As I understand, there were three iterations of this part - the plastic, aluminium and steel.

 

My car had 11831AA150 put in in 2007, is that the plastic, steel or aluminium part?

 

Is new steel part susceptible to leaking?

 

Thanks

I don't know which one you have:

 

Aluminum is best, IMHO as it expands as the same rate as the engine.

Steel and Plastic are both going to move at slightly different rates to the engine block.

 

All 3 are OK if they are pulled, cleaned and resealed with quality RTV and the screws put in will lock-tight.

There are three part numbers identified here:

 

http://opposedforces.com/parts/legacy/us_b11/type_45/engine/cylinder_block/illustration_1/

 

In order they list the following P/N's:

 

11831AA080 (Plastic)

11831AA150

11831AA210

 

The last part number is the only currently offered for sale by Subaru Dealers.

 

From this photo of the 210 it looks like steel:

 

 

I would say you do not have the plastic one installed. I don't remember if the aluminum one came before or after the plastic one.

I don't know which one you have:

 

Aluminum is best, IMHO as it expands as the same rate as the engine.

Steel and Plastic are both going to move at slightly different rates to the engine block.

 

All 3 are OK if they are pulled, cleaned and resealed with quality RTV and the screws put in will lock-tight.

 

The steel one is the latest revision, and said to be the best. That's what I'm getting for my EJ22 swap engine. It currently has the aluminum one, but for such a cheap part, why risk pulling the engine again?

 

All three are NOT ok, the plastic ones crack. That's not good. Don't re-use a plastic one.

Edited February 1, 201115 yr by 987687