Help! Changing Springs, Air Compressor Method doesn't Work!
Help! Changing Springs, Air Compressor Method doesn't Work! I'm trying to change my valve springs so I hooked up the cylinder to the air compressor through the spark plaug hole and what not. Well, when its hooked up, I can hear this fairly loud and consistent hissing, like none of the air is staying in the cylinder. I have the timing cover off an the noise is the loudest coming from that area near the oil pump. I tried both cylinders 1 and 3 and both gave the same exact results. The air compressor was set at about 30-40psi. What's wrong?!?!
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It will hiss alittle bit past the rings.It will be real loud in the intake or exhaust if a valve is bent.I do them at 100 psi and check the tank pressure after each valve to make sure there is enough for the next.The valve will hold up there until 40psi,no problem.
TECH Junkie
Joined: Nov 2001
Posts: 3,604
Likes: 0
From: Los Angeles
If your front cover is off, this is a no brainer. Use the OTHER method listed on my site, and use the dot on the gear to tell you which pistons are up top. This method is about 10x easier than the air method anyway!
Its all detailed here
http://www.ls1howto.com/index.php?article=23
Its all detailed here
http://www.ls1howto.com/index.php?article=23
TECH Fanatic
Joined: Jun 2002
Posts: 1,227
Likes: 0
From: Indianapolis
Originally Posted by jmX
If your front cover is off, this is a no brainer. Use the OTHER method listed on my site, and use the dot on the gear to tell you which pistons are up top. This method is about 10x easier than the air method anyway!
Its all detailed here
http://www.ls1howto.com/index.php?article=23
Its all detailed here
http://www.ls1howto.com/index.php?article=23
I agree with Jmx. I switched from the air compressor method to the TDC method after changing two springs. It's faster and easier, make sure to take the plugs out before so you can spin the engine over easier.
I did mine with the air compressor and it was over 100 on all of them. It make the same hissing or leaking noise you described. Mine seemed loudest on the intake valves and the air would come out the TB. It worked and now it runs that is all we can hope for when working on one! 
Originally Posted by jmX
If your front cover is off, this is a no brainer. Use the OTHER method listed on my site, and use the dot on the gear to tell you which pistons are up top. This method is about 10x easier than the air method anyway!
Its all detailed here
http://www.ls1howto.com/index.php?article=23
Its all detailed here
http://www.ls1howto.com/index.php?article=23
Well, I upped the pressure to 95 psi and tried again and it worked! It is time consuming but what the hey... I got em all changed. Two or three were stuck really well and I had to gently tap the retainer to get the valve stem and locks off the retainer. The hissing on all the cylinders sounded the same so I guess nothing was wrong with the rings. Thanks a lot guys!