Question : Stupid 3.4L valve adjustment

[curtis73]

I have alldata and the tutorial on this site to help, but I'm still having issues setting valve lash on a 94 camaro 3.4L

First of all, I can't find a timing mark to line up with the balancer, (is there one?) so I used a welding rod in the #1 plug hole to find TDC. I went over several times and verified valve movement on #1 and #4 so I was positive I had the right stroke. At TDC #1 I set I-1,5,6 and E-1,2,3. Spun it over once and did E-4,5,6 and I-2,3,4.

Two problems;
1- After zero lash I'm doing one turn and instead of depressing the plunger, its opening the valve. I thought maybe they would bleed down so I left them alone for an hour and they're still open. And, yes, I properly set zero lash. I use the up-down pushrod method instead of the unreliable spin method.

2- I got done with the first round, then went to the second round and found that #6E was at full lift judging by the wear pattern on the pushrod from the guideplate. I spun the engine around twice with the welding rod in #4 and verified that it was TDC on compression. Verified that its the exhaust valve and not the intake.

All I did was an intake manifold gasket. Any help?

[60dgrzbelow0]

Hello Curtis...

These images are of the Valve Lash Instructions from the 1994 F-Body Carline Series GM Shop Manuals. Everything that happens properly in doing the Valve Lash in two shorts rotations comes off of the need for the #1 Cylinder to be at TDC on the Compression Stroke. If you are uncertain about ANY of the adjustments you have made so far...just take a very deep breath and relax...and then back off all of the nuts until all of the rocker arms are quite loose...and then with these images printed out as a reference (along with a simple Firing Order Diagram on hand as well) ...Just go through the engine rotation cycle again very slowly (with all the spark plugs removed).

It really helps to have someone on hand to press a sealing finger over the spark plug hole of the #1 Cylinder and they will be able to confirm from the hiss of compressing air that you are indeed on the final compression stroke when both valves will be closed. Then just make the necessary adjustments to the Intake and Exhaust Valves on the #1 Cylinder and follow along with doing other valves listed on the instructions. To complete the Valve Lash process...just rotate the engine one full turn and follow the list of the ones that remain to be done.

Once completed...rotate the engine VERY slowly and confirm that you don't feel anything hitting or resisting your efforts to turn the crank...if you feel ANYTHING...stop and re-group. Better to be safe than sorry about bending valves and lunching all your good efforts!

Good Luck!

--==Bob==--

[curtis73]

Ok, thanks. That is verbatim what Alldata has as well. I've done it a few times since I posted and I'm confident that its done right, maybe these lifters just take a long time to bleed down. I'm going to go have dinner and then do a quick compression test before I seal up the upper manifold. Thanks.

[60dgrzbelow0]

Just curious ...but what build - re-build are you working on and what components have you put in? Is the engine in the car...or on an engine stand while you are doing all of this?

[curtis73]

Its a stock engine in a 94 camaro that started leaking (no, hemorrhaging) oil from the back of the intake. I just did an intake manifold gasket set. Stock engine, no mods, in the camaro.

But... crisis averted. I felt confident enough to reassemble it all and it runs fine. Just took almost two hours for those lifters to bleed down. I can't explain the #6 pushrod being so high, but who knows what had been done in there before the customer brought it to me.

That's the embarrasing part... I run two repair shops and I had to ask for help on a GM V6

[geoffinbc]

I never adjust them like that. I always do them one cylinder at a time. When the exhaust valve begins to open you set the intake. When the intake begins to close you set the exhaust. It takes longer but it much easier to follow. Plus you don't have to worry about the cylinder position.

[60dgrzbelow0]

I forgot to ask...but when you had the Oil Pump Drive in your sights with the IM undone...did you replace the PTFE "O" Ring, too? It's uncommon for them to leak like sieve like the old Black "O"Rings in the early versions of the 60* engines...but more and more...those older black o-rings are showing up for cheap all over the place that were made for the 2.8L engines. I only ask because it is also a source of oil leaks at the back of the manifold that might masquerade as a leaking IM seal.

[gunther]

This is good information but because I'm doing the same job (intake gasket-thanks for the tip on the oilpump gasket) However...........how do I know which is the exaust valve and which is the intake?
Thanks!
-gv

[pocket-rocket]

You can look at the intake runners and follow which way they curve. They always point towards the intake valve. At least, that's how I do it since I haven't gotten the order of the valves memorized, being a DOHC guy and all.