Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

reusing ej series mls head gaskets that haven't been heat cycled

Featured Replies

I want to make a survey only of those who have actually reused mls ej series head gaskets that have not been heat cycled.  This thread is intended only as a survey of those who have done this.  I did a dumb mistake the other day and needed to remove a head that I just had milled.  I had torqued the head bolts before I noticed my mistake but hadn't assembled the engine any further.  I pulled off the head and looked at the head gasket closely.  I didn't notice any damage to the gasket and the gasket looked like new.  Two local repair shops said they would buy another and it wasn't worth the risk to reuse the same gasket.  The owner of the machine/repair shop that did the head milling said he had done it before and as long as none of the compound on the gasket had come off there wouldn't be any problem.  I did a search on the forum and a few people had done this and just reused the same gasket with no problems.  I want to start a survey here and see how many people have done this and what their results were.  Just post if you have done this on a ej series engine with the mls gaskets.  Post if it failed or succeeded, what engine and how many miles are on the engine after the reuse.

TIA

jelly man

Edited by jelly man

The torque sequence you follow is designed to crush the gasket in a very specific manner so that it seals. Once the gasket is crushed the first time its done and reusing it will not allow it to seal properly.

If this were a shim gasket for an exhaust header or the EGR valve, sure I reuse those all the time. But head gaskets are an entirely different beast, and cannot be reused once they've been removed, even if they haven't been run.

exhaust and EGR gaskets are not high pressure gaskets.   Head gaskets are, look at how thin the fire ring is.  you've got less than an 1/8th" of an inch and you are blowing exhaust into your coolant.   EJ25D already had an issue with that, and then the EJ251 had the external leak issue.. so you are already raising the risk of failure again.  Its not worth the hassle of having to redo a job because a 30 dollar gasket that is one time use didnt get replaced

I'd go with a new HG. Not worth the risk.

  • Author

Just noticed the replies to this topic.  Please excuse me.  I should have made it clear in the title also.  I don't know how to edit the title so I edited the original post to make it more plain.  I'm making a survey of those who have actually done this.  No more and no less.   I searched the board and only found a few mentions of those who had actually done this and no problems were mentioned.  Please just post only your own experiences with reused mls head gaskets that have been torqued, undone and retorqued once on an ej series engine without the engine being run.

again -- TIA

jelly man

Edited by jelly man

Why not just let everyone comment and read the comments?  Valid comments are still valid even if they aren't what you want to read or hear.  I highly doubt you are going to get great response rate on guys that did re-use them and know first hand how many miles are on the car now.  Additionally by MLS I assume 96-99 Ej25D head gaskets but those aren't the only ones that are that style.  The STI and the Turbo models sold beyond 2005 are MLS, the WRX is a MLS, etc.  These engines wouldn't necessarily be comparable since they aren't known for a high HG failure rate.  

I can certainly see your point but why would you delay your project for this one little mistake?  I would grab a new gasket and move onto the next job and sleep better knowing that your work isn't compromised by a gamble.  

you've got 3 guys with a combined 25,000 posts saying replace the head gasket.  

 

If someones done a hill billy rebuild and posted, I wouldn't take that as a legit answer. (Unless it was MilesFox, that guy can make anything work with nothing)

 

 You are asking if people are reusing a part not meant to be reused..  Its like taking a shower and putting dirty underwear and socks back on....

 

 Its like taking a shower and putting dirty underwear and socks back

on....

been there, done that.

Edited by johnceggleston

IMHO To me it would be worth the cost of the new head gasket just to be sure.

Did you do the final retorque?  or just the first torque before the 180 loosening, and then retightening.

 

I guess what I'm getting at, is these gaskets ARE designed to be crushed, loosened, and then recrushed under the final 90 + 90  more degrees tightening sequence.  So if you didn't finish the entire sequence......the gasket is still good.  If you completed the whole sequence........hmmmm? not sure if you could get it to seal properly again unless you torqued/crushed it even harder.

 

I am gonna say it's a gamble, but could work, at least for 10-50k miles.  Is it worth the risk?  that's up to the OP.

I`ve done it w/other motors than were run.Worked for me.

Would not recommend it though.

We live in a world of reuse anything you can on race / buggy engines reuse headgaskets lots and keep them stuck to heads when changing out burnt valves or teardown to crank keeping gaskets undisturbed to reuse them. Only on dont care motors but have don it lots last years race engine changed 4 pistons 1/3 the headgasket was reused 3 times and is still going even with nos and boost. Mind you i have my own surfacer so perfect surface every time. Have seen gaskets painted with aluminum paint and reinstalled i like avinnioc form a gasket seems to work best use it on every headgasket i do on anymake and no problems. But the quality of the used gasket whould be the varibble some come off perfect and some dont could only be reused if was good to begin with.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.