This week I sent my valve cover to Justin at Detective Coatings. He did a great job with the powdercoat, but I'll discuss that in another thread. The reason for this thread is that I found out the hard way that it's very easy to end up with the wrong valve cover gaskets for your particular Evo, resulting in more downtime than you anticipated.

Lesson #1 - Evo 8 and Evo 9 have different valve cover gaskets - they are NOT interchangeable

Everyone knows this one, right? Well I didn't.

I read more than a few threads before deciding to send my valve cover to be coated. Everyone mentions getting a new gasket. I never read one post of caution about the 8 and 9 gaskets being different. Most misleading of all is the official Evo part number thread.

https://www.evolutionm.net/forums/ev...-here-211.html

Ctrl+f "valve cover" and this comes up right away:

MD340535 valve cover gasket

Doesn't specify Evo 8 or 9 and valve cover gasket only shows up once in the list. So that's what I ordered. Well it turns out that's the 8 valve cover gasket and my car is a 9. So no Evo until the dealership opens Monday. I'm about to post in that thread to have it corrected so no one else ends up buying the wrong part like I did. Here is how they should be listed

MD340535 valve cover gasket Evo 8
MD372906 valve cover gasket Evo 9

Lesson #2 - You're supposed to replace the spark plug ring gaskets in addition to the valve cover gasket

Every thread mentions getting a new valve cover gasket. Few, if any, mention the spark plug gaskets. Actually, if you google "Evo spark plug gasket", one of the first threads that comes up is this one.

https://www.evolutionm.net/forums/ev...ug-gasket.html

The second post in that thread says "There is no such thing as a spark plug gasket. Are you refering to the valve cover gasket?" This, as I now know, is wrong. But it just goes to show how many people are unaware of the spark plug gaskets.

Making things even more confusing is that apparently the spark plug gaskets for Evo 8 and 9 also have different part numbers. I found this out from Amazon, where they are sold by AWD Motorsports, and confirmed on Mitsubishi parts website.

MD186785 spark plug ring gasket Evo 8
MD373583 spark plug ring gasket Evo 9

Today I went to the Mitsubishi dealership and bought 4 of MD186785 because that's the only part number I found in one of the few threads on the topic. The girl in the parts department actually asked for my VIN to make sure I was getting the right ones. I told her I was sure because the forum is never wrong . Went right home and fit them in the valve cover. They seem to fit fine but now I'm worried I got the wrong part again.

http://www.streettunedmotorsports.co...er_gaskets.htm

On STM's website, it seems like they sell the same spark plug ring gaskets for both Evo 8 and 9. So I could be wrong about them being different. Hoping someone can clear this one up for me.

 

Im hoping to bring this thread back for all the peeps purchasing evo’s to this day. I’m running into this issue and I’m glad you mentioned the spark plug gaskets. Definitely saved me some downtime

 

JDM VII valve cover came with OE gaskets and works just fine on an 8 head