2002 Subaru Outback idle shake/misfire

Tiny
THEBEAR1441
  • MEMBER
  • 2002 SUBARU OUTBACK
Shakes or Wobbles problem
2002 Subaru Outback 4 cyl All Wheel Drive Automatic 106*** miles

2002 outback 2.5 106***mi. I have been having a misfire problem for 4 months that no one can seem to find out the engine spun a bearing and the entire long block was rebuilt at 102***mi. The misfire hapens under no load during the warm up phase then gets better once warm this happens apx every 3 days I will have somthing replaced hoping to fix the prob have cel reset then it will come back on in apx 3 days always during the warm up phase and the the cel will stay on till next time its reset although one time I drove it for like 10 days with light on and it shut itself off only to reapear in about 2 days the code is always p0304 cyl 4 misfire no other codes the car shakes at idle during warm up and is more noticable when you are stopped with it in drive then once it is warmed up it gets a little smoother here is my long list of expensive repairs that have been perfomed
new: spark plugs 2 different sets
new: wires 2 sets also
new: ignition coil also 2 thought first was defective
new: cyl 4 fuel injector
new: ecu
new: wire harness think the one going to the injectors
new: alternator and battery dealership said output was low at 60amp or volt witchever it is instead of 90

new: airfilter

atleast 4 different compression checks at diferent facilitys all say compression is good and a leak down test also found no leaks

sprayed brake cleaner I think? Around intake gaskets vacume lines cant find any vacume leaks intake leaks

dealer said fuel pressure was good new fuel filter

ENGINE RUNS GREAT UNDER ACELERATION NO POWER LOSS NO STUTERING NO BACK FIRE RUNS REAL SMOOTH

THE SECOND YOU LET OFF THE BREAK WILE IN DRIVE THERE IS NO MORE SHAKING EVEN DURING WARM UP WHEN THE SHAKING IS MUCH MORE NOTICABLE

EXHAUST HAS BEEN PRESSURE TESTED AND IS GOOD

WHILE DRIVING AROUND THROUGHOUT THE DAY I SOMETIMES HERE LOUD CLICKS KINDA SOUNDS LIKE A PEN CLICK BUT LOUDER MAYBE A RELAY / FUSE POP

BUT HAVE ALSO TESTED EVERY FUSE AND RELAY AND ALL LIGHT UP

THROTTLE BODY WAS KINDA DIRTY SO CLEANED IT ALONG WITH THE IDLE AIR CONTROL VALVE AND NO DIFFERENT

THIS IS COSTING ME A FORTUNE I HAVE TO FIND THE PROBLEM PLEASE HELP ME WITH SOME IDEAS OF THINGS TO LOOK AT AS MY MECHANIC/S HAVE RAN OUT OF IDEAS SORRY FOR THE VERY LONG POST
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Thursday, September 18th, 2008 AT 3:23 PM

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Tiny
RASMATAZ
  • MEMBER
THE SECOND YOU LET OFF THE BREAK WILE IN DRIVE THERE IS NO MORE SHAKING EVEN DURING WARM UP WHEN THE SHAKING IS MUCH MORE NOTICABLE

Could be a problem with brake vacuum hose/check valve and brake booster leaking

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

A misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.
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Thursday, September 18th, 2008 AT 4:55 PM
Tiny
THEBEAR1441
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Checked booster and vacuum line master cylinder full of brake fluid see no seepage and no air leek would like to check the egr valve to make sure valve is not stuck open but for the life of me cant find the egr on this car
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Thursday, September 18th, 2008 AT 11:45 PM
Tiny
RASMATAZ
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I don't think it has one but the 3.0L does.

Use the cleaner and spray it while engine is warming up, when the idle smoothes out that's where the leak is.
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Friday, September 19th, 2008 AT 5:47 PM
Tiny
THEBEAR1441
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What type of cleaner are you saying to spray brake cleaner? And where? On vacuum lines. Because that was done by my mechanic and no leaks were found like mentioned in my first post. Could that be because it was not done during the warm up phase when the rough idle is more pronounced? Also I have been able to find a egr valve for the 2.5L on autozones website but also found a maf that I think this car doesn't have so I guess the egr may not exist eighter. Unfurtanatly I dont know everything about this car I have no mechanical training only trial and error though I have learned alot through this ordeal I aprecate your help and ideas please let me know if there is any more info I can give you that might help reach a conclusion to this drama.

Ps I forgot to mention in my first post that last week when the subaru dealer replaced my battery and alternator because of low output they also replaced front o2 sensor that was giving a abnormal reading
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Saturday, September 20th, 2008 AT 12:08 AM
Tiny
RASMATAZ
  • MEMBER
You can use WD-40 and spray in between the intake manifold and the cylinder head. Also disconnect the brake vacuum hose from the intake manifold-plug it and see what happens to the misfiring.

Leaky vacuum hoses Replace them. If the end of a hose is loose or cracked, cutting it off and sticking it back on may temporarily eliminate the leak. But if the hose is rotten or age hardened, it needs to be replaced. Shortening hoses may also create additional problems. The hose may chaff or rub against other components, or pull loose as a result of engine motion and vibration. Use the correct type of replacement hose (PVC hose or vacuum hose capable of withstanding fuel vapors and vacuum without collapsing). Also, be sure the replacement hose is the same diameter and length as the original.

Carburetor or throttle body base gasket vacuum leaks Try tightening down the carburetor or throttle body mounting bolts. If that doesn't stop the leak, replace the gasket under the carburetor or throttle body. If there is a heat insulator or adapter plate under the unit, it may also have to be replaced depending on its condition. While the carburetor or throttle body is off, use a straightedge to check the base for flatness (and the manifold, too). Warped surfaces can prevent a tight seal, so if you find any it calls for resurfacing or component replacement.

Carburetor or throttle body throttle shaft vacuum leaks Wear here can only be repaired by resleeving the throttle shaft, which for all practical purposes means replacing the carburetor or throttle body with a new or remanufactured unit.

Intake manifold gasket vacuum leaks Try retorquing the intake manifold bolts, working from the center out in the recommended tightening sequence. If that fails, the intake manifold will have to be removed and the intake gaskets replaced.

Sometimes the mating surface of the intake manifold or the heads will not be flat (check both with a straightedge). If warped, the intake manifold and/or heads will have to be resurfaced on a milling machine. Another problem to watch out for here are heads that have been milled or resurfaced to raise compression. To maintain proper alignment between the manifold and heads, metal also needs to be machined off the bottom of the manifold where it mates with the block, otherwise it will sit to high and the ports and bolt holes won't align.
EGR valve leaks If the valve isn't closing all the way due to carbon deposits on the stem or valve seat, cleaning may be all that is needed to cure the problem. Otherwise, the engine will need a new EGR valve.

Leaky power brake booster Replace it. But first make sure it is the booster and not just the hose or check valve that is leaking.
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Saturday, September 20th, 2008 AT 12:19 AM
Tiny
RASMATAZ
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Hook up a vacuum gauge

INTAKE SYSTEM LEAK: with engine running at idle or fast idle speeds needle reads between 3 and 5. Check induction manifold gaskets.


http://www.2carpros.com/forum/automotive_pictures/12900_vac14_1.gif

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Saturday, September 20th, 2008 AT 12:28 AM
Tiny
THEBEAR1441
  • MEMBER
Ok so I sprayed around vacuum lines intake exc. W/wd40 and noticed no change in idle stayed right at like 750. When I unplug booster vacuum line rpm jumps to about 1100 rpm, then when I plug the hole on the intake manifold with my finger idle drops to about 500 like its going to die then resumes without dying at 700-750 I would assume that's normal is it?

I also had someone power brake the car to check engine mounts as I can not see any visual cracks or wear on the rubber we power braked it by quickly hitting accelerator up to 1500 a few times while in drive and the engine had id say 1" and a half or so of movement is that a normal amount of play?

Also the dealer thinks next step should be a valve adjustment could this cause the shaking at idle in gear when stopped but no shaking once moving or in other words shaking under no load.

I have also read that rebuilt engines should have a valve adjustment after the break in period or like 1000mi wich mine has not do you find this to be true for my car its a ej25 engine the ones with the lovley head gasket failure
thanks for you help
Ryan
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Saturday, September 20th, 2008 AT 12:24 PM
Tiny
RASMATAZ
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1and 1/2 is excessive replace the mounts and valve adjustment after 500 miles should be done and head/s be retorqued
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Saturday, September 20th, 2008 AT 1:18 PM

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