Andross

My '85 300zx has been doing this for a while and I dont know what it could be. when it has been driven for a little while it makes this ticking noise. That harder I drive the louder the sound. When I change or add oil the sound stops for a little while. First it was months before it would return, now it's weeks... anyone know what it might be?

NismoPick

Could be tons of things.... could ya be more specific? Like.... what area the tick is coming from.... is it loud.... quiet.... metal scraping sound?

Andross

No, not metal scraping and the faster I drive the louder it gets during idle. the speed of the tick also increases at higher RPMs. I'm not sure where it's coming from other than under the hood.

FreeLanceBum

Sounds like your valve lifters.

duowing

I've also heard that the fuel injectors will tick. As they get older they aren't as quiet and I guess as it sprays fuel, you'll be hearing that, although I could be completely wrong.

jfairladyz

Yeah the injector click as well. But if you listen carefully you can usually tell if it's the injectors or not.

91Zman

sounds like it might be lifters

NismoPick

Since it's an overhead cam, I'm gunna say it's not the lifters

Could be the ROCKERS... they do make a clacking sound (when not adjusted correctly) that increases w/ rpms.... but there are no LIFTERS in the VG30.

jfairladyz

Actually the VG30 DOES have lifters

NismoPick

oh yes yes... thas what I meant to say.

FreeLanceBum

The VG30 has hydraulic lifters(they automaticly adjust themselves), these can get pretty dirty and glogged up with age and lots of miles. When they do get blocked up, oil will not pass through then as it should, and wont allow for the adjustment, thus the clicking from a lack of a cushion of oil.
If it is the lifters and not the injectors that is.

jfairladyz

Here's a link to cleaning hydraulic lifters. It's not specific to our cars but the practice is the same.

http://www.atlanticz.ca/zclub/techti...r+cleaning.pdf

WolfMan

link does not work......

NismoPick

Worked for me.

jfairladyz

You have to have Adobe. It's a PDF page. If you're running an older version it may just be slow or you may need to update Other than that it should work.

NismoPick

Andross... any way that you can record the sound & put it on ya comp? Maybe w/ a camcorder or digi-cam? I think if we heard the sound, it would be easier to tell what ya mean.

jfairladyz

A piece of vacuum hose will tell you where the sound is coming from