much by comparison.

Acceleration from 0-80km on the highway is smooth and fast, but it hesitates to go from 80- 120km ph. And even then it feels like its straining. I've rarely ever gotten it to go over 130km.

I've taken it to a few mechanics (including two Subaru specialists) and they all say its working fine. But I don't think it should be struggling as it seems to be.

One mechanic changed the knock sensor and that seemed to have helped, but just a little.
Another cleaned the fuel injectors, but that didn't do anything.

I don't know much about cars, any advice would be appreciated.

[zondafan]

Probably best to get the car scanned by someone who knows what they doing.
You can end up changing a lot of parts and never fix the problem.

[antlind]

Interesting problem. I did a quick search and found similar comments for the NA engines. Some posters said it could be a plugged cat converter or a gummed up valve.
Either way, do some digging in the Subaru online forums to identify potential causes before you spend a ton of money fixing non-problem areas.
Good luck.

[racedriverpro]

Interesting problem. I did a quick search and found similar comments for the NA engines. Some posters said it could be a plugged cat converter or a gummed up valve.
Either way, do some digging in the Subaru online forums to identify potential causes before you spend a ton of money fixing non-problem areas.
Good luck.

Yup. Good advice here...the cat being plugged is highly possible and should be relatively easy and cheap to check.

Sent from my C6603 using Tapatalk

[BRZ]

Had a problem like that once with another brand of vehicle, turned out that the vehicle when it came from Eurpoe was not geared to handle climbing inclines and the vehicle always struggled uphill or nerer made it ,once the company changed the gearing for the correct application, it was so much better.

[tr1ad]

Clean the cat.... Or remove it entirely

[supercharged turbo]

Check a reputable muffler shop and let them do an assessment.What area you from?

[dogg]

I'm in San Juan. What exactly would the muffler shop be looking for?

Check a reputable muffler shop and let them do an assessment.What area you from?

[dogg]

This is some advice I got on a mechanic message board:

disconnect battery for 10 minutes and reconnect, if this solves the sluggish problem then clean the mass air flow sensor, and check or replace the O2 sensors.

Is that a viable option?

[antlind]

This is some advice I got on a mechanic message board:

disconnect battery for 10 minutes and reconnect, if this solves the sluggish problem then clean the mass air flow sensor, and check or replace the O2 sensors.

Is that a viable option?

If those sensors were failing it might have triggered a check engine light already.
Cleaning them involves taking them out and spraying them with brake cleaner. It's not an easy task if you're not mechanically inclined.

[racedriverpro]

Head gasket ruled out?

Sent from my C6603 using Tapatalk

[supercharged turbo]

I'm in San Juan. What exactly would the muffler shop be looking for?

Check a reputable muffler shop and let them do an assessment.What area you from?

They suppose to tell you if the cat is clogged and either condemn it and run a straight pipe or if to replace the cat.Know someone who had the same problem with a A33.The problem was persistent in any terrain and was solved by replacing the cat.

[Groovemaster]

When you press the accelerator to go faster ...... does it feel like the gear don't drop and it's trying to climb the hill in third gear?

Why I ask I have the same problem (Mazda 323). I tried coilpacks, change tranny oil and strainer, engine oil, TB service and clean.....I don't know what again it could have been until I read this post..

[dogg]

When you press the accelerator to go faster ...... does it feel like the gear don't drop and it's trying to climb the hill in third gear?

Yep, thats exactly how it feels

[boosted_wrx]

NA subarus be it 1.6 or even 2.0 have low torque outputs at low speeds, it's a common problem, but if it's so bad to struggle up hill do a complete service, swap plugs and change oil and air filter and once a month mix 10-15 dollars in kerosene in the tank when you full up helps get rid of any extra build up on the valves

[dogg]

I did a full service at Massy, also changed ALL fluids, there wasn't a noticeable difference in the performance issue. How safe is pouring kerosene in the gas tank? wouldn't that cause other problems?

NA subarus be it 1.6 or even 2.0 have low torque outputs at low speeds, it's a common problem, but if it's so bad to struggle up hill do a complete service, swap plugs and change oil and air filter and once a month mix 10-15 dollars in kerosene in the tank when you full up helps get rid of any extra build up on the valves

[boosted_wrx]

Actually did it to my 1.5l EL15, it helped clean the injectors and I got some special Liqu-moly treatment and it improved the performance, loosed up all the guck in the valve train, it's safe but don't run straight kerosene just a little

[dogg]

what treatment was it?