2002 4.7 valve seal job?

Hello everyone,

my name is Pete and I’m new to Toyota. The last forum I was on was when I bought my first mustang 15 years ago.

I’d like to thank you all in advance for taking the time to read my post.

I have a 2002 4.7 that I bought to fix up because I thought the issue was just fuel injectors but when the white smoke cleared, then came the blue. I’ve done a lot of reading and have come to believe it’s a bad valve seal in cylinder 8. I have a flashing cel with a p0308. When I bought it, it was misfiring on three cylinders and a random misfire but they all cleared after the new injectors except for p0308.
The spark plug is oil crusted so I’m 99% sure it’s a valve seal.

With that being said, is there a good way to change the valve seals with the motor in the car? Would it be easier to take the head off the block? What puts me off doing this job the most is my fear of screwing up the timing (timing belt and water pump were done 50k ago). Does anyone have any good tips on how to do this? I have seen the post of lextreme.com and that helped quite a bit.

Any help will be greatly appreciated. I’m very happy to be here, I have wanted to be a Yota dude for a long time!

 

https://www.youtube.com/watch?app=desktop&v=ICvuZcmaccI

 

I have taken the heads off my truck a couple of times and looking to do so here in the future that might be easier and it wouldn't hurt to have both heads gone through by a professional if you loosen the retainers for the valves they can possibly fall in to the cylinder. Also valve adjustment is done by shims so sending your head to a professional to redo the seals you'll have all new seals and he'll have your valves adjusted but that's just my vote