Ok, so I ripped my valve cover off to adjust my valves finally because it's been tapping like crazy since I bought it. I go to check the clearance on one of the #1 intake valves and I see the rocker (I think? Whatever it is that the cam rolls over to push the valves) move back and forth when I was moving the feeler gauge around. Not good. So I thought maybe the adjustment nut was really loose. If it were only that easy.. Seems to me like the stud is broken. I checked the rest of them and 8 out 16 of them did this.. Not good at all.

The ones circled all wiggle back and forth and I can pull out about 1/8"



Edited pic for iServe hosting now

Does anybody know what the problem is? How hard is it to fix, because it can't be good. It looks like I might need to rebuild the entire head because I looked at the cams and they're bare metal on the problem cylinders but have a tan-brown coating on the normal ones.


Modified by 91TegLS at 2:58 PM 2/10/2005

 

Well from that pic I can tell you have #1 set at TDC. All the ones you circled that are moving, all of those have the valves closed, and the cam lobes are pointing up and away from the rocker arms. The other ones have the cam lobes pushing down on the rocker arms, so of course they aren't going to move.

Did you loosen the lock nuts? You can't just reach in there and turn the adjusting screws, you have to loosen the locknut first and then adjust the clearance by turning the screw. Then you hold the screw in place w/ a screwdriver while you tighten the lock nut. The rocker arm is going to move some when the valves are closed, because there is supposed to be clearance when the engine is cold.

Also you do know that you're supposed to turn the crank 180 degrees after adjusting each cylinder's valve lash, before moving to the next cylinder, right? In the firing order 1-3-4-2....

 

So what you're saying is that this is normal? I haven't touched anything at all, just set #1 to TDC and noticed they were moving and didn't think it was normal. Now here I am.

 

If it is normal, the valves are way out of spec anyway.

One of the #1 intake valves was 0.008!

Helms says
Intake: 0.003-0.005
Exhaust: 0.006-0.008

 

I agree with Pat, there should be a little movement on each rocker (it should be able to jiggle back and forth). Go through the process of the valve lash adjustment, and you should notice that whenever a cylinder is at TDC it should be 'tighter' than the rest.

It's fine if the valves are out of adjustment right now, at least you know why they were ticking. If you went through the whole thing and every single valve was already within spec, wouldn't you be concerned that there is another reason for the ticking noise?

 

Well of course there could be too much clearance, but the rocker arm will always have a little bit of freeplay when the engine is cold and the cam lobe is not pushing against it, because of the clearance that you set w/ the feeler guage.

In your pic, all the valves you circled are closed. The valves you did not circle are being pushed open by the cam lobes. So on the #1 cylinder, check the clearance first, and if it's too much, loosen the lock nut, and turn the adjusting screw tighter until there is a slight drag on the feeler guage. I like to use the next thicker feeler guage to make sure it will not go in. Then hold the screw where you set it w/ the screwdriver so it doesn't go any tighter, and tighten the nut.

Don't set the clearance too small, as you run the risk of either burned valves, or possibly the valves not seating all the way when the engine gets up to operating temperature.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91TegLS &raquo;</TD></TR><TR><TD CLASS="quote">If it is normal, the valves are way out of spec anyway.

One of the #1 intake valves was 0.008!

Helms says
Intake: 0.003-0.005
Exhaust: 0.006-0.008</TD></TR></TABLE>

haha that's not way out of spec. Way out of spec is like the time I attempted my first valve adjustment. I made the mistake of just loosening all the nuts first before checking any of them, and I guess I missed one of the exhaust valves. I ended up driving 200 miles from my parents' house back to my apartment with one exhaust valve's lash at probably .030" or more, damn engine sounded like a deisel.

 

.030 wow.. that can't be too healthy. Good thing you got that fixed.

 

Yeah I was about ready to take it to the shop because me and a friend thought we checked all of them and couldn't find the problem. Then I decided to check it over one more time, and finally found that one.

I don't think it would really cause much of a problem, it just makes for a noise valvetrain. Over a long period of time it could probably cause more wear on the cam lobes and rocker arm pads. The valve might not open quite as far as it should, but it wasn't that big of a deal for just that couple hundred miles. It just sounded really, really crappy.

 

Just a little update. The valve adjustment is done. The car runs beautifully now, and it's great not hearing the valves tapping away constantly. I think I might have actually regained some lost power from this too.

All I can say is that experience is definitely the best learning tool. I've read up on how to do the adjustment so many times I thought I knew everything possible without actually doing it. It never even occurred to me that the clearance would cause the rocker arms to wiggle around like that. All of the how-to's I've read never mentioned it, or I overlooked it. But now that I'm aware of it, it's so obvious I feel like a moron. Oh well, gotta learn sometime.

Thanks for the help Patrick. Maybe this thread can help someone else like me out in the future.

-Dave

 

You probably did gain a couple hp, because your valves may not have been opening all the way if the clearance was too loose.