I had to get a safety check for my 99 Camry at the shop I go to and while I was there, inquired about getting the valve stem seals replaced since the engine will emit blue smoke on startup when cold. He recommended to live with it as long as the plugs weren't fouling. He did say that when you do replace the stem seals, that the valve guides have to be checked and replaced if worn since worn guides would damage the new seals. Just passing along some info.
david
If you are using 5W-30 or 0W-30 oil, switch to 10W-30. That will substantially reduce the smoking.
If you dont burn oil , consume alot, dont worry, its normal and actualy lubricates the cilinders when they need it most, on a dry startup.
I would try some that high mileage motor oil. I heard that Lucas Oil Additive works well and will also slow or stop oil consumption. There are other oil additives that may work as well. Make sure the container mentions it will help oil seals. I understand these type of products can soften all the seals.
Thanks for the suggestion, I'll switch to a higher viscosity oil. I've never seen 0 weight oil before - you must be way up north. :-)
david
It seems that it would be helpful on reducing cylinder/ring wear. Maybe not so good for the cylinder head though.
david
I'm a little worried that oil additives that suppress oil consumption may aggravate the oil-coking problems in these 4-cylinder engines. Would this be a reasonable assumption?
david
Sounds reasonable given the labor cost. Try out the high mileage oil first, these have o-ring conditioners to swell and help seal.
If the valve stem clearance is off by that much then you're right it's probably not worth doing the seal alone -- the cylinder head should be serviced if not the lower half of the engine too. I think the valve guides are about $2 a piece, but labor cost and other gaskets add up. Hopefully the wear is minimal with regular 3000-mile oil changes and a decent filter (Bosch Filtech or Purolator PureOne).
For those who do their own timing belt job and are up to it, consider the stem seals every other belt change -- it adds about $30 for the Fel-Pro stem seal set and $12 for the Fel-Pro valve cover set.
That's another reason I always use the thickest oil approved for the temperature range from the beginning. Thicker oils seal better and have stronger oil films but do flow less than thinner oils.
0W-20 are spec'ed for newer cars for their tighter oil clearances and better mileage rating, don't think 99 uses it but your region may vary.
I like that - it isn't a failure, it is a feature!
Ed
I have heard that it's a good idea to replace the water pump when the timing belt is serviced but not the valve stem seals. Is the reasoning for this is that it's easy to remove the head at this time?
david
consider>> the stem seals every other belt change -- it adds about $30 for the>> Fel-Pro stem seal set and $12 for the Fel-Pro valve cover set.
when the
reasoning
You do NOT need to remove the head for the stem seals. You DO need to remove it for the valve guides. dc
You don't have to remove the cylinder head to get to the stem seals. But I can understand why some techs don't want to do this. You'll have to take off the valve cover, remove the cam shafts carefully following directions (because of small thrust clearance), remove the 16 valve springs and then pull off the stem seals.
People usually replace the water pump, camshaft seal, oil pump seal, and front crankshaft seal etc while doing the timing job (see my list below). Why? Because that section of the engine is already taken apart to get to the belt, and the labor to get to them again is much more than a $5-8 seal or a pump. However, you have to take off more parts to get to the stem seals, so I understand why some techs don't want to bother.
We were talking about having a shop do the seals. So they do need a lever type valve spring compressor (e.g., SP91400A) without taking the cylinder head off. But decent shops should have them, and your local parts stores may (or may not) have a free loaner of the lever type of valve spring compressor (most have OHV and C-clamp types) for the home gamers.
Valve stem to guide clearance is about 1-2.5 mils, with max specified just under 4 mils. How that's going to adversely affect a new stem seal is kinda beyond me, seriously.
Parts I'd replace duirng a timing belt job: (older
Absolutely!
To remove valve springs with the cylinder head on, a lever type spring compressor is used, like the Schley SP91400A.
If the cylinder head is removed, then use:
Stem seals aren't necessary at every timing belt change. But as I said you can consider them every 2 (or even 3) timing belts if you even want to change them. That said, Toyota stem seals are known to cause the start-up blues, but there are other causes of oil leaks.
Toyota engines cook the oil so much that in 2004 they reduced the 7500- mile oil change interval down to 5000 miles. Let's just say that I would not be surprised if your stem seals got cooked too, even if they are made of DuPont Viton fluoroelastomer good to 400 degF (the cheaper intake seals mean they probably aren't). ;)
Thanks for the info. To tell the truth, I have no idea about what's under those valve covers. My previous OHC engines that I worked on (Fiat and VW Rabbit) had the valves springs under shim-adjusted cam buckets that required the cylinders be pressurized to allow the release of the spring retainers. How are the valve springs held in place in the Toyota engine? Thanks.
david
Same as some VW setup like you described. So maybe you can do the seals on this engine too! :)
Good luck!
The valve shim pictures aren't very clear, but Fig 30, 35, 47 on the free online repair guide. Click to enlarge:
For those who are interested, besides the good 'ol rope-in-the- cylinder trick for on-engine stem seal replacement, these preferred tools may help in holding the valves:
They do say something like 50% of engine wear is on startup from no oil in the cilinders, I know at 110000 on mine it passed the EPA tests where the motor might go to 3-400000 judging by the polutants I put out to where it is considered a poluter. But the body wont make it. My plugs burn clean, I consume no oil, so I figure its lubed when it needs it, on startup. Figure it as 2 stoke gas on startup, actualy I start my big generator for testing on 2 stroke with maybe a cup of gas. If I dont I can hear the valves clack till the pump get oil to the top, in winter with thick old oil I imagine the damage can go on for 5 seconds or more. Let it smoke on startup, maybe thats why the motors last so long.
That's interesting. I had several 1972 Fiat 124 coupes in the 80's. The VW and Volvo OHC engines of the time used the same shim sets and paid fees to use Fiat's very simple and direct method of valve operation. Fiat's method of rear disk parking brake actuation sure looks similar to the system we use today. These cars came out in 1967! While 4 wheel disk brakes and 5-speed transmissions and belt driven DOHC engines are pretty standard today, back then, they were very cool features.
david
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