Did Subaru improve its head gaskets?

[alaskanjer]

I think I remember reading somewhere on this site that part of the reason for the head gasket troubles for the DOHC 2.5 engines was that the original OEM HGs were not up to the job. Once Subaru noticed the problem, they improved the head gasket. The improved head gasket still doesn't have a perfect track record, but they have been a lot more reliable than the originals.

 

Now when I search I am not finding any posts to that effect.

 

Did Subaru change their HGs for that application, or did I invent that idea in my head? (Or more likely, misinterpret a comparison between the DOHC engines and the SOHC, or maybe OEM head gaskets vs. something else?)

[86subaru]

not sure about hg , i delivery at the plant where they are made, i asked a few people there, they suggested changing the coolant more often, than what the manual said,

[idosubaru]

there's quite a few variables involved as you've sort of gleaned yourself.

 

DOHC - Subaru has the 610 (last 3 digits) headgasket for those that's a nice MLS gasket, which i have used on SOHC heads as well. i'm a fan of that gasket and know the local subaru shop uses them all the time.

 

SOHC - these gaskets suck from what i've seen, but i'm not a gasket expert. folks are using one of the turbo gaskets i believe...ends in part number 642 i think (from memory).

 

there are quite a few gasket numbers and supercessions, etc. for DOHC - the 610 is definitely the way to go - for SOHC it varies. i would research those a bit and opt for the turbo gasket folks are recommending or see if that 610 gasket will work - it's very thick MLS and will decrease compression a bit but i'd rather have the better gasket. the one i used on a SOHC vehicle seemed to do just fine, i noticed no performance difference or loss of 8 hp.

[GeneralDisorder]

DOHC gaskets were redesigned 4 times. The latest gasket is an MLS turbo-style gasket and is quite good.

 

They have also redesigned the SOHC gaskets at least once. To correct a problem with the sealant washing away from the gasket and causing external leakage of coolant and oil - primarily on the driver's side head. I have personally replaced gaskets as new as '06 with external oil leakage.

 

GD

[alaskanjer]

Thanks for the replies.

 

Do you know about when they improved them?

 

The reason I ask is because I have a 98 OB that got a new engine (shortblock) under warranty from the dealer in late 2002. The warrantied engine now has almost 150,000 on it. The HG are fine right now, but if there is a high likelihood that they will go soon, I'd rather do it now as I have some time and help.

 

FWIW, I have the paperwork from the warranty transaction. It lists:

gasket seal kit part # 10105AA401. I don't know if the HG can be identified when it comes as part of a kit.

[afterbang]

you can actually see if they are one of the MLS HGs by looking at where the head meets the engine block. It's easier to see on the drivers side. The HG sticks out and you can actually see the separate layers of the gasket. The old ones are not layered.

[idosubaru]

alaskanjer said:

It lists:

gasket seal kit part # 10105AA401. I don't know if the HG can be identified when it comes as part of a kit.

looks like you might be in luck - i found this listing for part numbers included in the overhaul kit you posted and it lists the head gasket part number as:

 

11044AA610

 

that was from a skip who did his in August of 2003 and bought this same kit. so unless the part number was superseded at some point it looks like you might have a desirable HG in there!?

 

like previously mentioned you can easily tell these headgaskets by looking at where the HG extends externally, simple visual inspection under the hood.

 

Edited December 24, 2020 by idosubaru

[Caboobaroo]

I work for an independent Subaru repair shop in Seattle and we sell complete headgasket kits for all Subarus. Check out http://WWW.allwheeldriveauto.com for details