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

[mtncrzr]

1998 LTD 6cyl 130k miles.

EDIT>>This has been identified as the Vacuum Switching Valve! Sounds like valve train noise until you know what you're looking for.

Please have a listen to my engine. All engines make noise, but the tapping this engine is making is quite dominant when you are a few feet from the engine or further. Up close, it's a bit tougher to pick out from other engine noises, but is noticeable. It sounds top end (of course), driver side, but I could not narrow it down more than that, even with stethoscope. The valve cover sounds about the same all along, and engine block is similar. Nothing super grindy with the stethoscope. The first soundbite is from a few feet away, and then closer. The sound is easier to pick out from a distance first.
I'm expecting to hear "that's just the toyota tap" or something, but it seems a bit more serious to me. I have listened to 10 or so other 4runners and there's always a bit of a tap, but this one is definitely pronounced and the worse of the one's I've heard. A bit of a rush purchase and noise wasn't evident at first.

https://www.youtube.com/watch?v=rY5mIDHetbM&feature=youtu.be

I bought it for $4,500 with 130k miles (front bumper collision), and also a '96 LTD with 230k miles for less, deciding which one to keep. The '98 is much more plush and nicer vehicle by far but I'd like to know what I can expect, worst case or most plausible scenario with this noise. Timing belt has been changed. Please let me know if there is further investigating I can do, but it's 20 degrees outside and no driveway or garage, public street only at my current town location, so please go easy. :typing:

I had a quick look at the dipstick when buying it last week, but not hearing the sound right away, I didn't take note or inspect oil too closely. I'm sure a change would help a bit, but it's in otherwise excellent shape and I believe it's been well maintained, actually owned by a Toyo Service Manager 5k miles ago who was a friend of the current PO, so is SHOULD have been passed along as a good vehicle.

Thanks for listening, and plse let me know what you think!

 

[Singtoe]

Sounds like a valve lifter. You might need to flush the motor with sea foam and put new oil in it.

If that doesn't fix it, you will need to check the valve adjustment, replace the worn out bucket or camshaft.

 

[jgue467]

Not too shabby...

yeah valve lifter related. I don't think that sound is Too far from normal - PLUS you are at 9200 feet!
That alone does a number on the engine, like a 27% drop in amount of air to breathe so go EZ on her!

Mine is just a bit quieter on the top end. I'd run seafoam (ounce per quart) for 300 miles then change oil/filter using a full synthetic like Shell's rotella t6 (5-40) with a purolator PL 20195 (larger than OEM) filter making sure the oil level is full. Don't forget a new air filter. Now listen to it. Then guage efficiency (fuel mileage) to determine overall operations and go from there. Luck and Enjoy! :cowboy:

 

[99Runnr]

Definitely not the Toyota tap, that is not normal for a Toyota. Don't let anyone tell you these engine's sound like an inline 4.0 Jeep engine. I got rid of 3 of those piles of shit cause they make so much noise "naturally" you can pass off blown engines and rod knock for normal.

Marvel mystery oil is like $3 at Walmart and works great for cleaning out internals.

Have you noticed any sound variance from colt to hot operating temp?

 

[gamefreakgc]

Sounds like a valve lifter. You might need to flush the motor with sea foam and put new oil in it.

If that doesn't fix it, you will need to check the valve adjustment, replace the worn out bucket or camshaft.

My guess is that it's in need of a valve adjustment. Sometimes changing oil can fix it though.

When I got my 4Runner the oil was as black as night. I had the shop use two "engine flush" chemicals to get the slop out of the engine. Works great now. It's a lot more potent than seafoam or MMO so if you do use, please be careful and follow the directions exactly.

 

[99Runnr]

Might not make any difference, but this is how it should sound. Loudest thing (outside my intake) is the injector pulse. There is no ticking whatsoever.

https://www.youtube.com/watch?v=tVSF6eJ_ers

 

[alanflies]

Sounds like a valve lifter. You might need to flush the motor with sea foam and put new oil in it.

If that doesn't fix it, you will need to check the valve adjustment, replace the worn out bucket or camshaft.

I agree... sounds typical of this...

 

[Brentif]

Have you checked the spark plug closest to the firewall on the driver side? I had one that was not all the way tight, and it was bouncing around in between the plug wire, and the hole it fits in. Easy to check, with the motor running, put a finger on the wire close to the plug, and see if it is tapping against it.

 

[mtncrzr]

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.

Sounds like a valve lifter... flush..with sea foam and..new oil. .. check the valve adjustment, replace the worn out bucket or camshaft.

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

Have you noticed any sound variance from colt to hot operating temp?

Thx! plse see above.

I'd run seafoam .. oil...air filter.

Thanks, will do filters.

Might not make any difference, but this is how it should sound.

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

Have you checked the spark plug closest to the firewall on the driver side?

Thanks, will have a look.

 

[kolelt]

Adjusting valves on these I heard is pain in the a** . mine also taps,but sometimes it doesn't tap. It's weird. And you only for 130k. I would think the valve shim would go bad at way higher milage. When mine taps I can hear it inside my car when idling at a red light. Then goes away at higher rpms. Then there would be days where it doesn't tap. Idk, these motors are known for Toyota tap noise.

 

[fenrisx]

Mine makes a similar noise, but not quite as bad... haven't really paid much attention to it, but glad to know what it might be! I just came here because I haven't been on the forum in a while, and just happened to click your thread and learned something new.. Nice!

 

[St Runner]

Don't worry about changing the shims until you have checked all the clearances. Think of it as a three part process, one to check the gap, next to measure the shims and the third to replace. Steps two and three don't need to be done if it is in spec. The 3.4 is not known for losing adjustment like the 2.7. Pulling the valve cover off will also give you a good idea about the general condition of the engine, My guess is that it going to be pretty ugly as far as crud buildup.

 

[bugman-74]

The 3.4 is not known for losing adjustment...

Agreed - for what its worth, I checked clearances on my 3.4 at 140k miles. Everything was in spec except for 1 exhaust valve at .016" (spec is .011-.014"). It is the only one I swapped shims on.

Many of the shims can be done with the special hook/plier tool, if you have a lot of patience.

I have an obnoxious tap/click also - but its from the vacuum switching valve assembly. It seems to start making a racket after the engine is warmed up. You may try probing around the vapor/charcoal canister on the drivers side wheel-well with your stethoscope and see if anything there is contributing to your noise.

 

[99Runnr]

Well, foot in mouth if these engine's are known for ticks.

First I've ever heard of it having owned several/still own 2 with higher miles. I got offended cause it reminded me of the Jeep 4.0 hiatus ray:

 

[Singtoe]

Well, foot in mouth if these engine's are known for ticks.

First I've ever heard of it having owned several/still own 2 with higher miles. I got offended cause it reminded me of the Jeep 4.0 hiatus ray:

Is this southern talk for something cause I don't understand what you said.

 

[mtncrzr]

Thanks for all the replies, it sounds like a lot of people just drive on it with the tapping, and that I should definitely consider other possibilities, but from what I hear continued driving on it may possibly result in bigger problems (burnt valves, removing & rebuilding heads, etc.)

I have an obnoxious tap/click also - but its from the vacuum switching valve assembly. It seems to start making a racket after the engine is warmed up. You may try probing around the vapor/charcoal canister on the drivers side wheel-well with your stethoscope and see if anything there is contributing to your noise.

Thanks bugman, this sounds similar, mine makes the sound after warming up quite a bit also, and did you see the pic I posted above where it's the loudest (by using stethoscope) is the little vacuum thing coming right off the intake between the intake and fire wall, sounds like knocking in there. Can you elaborate on the vacuum switching assembly issue you had, what you tried/the possible fix, and was it similar to a valve tap in frequency,etc? I'm gonna look into it's location,etc. Thanks!

 

[rmlamp]

I'm at altitude too but my engine runs pretty quite, almost no ticking, even at 189,000mi. I would pull the valve cover off and see if you have any glaring problems. I know it's a lot of work but it might be right in front of your face. Running some seafoam wouldn't be a bad idea either and some synthetic, I run Valvoline Synpower with Maxlife. BG MOA is great stuff too.

 

[4Runnermex]

Just checked an 2002 I purchased with the same ticking noise.

Thought it was thin 5w-20 oil causing it. Drained it and added new, upon disposing of my old oil I found metal shavings at the bottom of the brand new oil pan. A lot!!!

So now I redoing HGS on a 2000 engine with 100k miles to drop in this one. Since it's pretty much on its last leg

 

[bugman-74]

Can you elaborate on the vacuum switching assembly

See pic below for vacuum switching valve. Not sure if this is a source of your noise, but its worth a check. (FYI the rubber isolator on mine was broken, which is why you will see a button head cap screw and a few rubber washers attaching it).

Mine is quite loud - I can hear it inside the cab. I have compared it to a friends 3.4, and his is significantly quieter. I can actually pinch the tubes with my fingers and "feel" the pulses. To the best of my knowledge these click audibly under normal operation. One of these days I will pull one from a junkyard and swap it to see if it makes a difference.

 

[mtncrzr]

I would pull the valve cover off... I run Valvoline Synpower with Maxlife. BG MOA is great stuff too.

Looks like that may be in order, Thanks.

I found metal shavings at the bottom of the brand new oil pan....So now I redoing HGS on a 2000 engine

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?

See pic below for vacuum switching valve.

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