Cylinder sleeve blows out

[ThosL]

I was trying to pull out my driver's side spark plugs to check them out.  So I put in the spark plug socket wrench, turns and turns and it is one of the lower quality ones that are a pain to get out.  I tried to pull it out with pliers, no luck.  So then I started the car up and somehow the cylinder sleeve blew out, I could not find it anywhere but could see the hole.  What is the process for replacing these?

[1 Lucky Texan]

um - I suppose you mean the spark plug flew out and has stripped part of the threads out?

 

maybe I'm confused but, it seems you may be best to get a used or rebuilt head for that side of the car.

 

any pics of the plug and the hole? maybe using a mirror will get some nice pics too?

[ThosL]

Ok, so there is no sleeve the spark plugs sit in?  I looked on the internet for a diagram or picture, couldn't get what I was looking for.  Thanks for the clarification.

[1 Lucky Texan]

well, there is a 'tube' around them on DOHC engines. That is, on your engine, did you have to put the socket inside a tube in the head to seat it onto the plug?

 

what car/engine is this?

[ThosL]

Engine ej22--96.

[Fairtax4me]

There's no sleeve. The plugs thread straight into the cylinder head. 

Time-sert makes thread inserts specific for spark plug thread repairs, but they're expensive. 

 

A helicoil kit can be used if you feel comfortable doing that. Otherwise, looking at replacing the head, which is gonna be in the $700-1,000 range if you pay a shop to do it. 

 

Used heads can be bought for around $100 per side or less if you look around. Then gaskets and fluids will be another $100-150ish. 

[Bushwick]

Why did you try cranking the engine with a plug almost out?

 

A "cylinder sleeve" is a sleeve used in aluminum blocks so the piston has a harder material for the rings to seal to.

 

Plugs just thread out of the head. If you are lucky, the plug was basically all the way out and the force from the compression blew it out, w/o damaging the threads or worse, ingesting small amounts of aluminum.

 

Inspect the spark plug's threads for damage. If it hit the ground, it might have cement damage. I suggest gapping a new plug and threading it by hand, and see if it'll actually seat or not. Use another plug as a reference for how many turns it takes BY HAND to seat it. If your new plug goes 1 turn then no further for example, chances are the threads in the head were damaged and need chased with a tap, which won't be easy due to tight confines, plus you must be careful not to drive any bits into the combustion chamber.

[The Dude]

I am sorry to hear of your troubles. In the future I would suggest applying anti-seize compound to the threads of the spark plugs. Personally, I use a torque wrench each and every time that I change the spark plugs. It is very easy to strip aluminum threads.

Edited February 18, 2016 by The Dude

[ThosL]

Yes, I went back out to where it was parked and tried to thread it--no dice on that--stripped.  I called the local Subaru expert and they said helicoil is an option by an expert who knows how to drill it and do the job.  

 

No excuse--I was working on it outside in a park area with high wind velocity temps in the 20s and lost my concentration.  Part of the problem is crappy spark plug socket from Walmart.  Once you get it in it is hard to get it back up.  Needlenose pliers?  I don't have many tools and they are substandard.

 

Is there a way to drive it on 3 cyls. without the terrible noise??

Edited February 19, 2016 by ThosL

[Fairtax4me]

Unplug the fuel injector. It'll still chuff as air is forced in/ out of the plug hole, but it can be driven that way for a short time.

[Bushwick]

Try and wedge a mirror between the valve cover and frame rails, tilting the mirror as much as you can, while shining a flash light into the mirror. One of those hand mirrors women typically use with a handle works.

 

Try and see if any of the threads are actually broken out or not. If it's only a couple rows of threading, there will still be enough in there to get the plug secured. 

 

Run up to a Harbor Freight and buy one of their thread tap kits. If need be, run up to an Auto Zone 1st and go to their nuts/bolt aisle, and look for a hanging bolt thread identifier. Thread your good plug into the holes until it threads all the way through. If they have mounted to a shelf and you can't get threading through, find an actual nut (can very easily slide small carton open, pull nut out, see if it fits, make note of size and thread pitch) and compare until the plug threads all the way through, then you'll know which tap set to get.

 

Since the taps are similar in length to a drill bit, and have a " T " style attachment, it's quite possible you can start the tap by finger, then attach the handle and have enough room to chase the threads.

 

If you use a rugged paper towel (the blue paper towel rolls you buy at Auto Zone work great and won't disintegrate) rip a section off, then very carefully stick in the hole, just enough to clear the bad threads. I strongly suggest hand turning the engine FIRST (use mirror and light for ease) and get the piston to the top of it's travel as that'll limit the paper towel falling to far in.

 

Once the piston as the top, and you've plugged the hole, apply some oil to the correct tap and very gently start chasing the treads. I suggest removing the chase after every 1/4 turn just to be sure you are NOT cross-threading. You'll be looking for clean, consecutive threads, as you'll want yours to perfectly match with what's there.

 

Once the chased threads match to the existing threads, remove the tap, and spray it down with WD-40, degreaser, or whatever you have on hand, apply fresh oil, and just keep threading (it shouldn't provide any new force) it and unthreading it, and wipe off again. Hopefully you'll get most of the metal bits sticking to the tap. 

 

If you can get the opposite side of the car raised high enough, you might be able to spray some WD-40 in and have it drain out on it's own, as the spray + gravity might be able to get most of the loose debris out. Otherwise, if you have a shop vac, you might want to put the hose on the exhaust port, then ram a 3/4" heater hose onto the end, and bend that somehow (stick a coat hanger end into the hose doubled up and the heater hose should hold form) and starting from a distance of maybe 6 to 8", start blowing toward the TOP of the valve cover where the hole is. The idea is the turbulence across the hole will hopefully dislodge any material w/o moving the paper towel. You can carefully move closer to the hole, and anything left should be ejected. From here, if it were me, I'd apply light coat on another section of paper towel, twisted down to size of hole, and try "threading" that into the hole, taking caution NOT to push the paper towel plug in further. Then unthread that, and inspect if you are getting any more debris sticking to the paper towel.

 

Once that appears really clean and it looks like you got everything, carefully stick a small 45 degree pick into the hole (can grab a set of cheap picks for $5-8 anywhere; Harbor Freight sells them cheap too) and turn it counter-clockwise so it grabs your paper towel "plug" and unthreads that. 

 

Go back with the mirror and inspect you got all the crud out. If you apply a small dab of anti-seize on new spark plug (just apply light coat on threads, as it's threaded in, it'll coat the entire plug; too much and it can get on the plug tip, which you don't want; keep it roughly 3 threads from tip of plug). Thread that in by hand then unthread. Wipe it down and inspect for any foreign metal. If clean, reapply and thread plug all the way in, then carefully tighten to spec, but do NOT over tighten.

 

 

That might seem like a lot of work, but the main concern is keeping the shavings out of the combustion chamber. A small dusting might not hurt anything, then again a section of threading can potentially damage a valve. 

 

This option is cheaper than pulling the head and less work, though you do have the option of pulling the head, chasing the threading out with head on a table bench, wiping everything down, then reassembling. The hardest part for you will probably be the timing belt if you never did one before, plus you'll have coolant everywhere, will need a new HG, might need new head bolts, etc.

 

If it were me, I'd try and repair the threads with head in place if possible as that'd be the cheapest path, but it depends mainly on how many threads were damaged in the head.

Edited February 18, 2016 by Bushwick

[ThosL]

Thanks for the thorough advice; but I'm no good with that level of detail and careful step by step installation, etc..   Definitely the spark plug will not thread.  The reason I wanted to get this done, but stupidly did it under adverse conditions, was the misfire diagnosis on driver's side, both cyl.s.   I called an excellent shop in Norwalk, and will copy out recommendations for them to look at on Monday.   They will try the helicoil option.  

[Bushwick]

Heli coil would be an option if most or all the threads were destroyed. It sounds like you had it unthreaded, most if not all the way? If it was all the way unthreaded and plug hit cement, that could prevent that plug from threading back in. A mirror could tell you if the threads in the head are even damaged. Not sure why you'd want to heli coil if it's a couple threads or none at all that are damaged.

 

Heli coil is a wire that coils into what's left of a severely damaged hole, and tries to provide something for the new plug to grab. It's not a permanent fix. Chasing damaged threads is the correct method.

 

Any of this being done by a shop, will cost more than it'd run to replace the entire head with head gasket and fresh coolant. But if you don't want to even see if the head threads are damaged, then you'll pay $$$ for that. 

[ThosL]

The garage said they could try the helicoil or other fix with the head in the car--it doesn't need to be removed for that does it?  If they were pulling the head then replacing it would make sense but that is very involved and expensive.  Is there anyway to weld or epoxy a plug into the head as a last measure?  With over 300K miles I doubt it is going to need another plug replacement.

[ocei77]

I helicoiled a 2.5 sohc in place on a 2008 Legacy. You can do the same.

Follow instructions.  Put cylinder at tdc .Use  a heavy grease on the tap to grab any metal chips.

You shouldn't have anything left, but if you want, you can vacuum.

Still going strong over  a year later, as a DD by a twenty something.

 

O.

Edited February 19, 2016 by ocei77

[ThosL]

They say you have to drill out before helicoil; no way to reach the spark plug cyl with a drill and limited access.

[AdventureSubaru]

Have you even tried a thread chaser yet?

 

If I've read right, all you've done so far is try to thread the spark plug down the buggered hole. If there are threads left a thread chaser will open up the top and only afterwards you'll be able to reinstall the spark plug.

 

Helicoil is an option. Some will last forever and some are time bombs.

 

Good used head is the most reliable option.

 

Can I kick you in the pants for ever thinking it was a good idea to start the car with the plug only partly set? Geez.

[idosubaru]

1.  chase the threads - install a new spark plug - as aleady mentioned you likely didn't strip them all

2.  helicoil - get a long drill bit or extension

3.  get a "no drill required" kit: 

http://shop.advanceautoparts.com/p/fix-a-thred-m14-1.25-plug-saver-kit-1-each-insert-s-n-l-98141/9020056-P

 

i'm pretty sure seeing a repair kit 10 years ago that's a self tapping insert - which then has a different (smaller) sized spark plug you thread into it.  but a search yielded nothing, maybe i'm dreaming. 

[ocei77]

There is a helicoil specifically made for spark plug repair. It catches whatever threads you have, and cuts new ones. You then seat the threaded insert and use the same plugs.

It uses a ratchet so you'll have enough room.

 

O.

[DaveT]

A trick I found to help avoid this sort of problem - run the engine up to normal operating temperature. Then remove plugs or bolts etc. That have not been turned in a long time. Reassemble with anti seize. Be careful with torque since the anti seize is a good lubricant.

[1 Lucky Texan]

man - when things go south, the expertise on this forum really shines.

[ThosL]

OK, thanks.  I walked up the few miles to retrieve my car this morning, didn't know whether driving on the 3 cyl.s was worth doing, better than tow truck.  I passed a Hispanic mechanic working on a truck nearby and he said he would check it out in an hour.  So maybe I make progress today.

[ThosL]

I picked up the Helicoil set at Advance like Gary recommended, but I'm assuming that I would need a specific socket for that thread chaser, etc..  What are mistakes that could be made here; vs. level of expertise required; minimum tools to do the job in a parking lot?

[ocei77]

Read the instructions completely before you go out.

IIRC about 19mm or so.

Put cyl at tdc.

Use a heavy grease on tap to grab chips.

Go SLOW.

Take a few extensions for the socket and a small hammer to set the insert.

A few rags. And of course a spark plug.

If I have left something out, someone can add/correct.

 

O.

Edited February 19, 2016 by ocei77

[AdventureSubaru]

Am I still reading right? Proceeding with a helicoil without ever trying a thread chaser? Like doing head gaskets without checking to see if you've got a coolant leak or faulty thermostat.