Last post on Aug 25, 2012 at 1:58 PM
You are in the Subaru Forester Maintenance & Repair
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Subaru Forester, Engine, Wagon
#211 of 439 Hesitation and Misfires
Feb 24, 2008 (8:42 am)
I've got a used 2002 Subaru Forester with about 57K (only about 3K of which are mine). It ran fine when we bought it, but several weeks later it developed a sporadic problem with engine hesitation and misfires. It's gotten progressively worse since then, and about a week ago the CEL came on for a bit and then went off again.
My mechanic changed the plugs, wires, and air filter (all of which had to be done anyway), but that didn't fix the problem. He also checked the intakes and the fuel pressure, which seems normal, and then he tried a new coil pack. That didn't make a difference either. The reader isn't giving him any codes, except an error message he can't identify, and he thinks the problem is in the main computer. Any thoughts before I take it to the dealer?
#212 of 439 Re: Hesitation and Misfires [ahfisher]
Feb 25, 2008 (8:02 am)
It does sound like your mechanic is checking the right things, in fact I would have done the same thing, in that specific order.
I'm puzzled that he can't read the codes, though?
#213 of 439 Re: Forester revving at stop, etc. Any ideas what it could be? [michaelatsp
Feb 29, 2008 (5:34 pm)
After some more driving I've conclusively seen this happen. I was able to reproduce it a couple of times with the following scenario: driving on a flat road, accelerate away from a stop up into 3rd gear, push in the clutch fully and coast w/o brake. As soon as I push in the clutch, the RPMs drop to 1k and then after a second they slowly rise to ~2k over ~3 seconds. Then it falls back to 1k and the pattern seems to repeat (until I have to brake for the next stop sign).
It doesn't seem to do this at a full stop or on a slight uphill grade and it doesn't happen every time regardless. Today the engine was pretty cool: ~60F out + ~10min drive + ~20min park + ~5min drive.
It must the computer telling the throttle to do something -- keep the catalytic hot?
#214 of 439 Re: Forester revving at stop, etc. Any ideas what it could be? [michaelatsp [johnv]
Mar 01, 2008 (6:52 am)
The only time the engine should be idling fast is when it's still cold (or thinks it is). Where's the needle on the temp gauge when this happens?
As long as the clutch is fully depressed, it doesn't matter whether you're completely stopped or coasting at 80 mph, the engine should be at idle speed (750 rpm).
#215 of 439 Re: Forester revving at stop, etc. Any ideas what it could be? [michaelatsp
Mar 15, 2008 (10:02 pm)
I have the exact problem with a 98 Forester S AT with 102k miles. I took my car to the dealer the first time the CEL came on and they diagnosed the problem as Cyl 1 misfire and replaced the spark plugs. The car was fine for a few days and then the problem came back at a stop light. I am able to easily replicate the problem by getting the engine warm and then stopping - like you would at a stop light. The hesitation is so bad that the car shakes.
I have seen in other forums that the problem is with the ECM. Did any of you experiencing these problems arrive at the same conclusion? I would appreciate an update if anyone has found a resolution to this - will save me more costly dealership visits.
#216 of 439 Re: Forester revving at stop, etc. Any ideas what it could be? [michaelatsp [frstr08]
Mar 17, 2008 (7:31 am)
If you've only done the plugs so far, I would change the plug wires, too, which are usually a 60k miles item, and then the ignition coil (about $80 at a wholesaler).
Either of those could be causing the misfire.
#217 of 439 Re: Forester revving at stop, etc. Any ideas what it could be? [ateixeira]
Mar 17, 2008 (9:00 am)
I took the Car to Autozone yesterday to scan codes and got the same code as before P0301. Also this morning as I was driving in stop and go traffic, I got the same hesitation and the CEL came on. I will take the car back to dealer this week and have the above items replaced.
#218 of 439 Greetings Old Friends
Apr 08, 2008 (12:15 pm)
Well, I've been away a long, long while, but life is good with us. We still own the 01 Forester S+ that brought us to these fine forums, and replaced our 03 MPV with an 05 Outback XT last fall.
Pleased to see so many old posters still haunting these parts: subearu, juice, paisan and the rest.
I trust the recent past has been good to all of you.
In addition to wanting to reconnect, we unfortunately have need for your advice. The Forester has developed a CEL that appears to be related to outside temperature. Drive more than a few miles with the outside temps below 40 or so, and the light comes on. A few days above 45 and it goes out again.
I had the code pulled, and it was a P0128 - "Engine coolant temperature sensor out of range low."
The dashboard engine temp gauge does indeed look to run a little on the low side, but it's hard to tell.
What does that sound like to you guys? Thermostat? I'm told those "never go out".
We had a fender bender last summer, so that everything from the fan belts forward is new. We're coming up on 8 years of ownership, and have enjoyed 78k otherwise trouble-free miles.
Thanks in advance,
#219 of 439 Re: Greetings Old Friends [bsvoller]
Apr 08, 2008 (7:13 pm)
Sounds like the Coolant Temp Sensor is bad. That's not the T-stat, it's an electronic sensor that tells the ECU what temp the car is running at so it can compensate for it with the fuel mixture.
#220 of 439 2006 Forester Engine Seized
Apr 26, 2008 (6:51 pm)
My 2006 Forester stopped a week ago. After it was towed to Subaru I was informed that the reason the engine clanged to a stop is that there was carbon buildup in the engine. While I do have 67,000 miles on this less than 3 year old car I have also had four other Subs and have never had a major problem. Sommechanics I have talked to said this "carbon" explanation sounds bogus. Any suggestions on the issue and also how to deal with Subaru?