Valve Seals Without Timing Belt Replacement - 4.7L

Hi all - first post. I have a very good friend with a 2005 Tundra V8. I end up doing a lot of work for/with him on the truck -- mainly because I have a lift and many, many tools.

He came to me asking if we could do the valve seals -- I've done valve seals many times but mostly on domestic stuff and never on overhead cams (though I have changed timing belts on OHC vehicles).

So my question is -- do we treat this as a full blown timing belt change (new water pump, pulleys, tensioner, etc), or if that has been very recently done, can we just take the front of the engine down to where I can get to the timing belt tensioner, remove that to have enough slack to remove the belt and cams to get to the valve seals? And then go through the normal cam replacement process?

Thanks in advance.

 

The 05 will be pretty involved with it's DOHC VVTi setup. I'm always of the opinion that if some other clown can do the work then this clown could probably do it as well. Researching the procedure and having the proper FSM and tools and parts to do the job before breaking it down is a must for me. If it were me and I was getting that deep in, I would do the full timing belt, water pump, tensioners, serpentine belt, possibly radiator, fan bearing and additional Fluids and filters.

 

I would step back and ask why you are doing valve seals? I've never heard of doing valve seals in these motors unless you are doing a full rebuild. These motors are not known for problematic valve seals, say like 90s Mitsubishi V6s that ate valve guide seals for lunch every 75k miles.

I concur if you are going to be in there do it all unless it's been done in the last 40K miles already...consider a radiator as well if it's original.

 

Do you mean valve cover gaskets? Those will weep over time and are pretty easy to replace.

 

you have to remove the belt. but if its a new enough belt and you make marks on it BEFORE removal (WITH AN ARROW POINTED TOWARD THE FRONT OF THE ENGINE, orientation matters when going off the marks!) . you can reuse it. you will need a valve seal remover to get the seals off since they sit in pockets where the buckets live. Lisel makes a good tool i use. When replacing the exhaust seals are a different color from the intake seals.

 

thanks all - he informed me that he has about 100k on the current belt. So going to help him do that. Would be nice to not have to pull the cams for the valve seals and just tackle it as a straight up timing belt job. The cylinder 8 plug was oily - the rest looked fine. He says he gets white smoke at startup (I said, 'no big deal') and he also says it chugs and shakes going uphill. I guess his research on white smoke pointed him to valve seals and perhaps he is relating the two. Any advice to talk him off the 'remove the cams for the valve seals' ledge? I think that is a path we don't need to go down.

I think he said, about 150k miles on the truck and he bought it at 50k. Has no specific recollection of having a timing belt done but is checking his records.

 

If not steam from condensate, white exhaust smoke is usually coolant burning. Oil smoke will have a blue tint to it.

Oily #8 plug only says it's not firing (chugs and shakes?). I would be sure of the diagnosis. Sounds like he needs to spend some money, but I would be sure the money is going to the right location.