Here's the situation, my brother's 97 prelude base has a knocking sound that sounds like its coming from the head. At idle, its not a real fast knock like valve ticking, its more slow, like one of the LMA's is sticking.

Long story short, I have been researching alot before posting, and I found one thread where someone recommended testing them by holding the rpm at around 2k while supplying 12v power to the vtec solenoid, and if the ticking goes away then it is most likely the LMA's. This sounds like a good start to me, my only question is if its ok to engage vtec at that low of an rpm in regards to mechanical timing. I assume its ok, just wanted to make sure. Any other advice on testing is appreciated.

 

pull the valve cover, push down on the lma's and see if they're sticking.

 

Its that easy? I guess I didn't think that they would be very easy to compress, but if there is no oil pressure then I guess it would be fine. Has anyone ever solved it by putting some kind of oil additive? I'm not usually a fan of doing stuff like that, but maybe some sea foam in the oil would free it up? I have seen sea foam cure things like lifter knocking so its just a thought. I wouldn't have any problem doing the LMAs, its just that its a lot of time and money, and my brother needs the car.

 

UPDATE: I just now went out, took the valve cover off, and compressed all the LMAs by pushing down on the third rocker. All of them compressed, some compressed easily with basically no effort, some were pretty difficult to push down, but they all sprung up pretty readily. Is this normal? I'm not stuck on the idea of the problem being the LMAs, it was just the first logical place to start since its so common. Any other ideas are appreciated.

EDIT: Forgot to mention the car has about 116k miles.

 

they should be smooth and return with some resistance.

new h22 LMA are spring style and are under 9 bucks a piece. i would just order them. B series ones are like 28 so we (h22 owners) are lucky

 

So are you saying the LMAs are for sure the problem? I can only find them for like $23, where can you get them for $9? I still want to make sure thats the problem before I dig into the valvetrain. Here are a few pics of the exhaust cam, it looked a little worn to me so i took a few pictures.