Jump to content
Ultimate Subaru Message Board

06 Tribecca 2-4-6 missfire HELP


Recommended Posts

Hello team.  I am reaching out before i start spending time diagnosing to see if any of you have run into issues with the 06 era H-6 3.0 engine that has a dead miss on three cylinders. ( 2 , 4  and 6)   Just seeing if this is a know issue before i waste time/money. Thanks,Craig

 

Link to comment
Share on other sites

Compression is easy enough to check but was it blowing smoke before the misfire issue? I'm wondering if it isn't just dumping unburned fuel into the exhaust.

 

If you pulled the plugs and the tube seals are leaking that could also cause it to smoke for a little while.

Edited by GreaseMonkey03
Link to comment
Share on other sites

all 3 failing in nearly similar fashion is interesting. 

 

extensive carbon build up in the intake/valves/combustion chamber is my first guess based on experience.

 

Random guessing:

would timing chain tensioner issues impact timing/cam sensor?

FPR - can those affect one side?

Unlikely but if someone hacked a spark plug job the plugs, coil packs, could be problematic.  Make sure they're replaced (wouldn't be the first time i've seen half of spark plugs replaced), COP's seated and not installed on the wrong cylinder (which they're so tight i'm not sure that's even possible). 

Link to comment
Share on other sites

Anything related to cam/crank sensors would throw a code. I'm guessing he checked codes because he knows which cylinders are misfiring.

These are coil over plug, the likelihood of all three coils or plugs going at once is unlikely.

Ditto on the carbon build up. One or possibly two cylinders could possibly be affected but the likelihood of three and all on the same bank is also unlikely.

You will want to look for ONE issue that will by itself cause all three cylinders on one bank to misfire. That's really where you want to start.

It could be a ground, a vacuum leak (although this will usually be accompanied by a random multiple misfire code or affect both banks) or even a break in the harness (those pesky mice might be at it again)

For multiple individual components (like valves) to foul up on one bank only and all at once is damn near impossible.

Keep it simple. Check the small stuff and go from there. I put a Japanese motor into an American TriBeCa not too long ago. These motors really aren't that complex. Aside from having to swap over a few components, they're simple creatures.

If you have a scanner, check for pending codes or history codes. There may be some hidden gems in there that could give you more information.

  • Like 1
Link to comment
Share on other sites

fuel rail is common - and I think it has it's own regulator/pulse absorber gadget

 

valve advance system is common, but I'd expect a code other than just misfire.

Not always. If head work has been recently done and some of the oil galley plugs were not put in, it can cause a misfire on all 3 cylinders on one bank without throwing any VVT codes. I've found out from experience on that one.

 

How many miles are on the car?

When was the last time the spark plugs were changed?

What brand and grade of gas is typically used in this vehicle?

What is your oil change intervals?

 

The second generation EZ30 are known for cracking heads from the cooLing system into the combustion chamber as well. Have replaced a pair of heads on one engine, replaced a head on another, and replaced an entire engine because of this problem.

  • Like 1
Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...