Welcome to the North American Subaru Impreza Owners Club Tuesday September 2, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 01-30-2013, 11:49 AM   #1
ScoobyDrift
Scooby Newbie
 
Member#: 315446
Join Date: Apr 2012
Location: Trinidad
Vehicle:
2004 Impreza 2.5L

Default Turbo and SOHC Gaskets

Can a 2.5L Turbo Head Gasket work on a SOHC?
ScoobyDrift is offline   Reply With Quote
Old 01-30-2013, 01:51 PM   #2
chazly413
Scooby Specialist
 
Member#: 151079
Join Date: Jun 2007
Chapter/Region: MAIC
Location: College Park, MD
Vehicle:
2005 2.5RS RBP
motec system exhaust-RIP

Default

I believe it's the 05-07 STI headgasket that will work. It's something like that. Someone else more knowledgeable can correct me.
chazly413 is offline   Reply With Quote
Old 01-30-2013, 03:15 PM   #3
alt14
Scooby Specialist
 
Member#: 271928
Join Date: Jan 2011
Chapter/Region: Tri-State
Location: Gettysburg PA
Vehicle:
2014 WRX Limited
Crystal Black Silica

Default

I've seen people use sti gaskets as a replacement since they are thicker
alt14 is online now   Reply With Quote
Old 01-30-2013, 06:13 PM   #4
Storm
Scooby Guru
 
Member#: 5218
Join Date: Mar 2001
Chapter/Region: MWSOC
Location: SAUL'S Motorsports
Vehicle:
96L Most Over-
Developed Beater

Default

Quote:
Originally Posted by alt14 View Post
I've seen people use sti gaskets as a replacement since they are thicker
Except, they are thinner. 0.024"(or .027) versus a stock SOHC gasket thickness of 0.040".


Jay
Storm is offline   Reply With Quote
Old 01-30-2013, 06:26 PM   #5
alt14
Scooby Specialist
 
Member#: 271928
Join Date: Jan 2011
Chapter/Region: Tri-State
Location: Gettysburg PA
Vehicle:
2014 WRX Limited
Crystal Black Silica

Default

Hm.. I've always heard they were thicker and that's why people used them. I guess I misread, in that case it wouldn't it cause a failure sooner?

Last edited by alt14; 01-30-2013 at 06:33 PM.
alt14 is online now   Reply With Quote
Old 01-30-2013, 07:23 PM   #6
jamal
Scooby Guru
 
Member#: 71875
Join Date: Oct 2004
Location: Montana
Vehicle:
98 2.5GT
my wheels fit

Default

No, you would use them because they are MLS (multi-layer steel) compared to the stock garbage graphite coated gasket. The difference is pretty small. Part number is 11044AA642
jamal is offline   Reply With Quote
Old 01-30-2013, 08:35 PM   #7
alt14
Scooby Specialist
 
Member#: 271928
Join Date: Jan 2011
Chapter/Region: Tri-State
Location: Gettysburg PA
Vehicle:
2014 WRX Limited
Crystal Black Silica

Default

Ahh that's what it is haha thanks
alt14 is online now   Reply With Quote
Old 02-01-2013, 02:52 AM   #8
Bababou
Scooby Newbie
 
Member#: 280689
Join Date: Apr 2011
Chapter/Region: SWIC
Location: Glendale, Az
Vehicle:
2010 2.5i Impreza
Newport blue

Default

Does this carry over to newer n/a cars? Shoud I get a headgasket set for a 2010 STi for my 2010 2.5i?
Bababou is offline   Reply With Quote
Old 02-01-2013, 04:46 AM   #9
jamal
Scooby Guru
 
Member#: 71875
Join Date: Oct 2004
Location: Montana
Vehicle:
98 2.5GT
my wheels fit

Default

no. around 09 they started putting MLS gaskets in them. Also the cooling passages in the heads changed so the holes in the older 2.5 turbo gasket don't line up quite right. I think they use -770 which is the same as the 08+ sti.

And are the headgaskets on your 2010 leaking?
jamal is offline   Reply With Quote
Old 02-01-2013, 06:59 AM   #10
Marnix
Scooby Specialist
 
Member#: 51480
Join Date: Dec 2003
Chapter/Region: International
Location: The Netherlands
Vehicle:
1984 AM5, 1994 BC4,
2010 BR5

Default

All 2.5 gaskets you buy new from the dealer are MLS. Even for the 96-98 DOHC engines.

Up to 2006 all coolant passages for SOHC and DOHC 2.5L heads are the same, there are several gasket thicknesses available. After that the coolant pattern changed, therewith also the head gaskets.
Marnix is offline   Reply With Quote
Old 02-01-2013, 05:23 PM   #11
jamal
Scooby Guru
 
Member#: 71875
Join Date: Oct 2004
Location: Montana
Vehicle:
98 2.5GT
my wheels fit

Default

Quote:
Originally Posted by Marnix View Post
All 2.5 gaskets you buy new from the dealer are MLS. Even for the 96-98 DOHC engines.

Up to 2006 all coolant passages for SOHC and DOHC 2.5L heads are the same, there are several gasket thicknesses available. After that the coolant pattern changed, therewith also the head gaskets.
Last I checked that is not true, here in the US at least. The non turbo SOHC gaskets from about 99-09 are graphite coated ones. If you have one of those cars and go to the dealer for gaskets that's what you'll get, hence my recommendation to use the -642 turbo gasket. The DOHC phase 1 gaskets you get at the dealer are MLS (but thicker than the SOHC and turbo).

Quote:
Originally Posted by JohnM10 View Post
I will be getting my timing belt and valve cover gaskets (spark plugs seals are leaking) done later this year and may also get the clutch changed as well as the TOB is very noisiy. I am considering getting the head gaskets done at the same time to save on labor charges as well as to avoid having to have them replaced in the near future. At this time (97k mile) they are not leaking.
They are probably not going to since you have metal gaskets. Of course I can't gurantee that but it isn't something I would worry about changing. I have the worst car for headgaskets and am not worried since I put in the updated MLS parts.
jamal is offline   Reply With Quote
Old 02-04-2013, 01:30 PM   #12
Matt Monson
Scooby Guru
 
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
Vehicle:
99 2.5RS, '85 911
'73 914 and 2012 BRZ

Default

Quote:
Originally Posted by jamal View Post
Last I checked that is not true, here in the US at least. The non turbo SOHC gaskets from about 99-09 are graphite coated ones. If you have one of those cars and go to the dealer for gaskets that's what you'll get, hence my recommendation to use the -642 turbo gasket. The DOHC phase 1 gaskets you get at the dealer are MLS (but thicker than the SOHC and turbo).
Your dealer must be selling outdated stock. I haven't seen anything but MLS gaskets at my dealership for a few years now. Pretty sure even the SOHC Ej25 gasket was changed to MLS on one of the several updates over the years.
Matt Monson is offline   Reply With Quote
Old 02-01-2013, 07:58 AM   #13
Bababou
Scooby Newbie
 
Member#: 280689
Join Date: Apr 2011
Chapter/Region: SWIC
Location: Glendale, Az
Vehicle:
2010 2.5i Impreza
Newport blue

Default

Ok so would OEM be a good choice or should I go with something else? They are not leaking yet but I am at 71k and planning to do the timing belt kit in the next couple months and I have been seeing alot of these failing around 100K so since I'm going to be getting into the car anyways figure might as well make a weekend of it. Planning on a light weight crank pully and all new belts and hoses while I'm at it.

Last edited by Bababou; 02-01-2013 at 08:21 AM.
Bababou is offline   Reply With Quote
Old 02-01-2013, 08:09 AM   #14
alt14
Scooby Specialist
 
Member#: 271928
Join Date: Jan 2011
Chapter/Region: Tri-State
Location: Gettysburg PA
Vehicle:
2014 WRX Limited
Crystal Black Silica

Default

I think what he was asking was your 2010 is leaking.. meaning after a certain year, yours included they started using the mls gaskets and the chance of them failing is lessened.
alt14 is online now   Reply With Quote
Old 02-01-2013, 08:36 AM   #15
Bababou
Scooby Newbie
 
Member#: 280689
Join Date: Apr 2011
Chapter/Region: SWIC
Location: Glendale, Az
Vehicle:
2010 2.5i Impreza
Newport blue

Default

I see so save the headache and extra cash and just watch it to see what happens and deal with it when it shows signs of a problem.
Bababou is offline   Reply With Quote
Old 02-01-2013, 11:21 AM   #16
Marnix
Scooby Specialist
 
Member#: 51480
Join Date: Dec 2003
Chapter/Region: International
Location: The Netherlands
Vehicle:
1984 AM5, 1994 BC4,
2010 BR5

Default

It's better to replace it as a precaution than to wait and see until it happens. Then you need to deck the block (that's where the problem has it's root cause).
Marnix is offline   Reply With Quote
Old 02-01-2013, 12:19 PM   #17
JohnM10
Scooby Newbie
 
Member#: 244231
Join Date: Apr 2010
Chapter/Region: NESIC
Location: Providence, RI, USA
Vehicle:
2006 Impreza 2.5i 5M
Crystal Grey Metallic

Default

I will be getting my timing belt and valve cover gaskets (spark plugs seals are leaking) done later this year and may also get the clutch changed as well as the TOB is very noisiy. I am considering getting the head gaskets done at the same time to save on labor charges as well as to avoid having to have them replaced in the near future. At this time (97k mile) they are not leaking.
JohnM10 is online now   Reply With Quote
Old 02-02-2013, 02:20 PM   #18
Sir-Knight
Scooby Specialist
 
Member#: 73636
Join Date: Nov 2004
Chapter/Region: E. Canada
Location: the 'wa, ontario, canada
Vehicle:
2007 Impreza 2.5i SE
newport blue pearl

Default

because I just asked my mechanic since I'm booked for wednesday to have this done, apparently all the gaskets according to him, are graphite, (for 2.5rs/i) the only mls ones are the STI gaskets, and these are factory parts from the dealer.

I told him I'd eat the extra cost of having heads machined so I can switch to the sti gasket. We'll see how that goes.
Sir-Knight is offline   Reply With Quote
Old 02-03-2013, 12:51 AM   #19
Storm
Scooby Guru
 
Member#: 5218
Join Date: Mar 2001
Chapter/Region: MWSOC
Location: SAUL'S Motorsports
Vehicle:
96L Most Over-
Developed Beater

Default

Call Cometic and get a set of their gaskets. You won't be sorry.


Jay
Storm is offline   Reply With Quote
Old 02-04-2013, 02:30 PM   #20
jamal
Scooby Guru
 
Member#: 71875
Join Date: Oct 2004
Location: Montana
Vehicle:
98 2.5GT
my wheels fit

Default

I don't think so. Someone I know just got a gasket kit for their 02RS and it came with the old gaskets, and the online parts dealers still list 11044AA633, which looks like this:

jamal is offline   Reply With Quote
Old 02-05-2013, 01:03 PM   #21
Bluefoton
Scooby Specialist
 
Member#: 141373
Join Date: Feb 2007
Chapter/Region: E. Canada
Location: Quebec, QC
Vehicle:
2008 2.5i-hatch -
now with a HID retrofit

Default

I'll side with Jamal on this one. As far as i know:

The EJ251 and the EJ253 use by default the 11044AA633. Single layered steel.

EJ251 owners sometimes replaced their HG with the 11044AA642, MLS, used in the 04-05 EJ255 and 04-06 EJ257.

Now, for some reason I read that EJ253s can use the 11044AA670, itself used in the 06-08 EJ255. Can't confirm that though.

To add to the confusion, there is also the 11044AA770, used in the EJ257 2008+ - although it appears to look the same as the 670.
Bluefoton is offline   Reply With Quote
Old 02-05-2013, 01:09 PM   #22
jamal
Scooby Guru
 
Member#: 71875
Join Date: Oct 2004
Location: Montana
Vehicle:
98 2.5GT
my wheels fit

Default

670 and 770 are the same thickness and construction, but the 670 is specifically for the 07 sti and then the 770 is on the 08+ and new n/a 2.5s. The difference is the cutouts for the cooling passages in the head. I think I have pictures of everything around somewhere.

Last edited by jamal; 02-05-2013 at 02:05 PM.
jamal is offline   Reply With Quote
Old 02-06-2013, 12:20 AM   #23
Bluefoton
Scooby Specialist
 
Member#: 141373
Join Date: Feb 2007
Chapter/Region: E. Canada
Location: Quebec, QC
Vehicle:
2008 2.5i-hatch -
now with a HID retrofit

Default

it'd be nice to clear that up once and for all. So 642s for EJ251 and 770 for EJ253? Is there any difference in between coolant passages on the head in these two N/A engines?
Bluefoton is offline   Reply With Quote
Old 02-07-2013, 01:27 AM   #24
jamal
Scooby Guru
 
Member#: 71875
Join Date: Oct 2004
Location: Montana
Vehicle:
98 2.5GT
my wheels fit

Default

Quote:
Originally Posted by Bluefoton View Post
it'd be nice to clear that up once and for all. So 642s for EJ251 and 770 for EJ253? Is there any difference in between coolant passages on the head in these two N/A engines?
Phase 1 dohc is -610, which is a thicker MLS gasket
Phase 2 sohc to somewhere around 08-09 should use -642, which is the 04-06 turbo gasket. So that includes the 251 and 253 I think.
09 ish and up already have the -770 MLS gasket in them, which is the same thickness as 642 but has different cooling passages.

I think the change was whenever they started putting avcs or avls or whatever it is on the n/a 2.5s.
jamal is offline   Reply With Quote
Old 02-12-2013, 10:30 PM   #25
cdwahl
Scooby Newbie
 
Member#: 144605
Join Date: Mar 2007
Chapter/Region: BAIC
Vehicle:
2007 2.5i Wagon
Satin White Pearl

Default

Quote:
Originally Posted by jamal View Post
Phase 1 dohc is -610, which is a thicker MLS gasket
Phase 2 sohc to somewhere around 08-09 should use -642, which is the 04-06 turbo gasket. So that includes the 251 and 253 I think.
09 ish and up already have the -770 MLS gasket in them, which is the same thickness as 642 but has different cooling passages.

I think the change was whenever they started putting avcs or avls or whatever it is on the n/a 2.5s.
What about for valve cover gaskets, will the dealer have MLS?

I need to replace my valve cover gaskets and I am not excited to install the same ones that failed after 60-90k...

Last edited by cdwahl; 02-12-2013 at 10:31 PM. Reason: typos...
cdwahl is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 11:15 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.