Thread: Valve Spring Replacement without injectors

I pulled apart my motor to replace the crank and cam sensor; while I tear it down I'm doing rockers but I don't have the top end on there except for the heads so when I hook up my compression tester tool the air just releases right out the injector hole as I try to pressurize the cylinder. Whats the trick to stopping this? I'd rather do these while I have nothing in the way of the rear. Thanks!

put the injectors back in the head, and hit the valve springs with a mallet to help seal the valves in the head so they dont leak. and you leave the air in and on, dont un hook it or turn off the compressor.

Won't putting the injectors back in but not securing them down just cause them to blow out? I didn't hear any air leaking from the valves but I'll double check it and hit the spring with a mallet. Thanks for the tip.

Mike...Unbolt the rockers. That's what is holding the valves open. Once you do that..you are golden. You simply put air to the cylinders too early.

I did unbolt the rockers, took the pedestal off too. At that point all I have left are push rods and valve springs to take apart. I took the valve out of the compression tester tool, screwed it into the spark plug socket and then attached my compressor and I get a huge amount of air out of the injector hole. Like scottydoggs was saying could it be that after taking the rockers off as you said I need to "nudge" the springs a bit it should seal completely and allow me to compress the spring?

Ok..easy enough.. often our valves leak. Using a rubber mallet..I tap the valves to open them. The quick shutting usually seals them up.

Ah perfect, thanks Bill! I'll give this a try and see what happens.

There's a certain amount of leakage that you might get. But it'll be reasonable. And when you put the new spring on..give it another whack... usually the stronger spring stops the leak.

Ok, I just tried the mallet and was going to come back on to ask about a slight leakage. I mean it holds air but there was a tiny amount I could barely hear. I'm glad to know its an acceptable amount. Now if its any more than that then this would be the time to pull the heads an inspect I suppose. Thanks again everyone. Hopefully the LS6 springs will seal it a bit more, I'm glad I changed the timing chain because the tensioner had a huge piece at the bottom broken off and was worn pretty good.

Or have a valve job done. Most of our cars should get a valve job automatically. But..look at the work and cost vs dealing with a little leakage.