Valve Stem Seals

Well some of you have read my other thread about the blue smoke on the highway after a while of driving. Most people have said and I have concluded that this is probably the valve stem seals. I just replaced the 02 sensor which fixed my pgm-fi light problem, so now the only thing left to do is fix the smoke. I will probably buy a valve stem seal kit tomorrow, and tackle this job next weekend. I'm not going to be using an air compressor and tool, so I will probably feed a length of nylon rope through the spark plug hole. I have a question about this though. When I feed it through, will it come out the top or just touch, then when I turn it to tdc, will the valve hit the rope and the rope will make the valve stay up right? I know i need a valve spring compressor, but i will just rent one. I have feeler guages to reset clearances as well. Is there anything i need to know before tackling this job? Any tips?

You could probably get by with just an air tank if you wanted to go that route.
The rope trick works well, you want to practice maybe on a mason jar, lol. you have to get it crammed in just so so. It has to be tight enough to hold the valve closed and to keep it from falling, yet loose enough to get it out, yes you leave a little out. You may come out better buyng a whole engine gasket kit if you plan on keeping the car a while.
You can get the valve stem keepers out by just putting a good deep socket big enough to clear the valve stem but small enough to rest on the spring retainer, and pop it with a hammer, the keepers come right out. Putting them back in you need a "head on engine" valve spring compressor tool.

Leave the piston you are working on down a little. Take the rockers off. Feed as much rope as you can into the cylinder. After that turn the engine over till you feel the motor stop against the rope. Then you know the valve will stay up. When you are done, just turn the motor back and take out the rope. Don't forget to smack the valve with a soft hammer, to seat the keepers, after you have reassembled. Just make sure the piston is at BDC on that cylinder.

Remove all your spark plugs. Bring the piston to BDC your replacing the valve stem seal. Depending on how thick your nylon rope is, shove about 2 feet in. Rotate the crank sprocket until it stops. (don't crank down to hard) Use a OHC valve spring compressor to remove the keepers. Lightly lube the valve stem with oil before installing the seal. I use a rubber mallet to hit the valve to seat the keepers. So be careful with a steel hammer.

Also, replace your PCV valve. That will help if your valve guides are worn.

Alright well I guess im gonna tackle it this weekend. Any more tips?

When you have the springs off see if you have any side to side play in the valve guides by wiggling the valve stem from side to side. If there is much valve stem seals won't last very long. Just a little something I thought I would throw in.

I'd recommend using an adapter that threads into your spark plug hole allowing you to use air pressure to keep your valves shut, (rather than rope) if you have access to compressed air.

^Compressed air can be more dangerous Ive heard due to compression loss, power surges, etc.

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Originally Posted by mushroom_toy

^Compressed air can be more dangerous Ive heard due to compression loss, power surges, etc.

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:huh:
If you have that much compression loss, valve seals ain't gonna fix that blow by problem
Power surge? are you talking about loss of air pressure?

certainly the quickest way to get it done, using air, carefull you dont damage your threads though

the rope will get it done but pay close attention to what you are doing, also do not turn the motor with the starter, do not turn the motor backwards if you can help it.
If it becomes a big deal, look at the time you are going be using.. sometimes it may be better to just remove the head and freshen it all up anyway.. lap the valves, check the guides, new T-belt, clean out the carbon, inspect your cylinders, port and polish the head (that could take a couple of days) and take it to machine shop to resurface and wash.

Quote:

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Originally Posted by roodoo2

:huh:
If you have that much compression loss, valve seals ain't gonna fix that blow by problem
Power surge? are you talking about loss of air pressure?

certainly the quickest way to get it done, using air, carefull you dont damage your threads though

the rope will get it done but pay close attention to what you are doing, also do not turn the motor with the starter, do not turn the motor backwards if you can help it.
If it becomes a big deal, look at the time you are going be using.. sometimes it may be better to just remove the head and freshen it all up anyway.. lap the valves, check the guides, new T-belt, clean out the carbon, inspect your cylinders, port and polish the head (that could take a couple of days) and take it to machine shop to resurface and wash.

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I meant pressure loss with the air compressor. Not the engine. :)

Quote:

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Originally Posted by mushroom_toy

^Compressed air can be more dangerous Ive heard due to compression loss, power surges, etc.

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If your worried about that, use a leak down tester to allow regulated amount of pressurized air into the cylinders. (technically the right way for the job)
With just the springs out, you can check them for spring free length & squareness. You will need a dial indicator to measure valve guide wear. Without pulling the head, your limited on checks & a good inspection of valve train components.

http://ec1.images-amazon.com/images/...GL._AA280_.jpg

Compressed air is actually the easiest, safest and best method to use, aside from pulling the head. If you have a reliable source of compressed air and you ensure that the cylinder is at BDC it will work fine. You can shoot in some clean engine oil to help seal worn rings, and unless there are other major problems, using the air is the best way as far as I know.

Also, most compressors cycle between 125 and 150 psi, and you can regulate the pressure to whatever you want. Combustion pressure inside the cylinder is normally 5-700 psi, and compression alone is ~170, so I'm sure air from the compressor is not going to hurt it.

^Using the rope was the safest way as far as I can tell, there was no possible way to push the valves further than 1 cm when I had the rope stuffed into each chamber. It worked perfectly. As far as the smoke problem....I think its still there, still not sure yet.