Red Leader

So, I think I'm hearing a very slight knock in my 4runner. It is '97, 5 speed, 4x4 with the 5VZ and 185k. I bought it in VA and drove it out to CO and didn't notice anything then. Recently, oil was changed (10w30...had no 5w30 on hand) and a PureONE filter. Oil before the change was at normal level.

I'm trying to find out if it is the beginning of rod knock or something else.

So I start it up and the sound is only noticed after about a minute and a half. it is very faint. It does change based on RPM, from what I can tell. It does sound more like a knock than a tick.

I'm trying to track it down but so far its been hard because it is faint. You can hear it in the engine bay, underneath the vehicle, and also inside, but again it is very faint. It has a very, very consistent pattern - a lot of the rod knock youtube videos I watched had erratic knocking when blipping the throttle.

I might go get a car stethoscope and see if I can isolate it. Any thoughts? Anything I should be checking? I have heard that belts with too much tension can also cause a knocking. I'm hoping it is not the worst case scenario, but right now just trying to rule things out. Is there an easy way to test w/out dropping the pan? Access to the spark plugs is worse than other vehicles, but I will pull the plugs if there is a good way to test for movement there.

Thanks all.

HighLux

how bout a video of the noise?

Jomoka

Real rod knocks will vary considerably with changes to engine speed and load.

It could be a loose valve - they're adjustable via shims. But a light tap from there isn't really a particularly urgent issue.

Keith122

Valves most likely, sometimes the injectors make noise as well.

JasonYota

iTrader: (1)

Mine does it as well. I figured its a toyota thing.

YotaWoRx

google toyota 3.4 scissor gear knock

Red Leader

The video is a great idea. I appreciate all the ideas guys. I'll try the video, although it is subtle so I'm not sure how much it will get picked up on the audio - which is a good thing I suppose.

Heard it on the way to/from work today. Pretty much a constant thing. You do have to really pay attention to hear it. I don't want to say it is the loudest at the oil pan, but you can hear it clearly at the oil pan, though you can hear it in other places in the engine but some of that is drowned out by the fan/belts.

I'll try to get a couple of short videos up. You can hear it most when you rev up the engine between 800-2000rpm. At speed, you cannot really hear it. At idle, it is there, but more quiet. I've heard valve tick before - my old stanza used to do that when the oil would get low. This is definitely a lower knocking sound, but not quite as clangy metallic as most of the youtube videos.

I'm not sure if it is comforting or not to have other people say they have it too? I'd hate to say your vehicle issues make me happier But I'm glad I may not be alone. Thing is, we own a '98 also, and it has never made a sound like this. The '98 has 269k on it.

vasinvictor

iTrader: (3)

If it has 269k on it and it runs good otherwise I don't think I'd go searching for problems, especially for something as faint a sound as you're describing. Turn up the radio and enjoy the drive

Red Leader

Haha well it is the non-noisy 4runner that has the 269k on it but I hear ya man Stuff like this just makes me nervous I suppose.