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- - Exhaust Valve Stem Seals Leaking Oil (https://www.ft86club.com/forums/showthread.php?t=133305)

Exhaust Valve Stem Seals Leaking Oil

Hi everyone,

Like the title states, the #3 cylinder (passenger side rear) exhaust valve stem seals allowed oil to leak into my exhaust system creating a ton of smoke when the car was under load and accelerating from a stop.

At the time the problem began, mods included a JDL turbo kit, Verus AOS, and a JDL oil cooler.

I was speaking in past tense because my engine is now getting built with forged bottom end components and Supertech valve springs since the engine needed to be removed in order to fix the valve stem seal leak anyway. I’m also changing the AOS to Radium’s dual catch can.

The reason for this post is because the mechanic that’s doing the engine work stated that he believes it’s a common issue with the FA20 motors. He said that a WRX came into his shop with the same issue...

Has anyone else had this problem? This rebuild has obviously taken a hit to my wallet and a little worried that the problem will surface again in the future..Any responses are greatly appreciated!

I haven't read anything on this forum about bad valve stem seals. - :iono:

humfrz

Exhaust Valve Stem Seals Leaking Oil

Yeah I haven’t seen anything either but wanted to throw the question out to the community anyway...

Does anyone know what usually causes valve stem seals to go bad in the first place?

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Usually with high mileage 5SFE had that issue. Certainly not a very common problem with toyota engines.

Quote:

Originally Posted by Muaddib (Post 3193142)

Usually with high mileage 5SFE had that issue. Certainly not a very common problem with toyota engines.

You mean Subaru engines.

I have the same issue

Quote:

Originally Posted by kimcheefists (Post 3192923)

Hi everyone,

Like the title states, the #3 cylinder (passenger side rear) exhaust valve stem seals allowed oil to leak into my exhaust system creating a ton of smoke when the car was under load and accelerating from a stop.

At the time the problem began, mods included a JDL turbo kit, Verus AOS, and a JDL oil cooler.

I was speaking in past tense because my engine is now getting built with forged bottom end components and Supertech valve springs since the engine needed to be removed in order to fix the valve stem seal leak anyway. IÂ’m also changing the AOS to RadiumÂ’s dual catch can.

The reason for this post is because the mechanic thatÂ’s doing the engine work stated that he believes itÂ’s a common issue with the FA20 motors. He said that a WRX came into his shop with the same issue...

Has anyone else had this problem? This rebuild has obviously taken a hit to my wallet and a little worried that the problem will surface again in the future..Any responses are greatly appreciated!

I am having the same issue where my cyl 3 plug gets fouled by a lot of carbon build up. I am boosted. Burns oil when under load.

I'd look at rings before valve stem seals on this engine. Especially boosted.

Exhaust valve stem seals leak under vacuum. Need a leak down done.

Exactly. Boost would be pushing back into the head under load.

I'll bet the #3 piston ring land is cracked....and it's not a spring issue....

I wouldn’t rule out something simple like a bad PCV yet, but fouling number 3 all the time is not promising.

Comp test
Leak down test.

Everything else until then is just guessing.

Outfront Motorsports suggested including new valve guides when I was shopping for a built short block. They stated the guides are often troublesome eventually.