Is this sound Tapping? How many days to live, Doc?

[jbtvt]

Never owned a 3.4 but my first thought was that sounds like injector noise. Was some of that audio through the stethoscope? Scrolling down it looks like what you have your stethoscope on might be the fuel pressure regulator. Before you open up the valve covers check the fuel pressure. Keep an eye out for spikes which might signify a damper issue.

 

[4Runnermex]

Looks like that may be in order, Thanks.


ouch, that's not what you want to find, hope you didn't pay too much. Mine was $4500 with 130k but needed lights/bumper/grille/hood, about $500 at Certifit assuming the rad support will bang out. If not i'll attempt a cut/weld. I'm gonna have a closer look, then, before moving too much forward with this one. Don't have the work space here for an engine swap. HGS > Head gasket?, why was the oil pan brand new?

Thanks bugman for going to the trouble to post that pic. I'll let you know if mine makes any noise for reference.

I bought it for 1500 considering it was ticking. I gambled it was the lifter issue. I convinced the previous owner it had big issues and he dropped it to 1500

Redo Headgaskets for about 400 total. Still not bad

 

[yotatech29]

my 4 runner had this same sound and found that one of my spark plugs backed it self out causing this tap sound but i was lucky enough to not kill my heads because i drove it for some time so replaced the plugs and wires
311,500 mines still running strong and smooth

 

[mtncrzr]

I have an obnoxious tap/click also - but its from the vacuum switching valve assembly.

It's great when you're "sure" of something, and just travel down that road, blind on a one way track. I thought this switching valve thing was highly unlikely and almost as an afterthought checked it out today when moving the 4runner after the 30" or so of the snow we got this week, having spent much of the week looking into ordering valve shims, gaskets, etc. and prepping to dive deep into this. But a quick check and there it was, the noisy vacuum switching valve, clacking away like a little freakin' locamotive.

I about flipped, so happy I was to find it's a small thing; that's how much I dislike getting burned on a used vehicle, especially when you look back and say "that's why he said this and that...". But sometimes it works to your advantage, last year I bought a Blazer, yes I said it, from a college girl 'cause it was "running rough". Drove it away and at the first stop gas station, snapped the #5 spark plug boot back on and the 4.3l was screamin right along. Nice strong engines, and 20mpg. But after spending 3 months on the forum discovering there's about a million things that go wrong with those vehicles, and no diff lock, I let it go and made my way to the 4runner world.

Huge Thanks to you for identifying the simplicity of the issue on this 4runner! Did you just leave it as is? or maybe it's time for inspection/replacement?

One guy was having a code (no codes here) for it being stuck open and had success spraying with carb cleaner and then lubing with WD40, but obviously that's a separate issue, though maybe it just needs a bit of lube to quiet down. I see them listed around $60+, $78 for OEM (no yards around here).

 

[gmv4k]

Anybody know the part number?

 

[gamefreakgc]

I narrowed it down to the driver rear cylinder, most likely.

For adjusting valve lash, is it general consensus that removing camshaft is usually necessary and measuring with feeler gauge before will be accurate for calculating new shims needed? I'm an hour from parts.

I'm not seeing a Sticky on procedure.
I'm still looking for the best thread on steps, tools, shim dia.> order Toyo Shims by number 1 to 17 as necessary and thats all that's needed for correct shim size/dia? As on pg.819 of FSM no dia. listed. Spec is Intake set to 0.18 mm / Exhaust: 0.32 mm

So far I know to use magnet and maybe the special plier & or pry tool and that I'll probably have to remove camshaft.
Will visual inspection for damage to cam/bucket be obvious? I guess I'll try to mic the cam maybe but that will be hard to have a reference point, and I will take any sign of wear to mean replace part. Is it safe to say that if tapping persists after engine flush, that there is excessive wear somewhere and something will need replace? (hopefully camshaft or bucket, not valve or valve seat)
Can I start with just driver side and if they are all out, proceed to passenger side, otherwise just fix bad one? I guess with all the intake stuff removed, it's worth it to just have a look at passenger too? I'd rather not mess with a good gasket if unnecessary.

It sounds like driving on this may eventually result in burned valves and damaged heads, but it also sounds like that's pretty rare. How long have people driven their 3.4l with the valves a bit out & tapping?

30 degrees out this morning idling, it took 10 minutes Before any noise was audible. With stethoscope it was slightly more noticeable than other cylinders before that. The tapping came after a bit and then it also got quieter, barely noticeable to naked ear, at idle I guess it comes and goes, so maybe a simple flush will help. Sound was much more pronounced yesterday after driving a few miles (original soundclip), but was definitely steady at that time, not going away. Vehicle is new to me.

It may be a sign that the noise was most prominent when I placed 'scope on the little vacuum thing coming off the intake by firewall >plse. see photo. Placed there, it sounds almost like a knock, but I'm 98% sure that's the acoustics of that particular element but thought it interesting that it was so pronounced right there. The lower end sounds fine. And by ear, the sound is definitely an upper end tick which sounds quite close, not muffled, and not any lower octave knocking.

I do my best to keep these short, taking an hour or more (or several) to write and whittle down. Thanks for reading.



Thanks Singtoe, gamefreakgc, alanflies, I'll try the seafoam and oil change first. Sounds like it should purr along with valves properly adjusted.


Thx! plse see above.


Thanks, will do filters.

Thank you much for taking the time to post your engine sounding good!


Thanks, will have a look.

WAIT!

Is that photo and comments yours at the bottom of the above post and your comments? If yes that's your fuel pressure regulator you have pointed at in the photo. They will tick as they age. Completely harmless, just noisy. The reason why you said it sounds like top end is because it's the FPR which is on the top of the engine.

Don't worry about your valves then. If you want you can take off the covers and measure the clearances but it's a bit of work to get that far so not necessary.

Drive on and be at peace fellow 4Runner owner.

 

[mtncrzr]

Yeah, ok that's the FPR, good to know they can be noisy too, thanks. It sounded like a knocking inside there, and there's something called injector knock I haven't looked into. The main ticking noise it turns out was coming from the vacuum switching assembly in bugman-74's pic above. I've not been familiar with noises coming from other than engine, and did not suspect it, so valuable lesson learned.

 

[gamefreakgc]

Sounds good. I just didn't want you tearing up your engine and putting it all back together only to find the noise is still there.

On the 2nd Gen 4Runners they would tick so loud it drove people NUTS. My injectors and FPR ticked pretty loud on that engine but they worked fine so just learned to live with it.

 

[tarsotenorio]

Need Help From Brasil

Guys, firs time posting here! My name is Tarso, I'm from Brasil and just came back from San Diego - CA. While in SD I had a 2000 4runnner with more than 300.000 miles and I used to love the car. Actually I still love it, but I had to sell it to come back. Now that I'm back in Brasil, I'm trying to find "the one" that I will take with me forever, but it's hard to find the one here in Brasil.

Last week I thought I had found it, but unfortunately, It's in another state and I would have to travel to see it in person. So I asked the actual owner to send me a video of the car with the engine running, and that's what I got:

https://www.youtube.com/watch?v=tvnK98w7JT0

Whatching the video I realized that there is a strange tapping noise while the engine is on. Not sure what it is, but making a good research, I got to this thread. My question is: Do you guys think the car from the video has the same VSV (Vacuum Switching Valve) problem, or is it something more serious like a valve problem? Please help! To me it seens like the same tap noise.

I've been dreaming with a 3rd gen 4runner since I sold mine in SD, but not sure if I should give it a chance and travel to another state to check the one from the video out.

PS: sorry about my english!

Thanks