2004 WRX misfire in cylinder 4 and sometimes 2.

Asked by Jan 24, 2013 at 03:54 PM about the Subaru Impreza

Question type: Maintenance & Repair

2004 wrx 177,000 miles.
Cylinder 4 misfires at low rpm. CEL blinks at low rpm then goes out at around 3000. Will do this a few times before cel stays on. Have replaced coil packs and plugs. Bought a scanner and everytime cel is on its for a cylinder 4 misfire. Compression in cylinder 4 is also about 20 psi lower than others 120 vs 140. Car runs well, no backfires . doesnt smoke or burn oil. Mechanic thinks it may be a bad exhaust valve.
Your thoughts?
Worth fixing?

5 Answers

'Worth fixing' is partially a personal rather than a pragmatic question. Depends on cost, and at 20psi lower, I think no worries, I wouldn't put a dime in it at this stage, might as well do a valve job if head is coming off not one exhaust valve, and only slightly bad at that, Nah. Drive 'er to the moon

1 out of 1 people think this is helpful.
35

I had that issue, then it got worse and would misfire constantly, a new O2 sensor sorted that out. I wouldn't worry about doing a valve job unless you were seeing a number under 100psi.

1 out of 1 people think this is helpful.
445

100 bucks says you have a bad ringland. Oil will seep past the rings and lower the octane of the fuel, which causes knock and misfires. Shortblock will need to be rebuilt, the issue will only get worse. It is better to do it now while you still have a usable block.

Hey did u ever find out what was causing ur miss fire I have the exact same issue going on and I can't figure out what's going on with!!

??

Your Answer

Add photo

Related Questions

Impreza

Looking for a Used Impreza in your area?

CarGurus has 16,732 nationwide Impreza listings starting at $1,800.

ZIP:

Search Subaru Impreza Questions

Subaru Impreza Experts

#1 TheSubaruGuruBoston
TheSubaruGuruBoston
Reputation 570
#2 Nick Eidemiller
Nick Eidemiller
Reputation 450
#3 Tom Demyan
Tom Demyan
Reputation 290
View All

Related Models For Sale

Used Subaru Impreza WRX
42 Great Deals out of 1,177 listings starting at $995
Used Subaru Outback
363 Great Deals out of 36,143 listings starting at $1,799
Used Subaru Impreza WRX STi
22 Great Deals out of 573 listings starting at $2,900
Used Subaru Legacy
244 Great Deals out of 16,551 listings starting at $2,195
Used Subaru Forester
319 Great Deals out of 26,944 listings starting at $1,995
Used Subaru WRX
21 Great Deals out of 3,822 listings starting at $19,990
Used Honda Civic
496 Great Deals out of 89,086 listings starting at $1,299
Used Mazda MAZDA3
211 Great Deals out of 30,703 listings starting at $1,495
Used Subaru Crosstrek
28 Great Deals out of 12,403 listings starting at $18,000
Used Honda Accord
781 Great Deals out of 87,677 listings starting at $1,250
Used Toyota Corolla
689 Great Deals out of 72,761 listings starting at $600
Used Subaru WRX STI
19 Great Deals out of 1,442 listings starting at $24,995
Used Honda CR-V
807 Great Deals out of 59,586 listings starting at $900
Used Ford Focus
552 Great Deals out of 56,652 listings starting at $800
Used Subaru BRZ
14 Great Deals out of 963 listings starting at $10,900