The following is the dialog that goes along with some pictures I took as I replaced a lash adjuster on my car. Reading this might be a little like listening to the TV playing in another room, so you might just want to visit the site (I hope it's not too sloooow). The ActiveX control is the windows media player so you can hear what the engine sounded like before I replaced the HLA.
This is the engine in a 1990 Mazda 626 GT (Turbo). I started getting valve noise a couple of weeks ago. My mechanic said to try some "Marvel Mystery Oil" for a week to see if that would allow the HLA (hydraulic lash adjuster) to pump back up again. It didn't. It kept making the noise, so I bought a new HLA ($28) and put it in. I decided to take a few pictures.
I'm not a professional car mechanic, so I might not have done all of this right, but it seems to have worked (the wav file that played when you loaded the page was before I replaced the HLA).
Here's the engine with the valve cover off. This engine has a rubber gasket, so it's not as critical to have a new gasket each time you open it, like with the old cardboard gaskets. The manual does suggest using a silicon based sealer in a couple of small spots on each end. Anyway, under each one of those shiney silver circles on the end of each of the rocker arms is an HLA.
You can't really see the HLA from here, but it resides inside of the rocker arm. On top of the spring is the end of the valve. That's where the HLA and valve come in contact with each other.
Here's a shot where you can see the HLA.
I was able to identify the problem lasher just by grabbing each arm and attempting to rock it. There was only one arm that moved at all. If I was more methodical, I might have tried a feeler gauge between each, but when I found this one, and I only bought one HLA, I just quit looking and got to work on getting the new HLA in there.
Here the shaft that holds the rockers has been removed (I just set it down on top of the cam shaft (I don't have a clean bench nearby). You can see the four HLA's. I was lucky that it was the forward shaft... the rear shaft had 8 things to worry about... the front one only had
Here's a closer shot of a few of the HLA's.
The HLA nearest you is the one that's flat. It's even obvious from this photo that it's bad.
The bad HLA slid right out with just my fingers.
At this point, I consulted the shop manual, because I understood these things needed to get pumped-up with oil. This of course is just saying you fill the reservior and it put it in.
The intent here was to record the torques required for reassebly. The shafts go in with 13-20 ft-lb and the valve cover is supposed to be
52-69 inch-pounds.I had to reorient the shaft so the reservoir would hold oil, then I put the new HLA in there.
There is is again, a little closer.
I don't know how a real mechanic would do it, but I found that I didn't have enough hands to compress the springs that keep the rocker arms in place. So I improvised. The springs are not hard to compress, it's just that unless you have them compressed, you won't be able to seat the shaft properly. I was able to jockey the shaft back into place after a few minutes of trial and error. And that's it. I put back the shaft bolts and valve cover bolts and was done. When I first fired-up the engine, it still had a slight tick, but the next time I started the engine, the tick was completely gone (I guess the HLA hadn't had a chance to fill with oil when I first started the engine).