Valve adjustment question

[FoxholeAtheist]

I'll preface this by saying that I have very little tinkering experience, but I can follow instructions and know which way to turn a wrench.

I've got a 1990 Nissan Pickup with the 2.4l inline-four. I'm looking through the Chilton manual for it concerning valve adjustment, because there's a high pitch "clicking" or "ticking" noise that just developed. This noise does track with engine rpm, and I'm thinking that maybe I need to adjust the valves. So anywho, under the tune-up info, it says that all vehicles 1990-on have hydraulic valve adjustment. From my motorcycle days, I seem to think that this means that manual adjustment is unnecessary, and that I might have a non-valve issue. If any of you folks know enough about this to confirm my suspicions, I would appreciate the help!

Thanks!

 

[RARanney]

You'll have to search in an automotive site a little, but I believe even hydraulic lifters need adjustment on rare occassion. I've never done it, so search your model, perhaps.

 

[Cougar Allen]

When you hear valve lash in an engine with hydraulic tappets that usually means the oil is either low or dirty. Check the oil level, change the oil and filter. That doesn't always fix it -- sometimes a tappet is thoroughly gummed up. The next step, believe it or not, is to try some Marvel Mystery Oil on it -- you know that stuff with the unbelievable claims on the label? You can get hours of laughs out of that label ... really it's just a mixture of solvents and it can't really cure cancer or raise the dead or any of that stuff, but it can sometimes dissolve the gum that's clogging up a tappet.

If that doesn't work, just ignore it. You'll lose a little bit of horsepower at maximum rpm and full throttle, but other than that the engine will still run fine. You can get used to the valve train noise.

You don't have to ignore it; you could pull the tappets and either disassemble for a thorough cleaning or replace them, but IMHO it's not worth the trouble just to make an old truck run a little quieter and get a little bit more horsepower out of it.

One more thought -- there are a few engines that have hydraulic tappets and yet are supposed to have the valve train adjusted once in a great while. Check the manual to see if yours is one of those.

 

[FoxholeAtheist]

Okay, I had already added more oil. (It still burns more oil than gasoline, but I think the gap might be narrowing.) This is actually my fiancee's truck, though it will be half mine in two weeks. She told me that "It needs oil when I hear that funny clickly sound start up," but I was thinking it might be more than just needing oil. I'll keep the oil closer to the manufacturer's intended level and see if it goes away.