05 forester xs 2.5 non turbo , just had tappet gasket kit done aswell as new nkg leads and plugs. As the old gasket leaked and soaked them with oil . Here is the problem, since this was done one cylinder will not fire when idleing , not an issue before the gasket change. . Did all the swapping of Leeds and plugs to check for faults in new items. To the point of pulling the leed from the plug and it having no affect on the idling motor.

All work in other cylinders. So it's the air box side rear cylinder being a thorn in my side . Ran copious cleaners directly through inlet manifold and with fuel . Sorry if this has been on other forums I didn't see it . Cheers. its the wife's little joy ( the car ).

Other thing is , all I can smell is unburnd fuel from the exhaust. Hope someone outthere can help

 

Cheers

Kinda sounds like a burned valve.

Did you check and/or adjust the valve lash clearance when the valve cover was off?

Thanks for the reply .the mechanic tells me that the clearances were done while the cover was off, were a bit stiff to adjust

I think we need to know for certain whether or not the spark plug is firing.

 

Have you verified that cylinder has no spark?

With a timing light or pulling the plug wire and watching for spark?

 

If you swap wires it still does the same thing - no spark using two different wires?

 

Or by "firing" do you simply mean that cylinder is dead?

If that's the case I'd be checking valves like fairtax said - maybe something went awry while adjusting or there's a shop towel stuck on the valve (just kidding)....but something?

compression test might be the simplest valve test at this point - pull plug and test.

just a last-ditch idea, maybe drop the ex manis and look for a 'dropped' valve guide?

thanks for your thoughts, mechanic said that he checked compression and was ok said all this when we got it back . I pulled the plugs and Leeds and they are working ok . All this is only at idle. There is oil residues on the ceramic partt of the new spark plugs an issue maybe ?

Hi,

Fuel smell is due to the un-burned fuel in the non-firing cylinder.

There shouldn't be any oil on the plugs. It's common for the gaskets on the plugs to fail and cause misfire issues, but yours was 'fixed'?

GL,

Td

I'll have to find out whether the spark plug recess seals were done with the tappet cover seals. The spark plug is arcing when removed. To the point that it's arcing to the block from the connection boot when I pull it off the spark plug.

Just to follow up , found a Subaru guru , and he found a fault code for the idle control. Which did not show jnr all the electronic harness were disconnected and reset. There must be be a tell fault code interlinked not related to the specific problem(which the engine management system cannot read ). So when it was reset it fixed the problem somehow .so it did have spark but sequence timing was out , then caused a misfiring idle . Puring like 200000 km kitten now . Thanks again for you thoughts earlier.

Disregard the jnr . Typo.