3RZ-FE valve adjustment

So I had my local Toyota dealer check my valve clearance on my 99 3RZ with 174k miles recently. I told them that I wanted the valves checked and adjusted if necessary. I was having them replace the valve cover gasket due to a leak and figured they could do the work while the cover was off.

I got the truck back and all they did was check the clearance and nothing else (other than replace the gasket). I got the tech to give me a copy of what the measurements were. They didn't even pull the two tight shims so I can't even order the shims I need. I was a little pissed off about the whole situation. They just seemed like they didn't want to do the work.

My question is, are the exhaust valves tight enough to be a concern? How much is too tight? Don't worry about the lack of extra zero in the picture, the mechanic forgot to write that in.

Exhaust (spec .0010-.0014):
.0010 .0085
.0085 .0010
.0010 .0010
.0010 .0010

 

Tight on cylinder 2 but that could also be from not being 100% TDC on that cylinder as well.

That probably won't cause much difference if anything that cylinder would open the exhaust valves just a tad early.

Are you experiencing any issues?

 

The only issue is a rough idle that shakes the truck. The rpm is within spec but it definitely shakes more than normal and has gradually gotten worse over the last month.

 

My 2TR-FE does this while under load such as in traffic sitting at the light and standing on the brakes.
Mine too has gotten worse. I'm planning 4 new injectors soon because spark knock has gotten bad too. It's way too lean.

 

The reason why they did what they did is because the 3RZ valves wear loose. I talked to my dealer about having mine checked and he said that Toyota tells them that if they aren't ticking don't touch them. I also have a friend that was a Toyota mechanic for 25 years and he backed up what the dealer told me. I asked the dealer about a valve going tight and he said that it's not impossible but it would be highly unlikely. He also said it costs up around $1000 to actually get in there and do a full check and adjustment. I suspect your vibration at idle is something else. Whether or not those valves are too tight I have no idea. It would be better to ask a few other mechanics.

 

Exhaust valves 2 and 3 are way out of the range (gap is too much). I'm surprised they didn't feel the need to adjust those. At least it won't cause burnt valves (too small of a gap would do that after a while).

 

Those numbers are written wrong on the paper, notice the text that I wrote out above the picture. They are .0085" which are too tight. All of the exhaust valves are on the tight side of the range.

 

My understanding is that the exhaust valves tighten up over time, not loosen. This makes sense since all of mine are on the tight side or the acceptable range. Except for 2 and 3 which are too tight at .0085".

 

My bad, I didn't catch your correction. I'm surprised that a pro mechanic would make that type of error. Eventually, I'd get those valves adjusted, at least 2 and 3, or you may have burnt valves in your future ($$$$).

 

I'm just passing on what my dealer who I have found to be very honest and a former Toyota mechanic told me. I have heard of cases on this forum where valves have gotten tighter but they usually don't. One of these days I'm going to take mine in and have them get in there and check everything just to be on the safe side. The $1000 would be worth the peace of mind to me. I'll probably wait until I've got 200,000 on mine.

 

Pretty easy job to measure the valve clearances. If they're good, then no need to pay big bucks for an adjustment.

 

The dealer here quoted me around $400 to do the job but they would most likely have to have the truck multiple days in order to order the correct shims.

 

Yea the master tech I was talking too pointed it out immediately, but he wasn't the one doing the job. I will most likely have them put all of the valves back into the middle of the range once I can be without my truck for a few days.

 

Thats a good price, mine quoted around $700. However, that might not include the cost of each shim they have to order (around $10 each). With 16 valves, do the math. Hopefully, only 4 valves, or so, may need adjusting.

 

To unconfuse future readers (like me), the typed chart of measurements above the pic should prolly read (in inches)...

Exhaust (spec .010-.014)
Measured:
.010 .0085
.0085 .010
.010 .010
.010 .010

So yup, that would put 2 & 3 tight, and the rest at the low-limit of spec.
Hopefully these measurements were done with the engine stone-cold, if not would explain all being tight.

 

Past experience with pushrod valve engines had exhaust valves getting tighter I understood was due to valve-stem stretch.

So if true about these overhead exhaust valves typically loosening...
I assume would be due to wear of components and no valve-stem stretch?
Components like: cam lobes, valve stem tips etc.

 

On valvetrains where the cam lobe acts directly on the valve stem/shim/bucket, the clearance *typically* gets tighter as the valve recedes into the valve seat/cylinder head and there are no intermediate parts to wear. Typically it takes 150-200k miles or more for the clearance to become out of spec due to valve recession, assuming good maintenance and no engine abuse. Some engines have clearance still in spec after 300k miles or more, due to good maintenance and no severe use/abuse.

On valvetrains where the cam lobe acts on an intermediate part(s) such as lifters and/or rockers (e.g. cam in-block or SOHC), the clearance *typically* gets looser because these intermediate valvetrain parts (between the cam and valve) usually wear at a faster rate than the valves will recede into the valve seat/head. In other words, the wear of the intermediate parts cause the clearance to increase at a faster rate than the valve recession causes the clearance to decrease. I hope this make sense.

Someone please correct me if this is wrong, but it's been my general understanding for decades. And obviously, hydraulic adjusters render this description pointless.

Thank you thank you thank you.

 

DGXR that's a great explanation, thanks.
But as you mentioned "hydraulic adjusters", I read a little so now at least know the gist what they are and how they work.

But reading other sites re. the 3RZ-FE engine, came across this on Engine-Specs.net :

"The 3RZ-FE engine has four valves per cylinder: two intakes and two exhaust. ....
This engine does not use hydraulic lifters, so you need to adjust the valves clearances every 30,000 km (20,000 miles) of mileage."

20K is way more than my old air-cooled VW's...
But holy crap, I've never adjusted my 02 Tacoma's valves in 245K.
Am I ruining my engine, or are these guys whacked?

Recently at a general auto repair shop (all manufacturers), I asked IF I should have the valves checked/adjusted?
Reply was they only recommend checking/adjusting IF THEY ARE NOISY. $500 to adjust, so I passed.
Again, are they whacked?

Anyone recall what the factory service manual advises for when to check/adjust the 3RZ-FE engine valves?
This thread seems to be all over the map on this.

cheers

 

sometimes a check b4 a mechanic helps

a compression and/or leak down reveals much

either could reveal a diff cylinder than represented by valve clearance

at Ur mileage i pull the plugs & check again b4 i go back

 

As noted by others in this thread the valves will wear into their perspective valve seats resulting in tighter tolerances.