I've got a '99 OBW with the 25D - engine was replaced with a "120k used engine" is all the reciept I have says. The gaskets are MLS style but I'm not "up" on how to tell if they have been replaced or not. It seems to run just fine - no overheating issues - came to be my new project because of a grenaded 5 speed.

 

So what am I looking for? If it's already got the upgraded gaskets I'm not going to replace them again. If it doesn't then I want to do them up front before I sell it since I know it's a problem with these. Problem I have is although I have all the documentation on the car, the engine could have had the HG's changed in the 120k before it was in this car . So now I have to do some investigating.

 

I did some searches but this topic has been talked about 3 times a week for a decade and wading through all that crap is more than I can stand when half the (possibly applicable) threads I've found have dead links and bad picture URL's

 

Anyone help a guy out here?

 

*edit* - did more searching and still can't find a definite answer. I saw at least one post where somone said the number of layers increased from 3 to 4 somewhere in the design change path but the post was like 6 years old.... this one has 4 layer gaskets in it. That help any?

 

GD

Edited August 10, 201015 yr by GeneralDisorder

i was able to identify new gaskets on my 97 obw which i bought with 98k miles.

 

if you compare pictures, or actual gaskets side by side you will see they have slight differences which you MAY be able to identify with out removing the heads. i looked for the rectangular "stamp" or imprint in the corner of the new gaskets. the old ones do not have them.

 

the other thing to look for is the "tabs" that hang out in the exhaust port area, the new are larger.

 

 

i referred to these pics. the new on the left has different corners (the corners closet to the old gasket) and the tabs at the exhaust ports.

 

 

 

of course if they were change a while ago you may not be able to see the difference.

Edited August 10, 201015 yr by johnceggleston

nice pics john. the new style are a multi layer design right, is that what it's called?

 

the older/original style seem like EA82 gaskets - just one solid piece of material. is that true or is that just an artifact of age making it look like that when i remove them?

 

i saved one of the last ones i took apart to take a picture though i'm not sure i could get any detail with it.

 

if you see a multi later set up, i'd think that's a new gasket. but they do start rusting, getting dirty, aging, and it's hard to tell sometimes. there were plenty of failures at all sorts of low mileages too - 30,000...etc, so it's possible they were replaced any time in the past 10 years.

In this case the edges of the gaskets are clearly visible and are clearly MLS (Multi-Layer-Shim) gaskets. I count 4 layers.

 

So are the orginal EJ25D factory gaskets corrugated graphite style like an EJ22 gasket? Is that what I'm seeing? It's hard to tell from the picture. I've installed the MLS gaskets before but I've yet to remove one so I'm not that familar with what a used one would look like

 

Also - did Subaru ever roll any of the newer gaskets into the production runs?

 

I'm going to check for those edges sticking out farther in the exhaust port area. That seems like a good indicator.

 

My concern is that they redesigned the gaskets multiple times and since they could have been replaced at any time in the past.... how could I tell if I have the latest gasket or one that's only the first or second redesign? Or were the MLS gaskets the last design and all previous were graphite?

 

GD

Edited August 10, 201015 yr by GeneralDisorder

In this case the edges of the gaskets are clearly visible and are clearly MLS (Multi-Layer-Shim) gaskets. I count 4 layers.

 

So are the orginal EJ25D factory gaskets corrugated graphite style like an EJ22 gasket? Is that what I'm seeing? It's hard to tell from the picture. I've installed the MLS gaskets before but I've yet to remove one so I'm not that familar with what a used one would look like

 

Also - did Subaru ever roll any of the newer gaskets into the production runs?

 

I'm going to check for those edges sticking out farther in the exhaust port area. That seems like a good indicator.

 

My concern is that they redesigned the gaskets multiple times and since they could have been replaced at any time in the past.... how could I tell if I have the latest gasket or one that's only the first or second redesign? Or were the MLS gaskets the last design and all previous were graphite?

 

GD

 

I was reading up on Frankenmotors and saw some discussion about this. Subaru switched to MLS prior to the latest revision, so seeing that it's MLS does not guarantee that it's the latest and greatest. However, I have no idea how substantial the changes were after they switched to MLS. It could just be different part numbers...

 

Jacob