Friend of mine lives a few hundred miles away and the shop said she needs a new engine due to a cylinder misfire yesterday.  Light came on, no drivability issues, 145k.  Plugs/wires are unknown, timing belt replaced already.

 

 

I spoke to them on the phone and they said they "tested all the sensors and spark plugs and wires" - but didn't say how.  

They said it's intermittent so it can't be the plugs/wires, and they found some service bulletins on hanging valves.  That doesn't seem like enough to go on to verify a hanging valve, but it's possible the guy I talked to wasn't the guy doing the work. 

 

Check engine light came on, no drivability issues.  It's like 145,000 miles and spark plugs and wires are unknown.  Timing belt was replaced a few years ago.

 

I'm thinking it's just plugs, wires, and maybe oil in the spark plug tubes from the valve cover gaskets.

 

As of now she's driving 6 hours next weekend for me to work on it. 

wow, now I've heard it all ! Need a new engine at 145,000 on a subaru...... All for a check engine lite ??? A misfire!  A few drops of water getting by the filter will throw a misfire code. Sounds like they want to make money from your friend, not fix her car. Shops like that are why people hate mechanics.  

I think one of the tests you can do with a vacuum gauge  is to watch for flutter that a sticking valve might cause.

 

but it is VASTLY more likely she has a tune-up related problem as opposed to an internal engine issue.

 

I have seen a video and pics of 'dropped' valve guides on some engines, I think it's possible under severe abuse/lack of maintenance I guess....?

I wasn't able to get a clear answer if they did any specific tests - maybe just because the guy i was talking to didn't work on it, he was reading and fumbling with paperwork on the phone. 

but i was suspecting it's a misdiagnosis. 

 

my hesitancy is because she's gotta drive like 6 or 7 hours for me to work on it next weekend so i'd hate to be wrong and second guess someone that actually drove, looked at, read codes, and spent some effort diagnosing it.

Call back ,arrange to talk to the guy who diagnosed it. He may have good reason.. but really have you seen a subi yet that lost a valve at 145,000 ?  Maybe under race conditions but a go to work car that has been properly maintained ? If I read your post right , it was running normal and  her check engine light came on so she took it in to see why ? Or was it running like xxx ? I understand your hesitancy to say drive it 6 hrs.  She could try another shop locally to get a second opinion... but if it was/ is running normally and you would like a visit, then after her tune up tell her that you'll grill steaks if she buys the beer.  

Spark plugs and wires fixed it.  She made the 12 hour round trip and all is well, no "new engine needed". 

 

Before she left I asked the guy over the phone if it could be plugs/wires and he said "They tested fine, they wouldn't be intermittent". 

 

Anyway they were autolight plugs with 0.078" gaps and showing considerable wear.  Factory is 0.039-0.043 or something like that, so nearly double the gap and not great pugs for subarus. 

yikes - that's quite a gap.

 

hope she can locate a different mechanic local to her when she gets back.

 

glad it was kinda simple to fix.

She's got a possible connection with reasonable drive she's going to try out.

The wonders of the Subaru! Somehow runs at all with a .078" plug gap! 

The wonders of the Subaru! Somehow runs at all with a .078" plug gap! 

 

...and with crappy Autolite plugs! Astounding!

so i guess 0.078" is a lot?

 

i've never measured old plugs or paid attention really - just change them out.  the newer H6 plugs never even seem warn at all.  

Yeah the ones I pull out of my Ej22s are usually .060 - .065" when I change them after about 30k miles. 

 

I've bought different plugs for both of them instead of plain NGK coppers the last time I changed them though. Gonna experiment a bit and see how long some different types last.