Anyone adjust 2UZ valve gaps? (1 Viewer)

[Jim_Chow]

Has anyone here adjusted the 2UZ valve gaps? It uses those little shims like on the 1FZ/1HZ. Valve gap inspection is listed as a 60K mi service item. On the 1HZ/1FZ, which also uses the little shims, gapping is at 60K intervals. The local lexus dealer here re-gaps at 60K mi (I think this involves removing both cams, right?).

 

[SWUtah]

Has anyone here adjusted the 2UZ valve gaps? It uses those little shims like on the 1FZ/1HZ. Valve gap inspection is listed as a 60K mi service item. On the 1HZ/1FZ, which also uses the little shims, gapping is at 60K intervals. The local lexus dealer here re-gaps at 60K mi (I think this involves removing both cams, right?).

Never heard of this being done on a Toyota V8. I think the dealer is just ripping you off. My FZJ80 didn't need to be adjusted after 135K miles.

 

[SINCITY100]

You do not normally need a "gap inspection" or gap adjustment unless the engine was run without oil or is having a valve job or head replaced.

Unless you have a VERY loud valve tap, noise or major component failure, the gap tends to stay within specs for virtually the life of the motor.

I really think you would be opening a can of worms if one allowed a Tech to go into a seemingly perfect running engine and do "adjustments" to the valves.

 

[Jim_Chow]

You do not normally need a "gap inspection" or gap adjustment unless the engine was run without oil or is having a valve job or head replaced.

Unless you have a VERY loud valve tap, noise or major component failure, the gap tends to stay within specs for virtually the life of the motor.

I really think you would be opening a can of worms if one allowed a Tech to go into a seemingly perfect running engine and do "adjustments" to the valves.

Yeah, that's what I figured. This was the attitude of the indep. toyota mechanic who did the tune-ups on my vehicle in LA. He'd listen to the engine first, then decide if it sounded like the valves were out of gap.

 

[SWUtah]

Unless you have a VERY loud valve tap, noise .

I learned with my 80 series that with a shim the engine gets quieter when it gets out of adjustment, loud is good. When it gets quiet that means that you could burn a valve. With my 80 at 100k check (which they recommend with the 80's not the 100) my 80 was within spec and showed no wear. I never plan on checking my 100.

 

[2001LC]

Thought I'd bump this thread to see if in the ten years since, anyone has checked gap or found valve adjustment necessary?

My MPG has been dropping over the years, just looking for possible causes.

 

[TXLX100]

Never heard of it being done on this engine. Mpg could be a lot of things, ethanol content in fuel, O2 sensors, throttle body, MAF. You could check the compression on the engine, but unlikely any issue unless the MPg is way down.

 

[thegreatgazoo]

After I bought my LC at 120K miles, I asked Slee to check the gaps because the original owner never had it checked. Clearly I was new to the LC and Slee talked me out of the idea of doing this expensive and unnecessary check. What an honest shop!

 

[2001LC]

Never heard of it being done on this engine. Mpg could be a lot of things, ethanol content in fuel, O2 sensors, throttle body, MAF. You could check the compression on the engine, but unlikely any issue unless the MPg is way down.

I've dealt with all you've suggested except compression. What sort of drop and variance between cylinders should I expect to see in compression?

After I bought my LC at 120K miles, I asked Slee to check the gaps because the original owner never had it checked. Clearly I was new to the LC and Slee talked me out of the idea of doing this expensive and unnecessary check. What an honest shop!

Slee always has given me good advise as well, good crew & rep.

The 2001 scheduled maintenance guide recommend checking engine valve clearance at 60k mile.

What I'm wondering is if we have at least a small sampling of owners that have checked?

Be interesting to see what changes in compression and valve gap are being seen at various mileage points?

 

[TXLX100]

@2001LC I don't know the compression specs on this engine, but I'd expect cylinders to be within 10 PSI of each other. There is a member on here @ponytl i believe that has replaced some engines, I bet he'd know what to expect, or Google. What is your mpg now and what was it, is your LC stock or modified?

 

[2001LC]

@2001LC I don't know the compression specs on this engine, but I'd expect cylinders to be within 10 PSI of each other. There is a member on here @ponytl i believe that has replaced some engines, I bet he'd know what to expect, or Google. What is your mpg now and what was it, is your LC stock or modified?

My MPG is pretty good but was great for our 100 (older style transmission & pre VVT). Now at ~160k miles I'm getting MPG's of 15.69 summer & 14.56 winter, pre 100k miles was 16.72 & 15.49 respectively, all stock. These are long term average taken by tracking millage and gallons of gas per tank. I have a lite foot, rarely use AC or cabin fan, run tires psi +2 above rec, removed third row day one and well maintained.

 

[TXLX100]

Sounds like pretty good MPG to me!

 

[2001LC]

It is pretty good MPG, but declining.

Regardless, I'm just fishing for data.

 

[ponytl]

I think the MPG is better than anything I see I'm always between 12.9 and 15 max and i check every tank full...

I have never been into the valve train of these 4.7 engines... I could do a google search so what I'm about to assume is not just stupid... but these engines in normal use are so under stressed and over built... small displacement, long rod, med stroke, med bore, 4 valve per cylinder, relatively small rpm operating band ... there is zero extreme in it's design... but all things that move /rub have to wear... the seal of the cylinder, the seal of the valves, the tension in the valve springs, maybe some wear in the valve lash... everything in the injection system, the O2 sensors... I just don't see any ONE thing in normal wear that could make the performance and MPG drop in a normally operating engine... but several small things could easily affect the performance and the MPG... even things outside the engine... the torque converter? anything in the drive line that is creating more drag will tax you MPG... even the weight and volume of oil in your differentials can have an effect ... and don't forget Obama told us that we could increase MPG by 20% just by inflating our tires...

 

[2001LC]

I think the MPG is better than anything I see I'm always between 12.9 and 15 max and i check every tank full...

I have never been into the valve train of these 4.7 engines... I could do a google search so what I'm about to assume is not just stupid... but these engines in normal use are so under stressed and over built... small displacement, long rod, med stroke, med bore, 4 valve per cylinder, relatively small rpm operating band ... there is zero extreme in it's design... but all things that move /rub have to wear... the seal of the cylinder, the seal of the valves, the tension in the valve springs, maybe some wear in the valve lash... everything in the injection system, the O2 sensors... I just don't see any ONE thing in normal wear that could make the performance and MPG drop in a normally operating engine... but several small things could easily affect the performance and the MPG... even things outside the engine... the torque converter? anything in the drive line that is creating more drag will tax you MPG... even the weight and volume of oil in your differentials can have an effect ... and don't forget Obama told us that we could increase MPG by 20% just by inflating our tires...

Hello pony, thanks for stopped by.

You may find this Interesting concerning MPG; I believed low altitude (sea level) contributed to better MPG, but recently learned I had that wrong...duh. The fuel system reduces gas throughput to compensate for less air density (O2) at high altitude. This may be why you've not seen MPG like what I'm getting here in the mile high city. That and I rarely use AC or cabin fan, love that seat heat.

I guess with these bullet proof over designed engine it's no wonder I've not found any data on valve gap or compression. Even with the 2UZ-FE ~18+ year history and factory recommendation to check every 60K miles it's just not done, other than by sound. Concerning; clicking sound will be a louder if loosen (widening gap), but we'll not hear if tightening which is more likely to happen. If my valve cover gasket(S) ever need replacing I'll check then report back here.

I totally agree, all these items you've listed will contributed to decline in MPG, basically age. I've address most all of them including trying different viscosities/brands of lubes. My most notable drop was when I switched to all Mobil 1 synthetic, which cut MPG by ~1%. Mobil 1 full synthetic MV ATF was about half of that, as it is a higher viscosity then Toyota's old and newer ATF's. But I've elected to stick with the M1 synthetic line as do like for everything but MPG.

The only things I've not addressed is the: valve clearance, compression, coils and the fuel injectors (other than and annual can of 44K). These engine are well engineered, far better than the old ford & GM big blocks. My heavy duty mechanic work was in the 60 & 70 with muscle cars. Those engine where ready for rebuilding by 50K/100k miles. My favorite was a GTO 400CI, 4 on the floor with a six pack. I ported & polished the heads, use over sized rings, installed high lift long duration cam, thinner head gaskets and high performance distributor, plug wires & coil and added exhaust headers with caps. Started with balancing crank and finished by blue printed engine on reassemble. I also found it necessary to adjust valve clearance gap every 2K mile for peak performance (hydraulic lifters with push rods). The gap or lash was and easy but sometimes messy job done while engine running.

Obama, well my test yield far less than 20%, ~1/2 of 1% improvement in MPG by over-inflating tires. But hey that's got to be one of the most honest statement he's made in 7 years.

 

[AJax33]

Hello pony, thanks for stopped by.

You may find this Interesting concerning MPG; I believed low altitude (sea level) contributed to better MPG, but recently learned I had that wrong...duh. The fuel system reduces gas throughput to compensate for less air density (O2) at high altitude. This may be why you've not seen MPG like what I'm getting here in the mile high city. That and I rarely use AC or cabin fan, love that seat heat.

I guess with these bullet proof over designed engine it's no wonder I've not found any data on valve gap or compression. Even with the 2UZ-FE ~18+ year history and factory recommendation to check every 60K miles it's just not done, other than by sound. Concerning; clicking sound will be a louder if loosen (widening gap), but we'll not hear if tightening which is more likely to happen. If my valve cover gasket(S) ever need replacing I'll check then report back here.

I totally agree, all these items you've listed will contributed to decline in MPG, basically age. I've address most all of them including trying different viscosities/brands of lubes. My most notable drop was when I switched to all Mobil 1 synthetic, which cut MPG by ~1%. Mobil 1 full synthetic MV ATF was about half of that, as it is a higher viscosity then Toyota's old and newer ATF's. But I've elected to stick with the M1 synthetic line as do like for everything but MPG.

The only things I've not addressed is the: valve clearance, compression, coils and the fuel injectors (other than and annual can of 44K). These engine are well engineered, far better than the old ford & GM big blocks. My heavy duty mechanic work was in the 60 & 70 with muscle cars. Those engine where ready for rebuilding by 50K/100k miles. My favorite was a GTO 400CI, 4 on the floor with a six pack. I ported & polished the heads, use over sized rings, installed high lift long duration cam, thinner head gaskets and high performance distributor, plug wires & coil and added exhaust headers with caps. Started with balancing crank and finished by blue printed engine on reassemble. I also found it necessary to adjust valve clearance gap every 2K mile for peak performance (hydraulic lifters with push rods). The gap or lash was and easy but sometimes messy job done while engine running.

Obama, well my test yield far less than 20%, ~1/2 of 1% improvement in MPG by over-inflating tires. But hey that's got to be one of the most honest statement he's made in 7 years.

Bumping this up. Researching valve clearance adjustments. I am due for new valve cover gaskets. My independent Toyota shop quoted me $570 for new gaskets with adjustment. For just the gaskets, they quoted $370. I'm thinking it may be worth it just for the peace of mind. I may be able to report back on mpg afterwards too, although I run 285/75/16s KO2s and my mpg is around 13-14. I have an '01 with 210K miles. Thoughts on going with the adjustment? Yay/nay?

 

[camino70]

$370 seems too much for valve covers, they're pretty simple to replace. For the extra $200, they're probably just measuring valve clearance. I'd imagine it to be much more to pull the cams and adjust the shims.

 

[AJax33]

$370 seems too much for valve covers, they're pretty simple to replace. For the extra $200, they're probably just measuring valve clearance. I'd imagine it to be much more to pull the cams and adjust the shims.

Yeah, I thought so too, but I care too much for it to let myself work on it and fxxx it up. If only it wasn't my DD...

 

[camino70]

Can I talk you into trying the driver's side, eight bolts and ten minutes? If it's leaking now, you may only need to snug the bolts up, they have a tendency to back out. If snugging doesn't work, I can't imagine you trying the gasket yourself would make anything worse.

 

[2001LC]

@AJax33
I'd love you too post the data (measurement on the gap of each valve) here. Based on information you may have seen just posted in '98 Engine Noise Diagnosis by @fj55-100 it's good idea at 180K miles when timing belt is done.

But @camino70 has given you a good suggestion, re-torqueing the valve cover bolts first. I found two out of two sets of cover bolts loose just last year. The third I didn't check as a shop had just replace gasket, but I probably should have. Re-torqueing is a $40 job ($20 for a 1/4 torque wrench and $20 for the sockets set to match) and 10 minutes. Torque is 53in.-lbf, note that is inch foot pound, ergo the little baby 1/4" torque wrench. Make sure to uniformly tighten the bolts in several passes.