wdtony

Quick update:

I have spent a lot of time today with the cheap stethoscope I have, listening all around this engine.

I noticed one distinct difference between the front valve cover and the rear valve cover. The more pronounced TAP that I am aggravated with seems much louder on the rear valve cover.

The front cover seems to be the normal valve-train sounds.

robbyk

Is the noise more pronounced in the car in the passenger side than standing outside next to the engine with the hood open when the engine is running?.

What I am getting at, is that the suspicious cam (3 cylinders) that produces the noise is very close
To the passenger side of the vehicle.

OceanView

You might need a valve adjustment. I am leaning toward this on my car at the moment.
Here is a Valve Adjustment DIY on a 1MZ-FE engine which is similar to the 3MZ-FE engine you have on your car.

http://www.toyotanation.com/forum/10...mz-w-pics.html

This is probably too involved for me to do on my own but if you have the patience, time and experience you could attempt it if your engine needs adjustment.

wdtony

@Robbyk:

I will try to answer as best I can.

The noise seems to be loudest when I place my ear in the driver's side wheel-well.

The noise is less loud at the passenger side wheel-well.

Inside the car I can also hear the noise but all of the other engine noise is quieted by insulation and the tap is more distinct.

The engine is mounted transverse and the sound on the valve cover is loudest on the rear valve cover. When listening above the engine, the sound seems loudest nearest the timing belt and pulleys side of the engine.

The engine has a DOHC so there are 2 cams per head. And there are 2 heads for those reading not familiar with this engine's type/position etc.


@Oceanview:

Really thanks for the link! \ I really need info like this, it was a well done compilation of info. I am hoping the lifters on the 1mz-fe are the same as the 3mz-fe engine. I have read there are differences like no VVTI on the 1mze but it's very possible the basic valvetrain mechanics are the same or almost the same.

If I do a tear down I will post pics and videos here, but it might be a long time before I can do that. And I am not entirely sure if that's my issue yet. But plugs need changed anyway and valve covers are just starting to leak, so probably will be doing this job eventually.

wdtony

I understand what you mean, yes I believe the "cam in suspect" is closest to the firewall and to the inside of the vehicle.
I still plan to do more observations tomorrow because it was raining the last 2 days and I don't have a garage. I want to more accurately pinpoint the sound if I can and establish top end or bottom end. I am feeling about 75% it is top end rear head.

wdtony

Spent more time listening all around everything today. I am no more closer to figuring this out. Using the stethoscope I listened to all 3 cat converters and exhaust. Nothing worth reporting.
I listened to the bottom of the engine and the oil pan area etc. No real sounds coming from there. Sound is not from any pulleys or power steering pump. Timing belt circuit is not it either. Nothing from the transmission area/torque converter/flywheel.

And l listened all over the top end again with the same results as before. It's such a difficult sound to pinpoint using the steth..... which is weird because it is easily heard by just listening with my ears. I may check a few more times when the sound is loudest but I think I may be at the end of what I am capable of doing at this time.

I'll probably take off the front valve cover and check shim/lifter tolerances and put on a new gasket. And just check around to see if I can learn anything before tearing into the back. Plugs need replaced anyway.

LazarusLng

If it is just an annoying noise that you are trying to fix, and not something that is effecting performance, I wouldn't go any further than replacing the spark plugs. Maybe you enjoy tearing into your engine? Every vehicle I have ever owned has had some strange noises at on time or another, and none of those motors ever had a real problem. Nissan, Jeep, Chevy, and Toyotas. They all had some sort of noise, or vibration that could drive you nuts.

JProdun

Not that it helps in any way, but I remember someone on the forum saying that it's the lack of noise that one should be worried about.

wdtony

I hear ya. Every time I think I can live with it, it starts rapping and it sounds bad, bad enough to pay attention to. I've owned about 25 cars in my life, never had a sound like this one. I feel like that cap'n Ahab goin' after the whale.

To change the plugs on this vehicle all the breather assembly, throttle body, plenum, et cetera has to be removed anyway. I would hate to spend all that time and not look inside the valve cover... which has started to leak anyway.

I believe I can check shim to cam lobe tolerances without tearing down much more. I do enjoy tearing into something if I can put it back together. I used to repair industrial machinery so I am eager for some practice.

LazarusLng

Thats cool. I know it would be very satisfying if you can track down and eliminate the noise.

thomas1

Just another thought maybe the variable valve timing gear assembly is failing causing the off timing situation. But I would think it would throw a code....

wdtony

yeah, no codes, no performance issues at all. No misses or rattles, etc. Still, I appreciate outside of the box thinking. Many fixes are found this way.

If I didn't pay so much for this vehicle I probably wouldn't want it to prrr like a kitten. but everything else on it is so solid, it's a shame to have this little annoyance. If i have to live with it I will, but not until I know I have to

wdtony

It is definitely a metal on metal knock or loud tap when it happens. But it is quieted at startup and quiet after driving about 5-10 miles. Then, let it sit for about 45-60 mins and then at startup again, the sound is quite loud.

OceanView

Have you taken your car to a mechanic?
I have a similar metal on metal taping noise on my engine and after taking the car in to an Indy, they are saying that it's the metal shims used to adjust the valves. I think you may have the same design on your engine as on my 1MZ-FE and may have the same issue.
He said this issue will not damage the engine but it will not go away.

I'll get mine fixed after I get my tax return back but until then, I'll have to deal with the sound.

wdtony

Yes, I believe both engines have DOHC and the shims. I really hope that's what it is. If you do have success please post an update here. I will do the same but am waiting on money like you. I need to change plugs and valve cover gaskets anyway so it will probably be one big job.

I haven't had a mechanic tear into it, no. He only listened and couldn't pinpoint it from listening.

I found a way to measure the shims online: http://highlanderclub.ru/files/manua...1p/a040001.pdf

But after reading, it seems that the lifters are more likely to wear underneath than the shims due to hardness of the metal.