Toyota OEM 16V 4AGE Valve Stem Seals...

[jondee86]

I received eight each of these in a gasket set for a smallport 4AGE...



However, they are not identified as intake or exhaust side seals, and they are
different, so I am wondering if anyone knows for sure which is which ?

The ones on the left are black inside with a fat lip at the open end, and the ones
on the right are grey inside with shallow ridges inside. If I was a guessing man,
I would say the black ones go on the intake side, but I would like to be sure.

Cheers... jondee86

[sergei]

I know wrong engine but:

http://www.tcorolla.net/overhaul-1047.html

I think with that extra O-ring you will not be able to fit them wrong.

[jondee86]

Seems I guessed wrong Further extensive research brings up a mass of conflicting
opinion. But sifting the wheat from the chaff, the balance of probabilities does tend to
indicate that the "bronze" shell with the grey seal goes on the intake, and the "silver"
shell with the black seal goes on the exhaust.

And if that isn't enough to get you on the edge of your seat, then how about my discovery
that I had picked out the only black seal of the set that had a tiny o-ring lodged inside
Seems while rolling around loose inside the gasket set it picked up one of the o-rings that
were also loose, and I just assumed it was part of the seal and meant to be there. It wasn't
until I happened to look at the others, that I realised what had happened !! So now it is
obvious that all the seals are the same design, the only difference is the colour and seal
material.

Don't you just love it when shit like that happens

Cheers... jondee86

[GDII]

That's crazy. The hiding o ring of confusion.
I bought a set of 4AGE/3SGE valve seals for my GEN2 3SGE and they were all the same, not OEM but still worked. When I saw the '2' types of seals in your picture I was a bit confused to why it was so different. Seeing as I have never done any 4AGE work I thought I wouldn't say anything until it was answered. If that o ring was part of the seal then the valve bush would be very thin or the valve itself would be tiny.

Glad you figured it out. I think the different OEM seal types are for heat differences due to the exhaust valve being hotter and the intake being cooler because of the air fuel mixture passing over it during the intake stroke.

[jondee86]

Yeah, what I did discover while researching this question, is that some aftermarket
seals use the same material (presumed to be Viton or similar high temp stuff) for both
inlet and exhaust seals. Others, like Supertech, use stronger colours to differentiate...



It is a bit interesting that Toyota chooses to use different materials. It is difficult to
imagine that the cost saving of using two different materials is significant, when you
take into account the extra work in maintaining separate inventory. So I am inclined
to think that they use two different materials; one best for the inlet valve operating
conditions, and one best for the exhaust valve.

Another one of those questions about which it would be nice to know the truth, but
to which we will never know the real answer

Cheers... jondee86

[GDII]

I bought some from STA parts, they were all brown but I don't think the manufacturer of them makes blue ones. They fit 4A, 3S, 2E and some Mazda engine too.

[sergei]

Technically IMO, The inlet seal should have different sealing surface to exhaust seal, simply because it might see some vacuum. The material difference also due to temperature range the valve stems are at. High temperature seal might not work well in low temperature conditions, and low temperature seal might not last as long in hot temperature.