Engine noise? 3RZ experts please help

[owyheerat]

Does this sound normal for a 3RZ? https://goo.gl/photos/E6m2Hisw9WeZwYqR7

Some info. I bought this 99 4Runner in Jan of 2014 with 197k, it was in good condition, but had a slightly rough idle (engine would 'wobble' side to side ever so slightly). It ran fine and got good MPG, no codes and it never stalled or hesitated. The idle annoyed me, and I didn't know if it was something that could cause premature engine wear. I went through and changed all fluids to Redline synthetic, replaced plugs and wires, PCV valve, cleaned throttle body, IAC, MAF, etc. This did not fix rough idle. I drove it like this for 18 months and 12k. It seemed to be getting a little worse, so I took it to a local shop, and they said the valves needed to be adjusted. The valve adjustment fixed the wobble, but now it is louder than it used to be, and I'm not sure if this is normal for the little 4 cylinder?

Any info appreciated.

Thanks

Durwin

 

[UnderFire]

I'm gonna go out on a limb and say it's probably fine, my 3RZ and the 2 others I've been around have all made that same noise.

 

[Kanoe]

I'm no expert on anything, I'll start with that. Nice clean engine by the way.

I find it hard to tell from a video clip but it does sound rappy to me. Mine runs pretty smooth and quiet. Not sure how mine would sound on a video though... It got worse after a valve adjustment? That sounds odd. Did they give you a print out of before and after valve clearances?

To speak to the idle issue, removing and cleaning both the throttle body and IAC valve made quite a difference in smoothing out my idle and raised my idle speed from 650ish RPM to 700ish RPM. Right where it should be.

 

[owyheerat]

I'm gonna go out on a limb and say it's probably fine, my 3RZ and the 2 others I've been around have all made that same noise.

[MENTION=90352]UnderFire[/MENTION], thanks for response. I don't have any prior experience with this engine, nor do I have any friends with it. So I have no point of reference.

I'm no expert on anything, I'll start with that. Nice clean engine by the way.

I find it hard to tell from a video clip but it does sound rappy to me. Mine runs pretty smooth and quiet. Not sure how mine would sound on a video though... It got worse after a valve adjustment? That sounds odd. Did they give you a print out of before and after valve clearances?

To speak to the idle issue, removing and cleaning both the throttle body and IAC valve made quite a difference in smoothing out my idle and raised my idle speed from 650ish RPM to 700ish RPM. Right where it should be.

[MENTION=102449]Kanoe[/MENTION], thanks for response. Ya I know, crappy cell phone video. They didn't give me a print out, so I took it back and asked them to verify. They said they were positive of work, and that it was probably the timing chain. Not happy with that, I brought it home, removed the valve cover (next day), and checked all clearances as per FSM. I found 3 valves (all exhaust) still out of spec, and 1 grossly out...measured .020...yikes. So I bought the specail tool and the correct shims and replaced myself. I really wish I would have just done the job myself. I'm no mechanic and I had no problems measuring and replacing shims. Now all valve clearances are within spec (in fact, all right in middle of spec).
Before valve adjustment. The engine did not have the 'tapping' sound.

Also, cleaning TB and IAC did help with idle speed. It now idles at 700.

Thanks

Durwin

 

[St Runner]

The 3RZ is going to be louder after valve adjustment. As it wears the valves, esp the exhaust get tighter and quieter until there is no adjustment left and you start mushrooming your valves. When you bring them back to spec they are looser and noisier. If they are in spec you are fine. In general it is a noisier engine than the 3.4, I have both

 

[owyheerat]

The 3RZ is going to be louder after valve adjustment. As it wears the valves, esp the exhaust get tighter and quieter until there is no adjustment left and you start mushrooming your valves. When you bring them back to spec they are looser and noisier. If they are in spec you are fine. In general it is a noisier engine than the 3.4, I have both

[MENTION=124742]St Runner[/MENTION], good insight. That makes sense, but I never would have thought of it.

Thanks

Durwin

 

[eurasiaoverland]

Does this sound normal for a 3RZ? Shared album - Google user - Google Photos

Some info. I bought this 99 4Runner in Jan of 2014 with 197k, it was in good condition, but had a slightly rough idle (engine would 'wobble' side to side ever so slightly). It ran fine and got good MPG, no codes and it never stalled or hesitated. The idle annoyed me, and I didn't know if it was something that could cause premature engine wear. I went through and changed all fluids to Redline synthetic, replaced plugs and wires, PCV valve, cleaned throttle body, IAC, MAF, etc. This did not fix rough idle. I drove it like this for 18 months and 12k. It seemed to be getting a little worse, so I took it to a local shop, and they said the valves needed to be adjusted. The valve adjustment fixed the wobble, but now it is louder than it used to be, and I'm not sure if this is normal for the little 4 cylinder?

Any info appreciated.

Thanks

Durwin

I just fixed exactly that noise. On the exhaust camshaft there is a spider gear. If someone who does not know what they are doing works on the engine, they may forget to lock the tension on the spider gear before removing it. That is what the previous owner did on mine, and I continued the mistake. Check the FSM for details on how to set it (Toyota call it a camshaft sub-gear). My engine went from sounding like a diesel to being amazingly smooth and quiet, really transformed it.

Hope this helps.

 

[SaulG]

1) Camshaft gear spring (out of position / broken ?? ) rare but has happened
2) Camshaft sub-gear
3) Wave washer

 

[eurasiaoverland]

Nothing is broken, you just need to set the preload on the sub gear by tensioning it and holding it in place with a bolt that runs into a specifically designed threaded hole in the main gear. It is there to eliminate backlash between the gears, and therefore noise.

Take a look at this excellent video, 20:35 in. It's a 5VZ but the principle is exactly the same.

YouTube

EO

 

[owyheerat]

Nothing is broken, you just need to set the preload on the sub gear by tensioning it and holding it in place with a bolt that runs into a specifically designed threaded hole in the main gear. It is there to eliminate backlash between the gears, and therefore noise.

Take a look at this excellent video, 20:35 in. It's a 5VZ but the principle is exactly the same.

YouTube

EO

I just fixed exactly that noise. On the exhaust camshaft there is a spider gear. If someone who does not know what they are doing works on the engine, they may forget to lock the tension on the spider gear before removing it. That is what the previous owner did on mine, and I continued the mistake. Check the FSM for details on how to set it (Toyota call it a camshaft sub-gear). My engine went from sounding like a diesel to being amazingly smooth and quiet, really transformed it.

Hope this helps.

Well, I recently pulled the head on my 3RZ to have a valve job done. I had a burnt valve on cylinder # 4.

Before removing the exhaust cam, I tried to put the 'service bolt' in the cam gear but could not get it to align. I remembered back to when I had the (above mentioned) local shop adjust my valves (which they did a sh**ty job of and I had to re-adjust), they had to have pulled the cams rather than use the SST to remove shims and they could not have set the pre load on the cam gear by inserting a 'service bolt'. The shop I took the head to was able to align the gears and insert a service bolt and I was able to install the cams (with the bolt in place).

I plan to put it all back together this coming weekend (if work schedule allows) and hope that it runs much quieter (and stronger... no burnt valve) than before.

So all that said, to say, You are both correct. And no more 'local shops' for me. I'll do it all myself.

Thanks

Durwin

 

[eurasiaoverland]

Great to hear. You'll be delighted by the reduction in noise

Did you see any wear on the camshaft gear teeth? Mine had polished surfaces but nothing that looked unusual to me for a 200k engine.

Good luck,

EO