[outbackinpa]

I have an 05 XT...last summer I get the CEL on. Pull the codes and it shows a cyl 2 & 4 misfire.

Do a compression test of all the cyl's and they were all within a couple psi of each. Renew the plugs with the correct NGK iridium units and new coil packs for #2 and #4.
CEL goes away, car runs fine....

Wife comes home a few days ago and announces the CEL is on again. Pull the code, cyl #1 misfire this time. I say enough and order 2 more coil packs. Install coils and clear code.
The wife gets 2 days of driving and the stupid CEL is on again. Pull the code and it is cyl #1 misfire again. WTH
Vac. leak? Gremlins? The plugs have 3000 miles on them and I was careful when I removed and installed the coil pack/boot assembly.

I am starting to question my XT purchase. Any ideas?

Thanks for the space.

 

[tdelker]

You need to do a leak down test...

 

[outbackinpa]

I have an 05 XT with 118,000 on the clock. The engine has developed a miss which set off the CEL.
Took the car up to my friend's garage and put it on his scanner. It came back with the No. 1 cyl misfire P301 code.
Last summer I had the same issue with No. 2 & 4 misfire. I performed a compression test with consistant numbers in all 4 holes so I installed new OEM NGK plugs and coil packs on the 2 & 4 cyl. and that took care of the miss.
This time I thought, ah-ha must be the coil pack so I ordered and installed new coil packs on 1 & 3. Still have the miss.
Back to my friends garage...swap injectors from No. 1 to No. 2. Code reappears.
Back again...pull the 1 & 3 coil packs and plugs. Perform a leak down test and the 1 & 3 cyl are almost identical so we swap plugs and keep the coil packs in the same position. Still have a miss.
Back again...pull the coil pack on number 1 and check for spark. Plenty of spark is present with the tester.
Thought a vac. leak might be the cause....get out the smoke machine. No leaks.
He pulls up his all data and it notes on 80,000 mi + turbo motors a problem with valve guide failure and another valve issue. Both he and I are against the wall on this...The service guide he had recommended valve adjustment but after viewing the subaru setup he said it looked very similar to the VW and Audi approach to valvetrain.
Has anyone ran into this with their car and can shed some light on this or give me a direction to research.
I really don't want to pull the engine to get into the cyl. head.
Thanks for any help.

 

[tdelker]

Don't post in multiple places. People will respond.

As previous asked and answered (in this and the other thread) - leak down test.

 

[outbackinpa]

Thanks for the reply. I performed the leak down test as was suggested. That was what I included in my listing of the trouble shooting process.
We pulled coil packs and plugs on 1 & 3. The leak down readings from 1 & 3 were almost identical.
That work took place Tuesday evening.
Wednesday evening was spark check at the coil pack and a smoke test for a vac. leak.

 

[tdelker]

Sorry, missed that.

Intake manifold gasket? There is a known issue, usually on 07, but could effect 05 with the intake manifold gasket. I suggest spraying some start fluid around and see if the RPM pick up.

 

[mr3wan]

So I would say its possible the valves need some adjustment but I can't confirm for sure.

I had a timingbelt failure (idler pulley went bad) at 80k which killed the engine and needed new values. After the work was done and I got the car back I noticed it was a bit rougher on idle and would periodicity throw a check engine light. Most of my CEL's were Cyl2 but I also got them on Cyl 4. I tried swapping coil packs / spark plugs but none seemed to have an effect.

I took it back to the dealer that serviced it and they found during repair they had tightend valves to 2.5 SOHC specs and not 2.5 DOHC (turbo) specs. Once they re-did the valves the car ran perfectly.

Thats my 2-cents on why it could be valvetrain related...

 

[Seabass]

Look for vacuum leaks before you tear into the engine. If you buy a vagcom cable and download learningview from romraider.com, it will give you a snapshot of the fuel trims. That will tell you if there is a leak.

 

[outbackinpa]

Guys,
Thanks for the insight.
Seabass, tdelker-my buddy has a smoke machine (part of his ongoing attempt to support the local Snap-on dealer) and that is what we did Wednesday evening after the coil spark test. Removed the air cleaner hose,plugged the tube...disconnected the vac. hose to the power brakes and attached the smoke hose. No smoke was observed exiting the engine.

My buddy has the Mitchell/snap-on service and got online to research their hit list for the turbo cars. They listed at 80,000 plus a problem with valve guides pulling out and hanging the valves and a couple of valvetrain related issues.
He said that the valvetrain configuration<the need for shims of a unique thickness>was similar to an Audi/VW setup he had repaired...and that they were a PITA.

Mr3-It is a head scratcher as the original owner was a take it to the dealer by the book kind of gal. Timing belt at 95,000, Subaru replacement battery, she even purchased their winter blades. I spoke with the dealership that maintained the car, they knew her by name. I guess it is just my luck. I will talk to my friend about the valve reset...It can be completed in car? As you all know, it is so tight between the head/valve cover and the unibody frame?

I really don't want to go down the engine removal road!!!

Thanks again for taking your time to try to help a fellow XT owner.

 

[Radar]

I recently had a misfire code on my '05 XT. My mechanic tracked it down to a bad injector. He cautioned me that had I driven the car hard while misfiring, bad things could have happened. No reoccurences after the injector was replaced.

 

[tdelker]

My ignorance on the smoke machine. I am not sure how effective it is on intake manifold leaks, but it it pressurizes the whole intake area, I suppose you should see something.

I certainly would look elsewhere before you blame valve guides.

You probably should look at get the freeze frame data from the misfire or even a full run with some type of logging software when the misfire occurs and post on here and see if anyone can decipher the data (like cardoc). That is going to give you the most complete picture since it appears you've checked all the other boxes.

Tom

 

[outbackinpa]

Radar,
Thanks for the reply. We had a similar thought so Tuesday evening we swaped the injector from cyl #2 into the cyl with the miss and then cleared the computer.
Wife took the car to work and the CEL light came on. When we brought the car in Wednesday night my old friend P301 Cyl #1 misfire came up on the scanner. In our mind, that took the injector out of the equation.

Tom-thanks for your thoughts. Like you said, my buddy and I have checked most all of the boxes that should point to the problem area. It is kicking our rearends!

 

[tdelker]

I suspect it is a poor sensor sending misinformation. Logging data should help you answer which one, if you know what you are looking at (I dont!).

Tom

 

[skiwhmts]

I had the same problem and my local shop could not figure it out and they are good mechanics. I think it was a bad solenoid valve going to the ignition wire. I will need to check on that. was about $250 at dealer to fix. only a dealer and they are good too has the equipment to verify. I have a 2008 XT with 110,000 miles which I love for reference.