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Subaru Forester Car Problems

Engine Misfire Due to Failed Spark Plug Wires on Subaru Forester

Problem Description and Solution

Sometimes the Check Engine Light illuminates because the computer detects misfires. Subaru released an improved spark plug wire set to solve the problem. The ignition coil should also be inspected for carbon tracks or short circuits between the contacts

(63 people reported this problem)

Problem Data

RepairPal Fair Price Estimate
$291-834
RepairPal Verified
Average mileage: 94,405 (40,869–205,183)
Engines affected: 2.5L 4 Cylinder, 2.5L 4 Cylinder Turbo
14 model years affected: 1998, 2000, 2001, 2002, more2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2014

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Brake problem? Or maybe a faulty head gasket cylinder?
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Viewing 1-20 of 27 comments
Engine started to stutter at idle last night. After 5 min, it was fine and running perfectly. Next day, ran perfectly for 15 min, then started to stutter when idling. Check engine light and cruise control light are on now. Never had a problem with this car before.
Drove home after a 100 mile trip around some twisty fun roads. Woke up the next day with the car throwing three codes. 02 sensor/Evap/Misfire cylinder 3. Just bought the car! What are the odds.
No engine lights came on, but engine turned off at stop signs several times in the last week. The repair shop diagnosis is wires, oil change, spark plugs. It seems that if this is a common problem, it should be considered under the Lemon Law or covered under the warranty.
After starting he vehicle and going down the road {I have standard transmission} the car starts stalling and engine light starts blinking;
resolves itself after about 1/2 a mile; but only after a hard rain does this happen.
The check engine light came on and then the cruise control light. Next thing I know my Forrester is shaking left and right. The codes said missfire in cylinders 3 and 4, so I changed the spark plugs. The problem started back up 2 days later and I ended up have to replace the coil.
I installed a new set of Belden plug wires from NAPA. The issue came back. I completely removed the wires and the ignition pack to inspect it, reconnected everything, and the CEL went away. So all is well!
The check engine light illuminated and another dash light blinked continuously. I took it in to my mechanic, who said the wires and seals had to be replaced ($380). My friend had the same lights go off less than a week later and the Subaru dealer told her it was the catalytic converter.
Same as others stalled a few times, then ran fine. Today stalled repeatedly with check engine light on, cruise light flashing and slippery pavement light on. Diagnosed as cracked coil, fried spark plug wires and need to replace spark plugs.
Check engine light flashing, then going off. Eventually CEL stayed on. Diagnosed bad plug wires. They were just changed 1 year ago at 30,000 miles too. We'll see if thats the end of it.
Misfire on Cylinder 2 & 4. Replace Spark plug wires but still misfire code. Replace engine coil and misfire code went away.
Check engine light indicated misfire on #2 cylinder. Found spark plug wire was arching at/near coil. Replaced all plugs, wires and coil. Then same check engine light 2 months later indicating misfire on #2. This time found hole burnt through plug wire housing boot over actual spark plug which was arching onto manifold! Original problem occurred with original equipment wires and FR5AP-11 (NGK) spark plugs. Second incident happened after new coil, plugs and wires using OEM recommended NGK (55004) FX101 Spark Plug Wire Set and NGK (5464) IX Iridium Spark Plug
8-9 hours into road trip check engine light came on. Dealership said to change spark plugs due to misfire. Did so. Next car trip same thing . About 3 weeks after plugs replaced. They mentioned ignition coil but tried to get check engine light to go off and couldn't . They Made a note in file. Told me when it goes off to not turn off car and drive straight to dealership ...but chances are they will be closed .
Consistent misfire on the cylinder 3. Replacing the coil helped for a while, then check engine light would go off, especially after wet weather. The last time the misfire was terrible, replacing wires and plugs helped. there was no need to replace the coil.
month ago, check engine and cruise lights on. subaru rec check gas cap. took it off and put back on. prob persisted.
3 days later, subaru svc could find no prob even tho the check eng came back as misfire. yesterday, car was dif to start and when put in gear, stalled. did not start after that. towed to subaru. result, ignition coil towers cracked and ignition wires burnt at coil. replaced. works fine.
About 5 k after the 60k service I had misfire/omission problems. My local mechanic at first said it was a spark plug wire, the car shook like a monster was shaking it. Then it kept happening and he replace more spark plugs. After the third attempt he was frustrated and upset, ( not any more than I was!) and said it was the sensors. But wait! After leaving my car all day at his shop, he said it now was the coil, which he replace at a significant cost. It ran fine for about three weeks, and the same thing is happening again.!!!!!!!!!! I've had two other Subaru's that I put 250k and 320k on and NEVER had this kind of nightmare, it has ruined my summer. We've had record heat here and my AC does not work with this problem also. I have an appointment on Mon. at the Subaru dealer.. will this nightmare end or continue?
Car started idling very rough after I pulled up to a stop light off the freeway to get gas. Rough idle went away after I accelerated through the light, no engine light. 2-3 weeks later rough idle returned during work commute with engine light solid and cruise light flashing. Pulled codes showing a misfire in cylinder 2&4. I changed all 4 plugs, and swapped the coil packs to isolate problem coil pack but misfire continued in cylinders 2&4. Taking it to the shop soon, I suspect bad wiring. Will update upon inspection.