halfstep

Hello everyone.
I am working on my dad's 88 toyota pickup. He bought it new and it is still near new. He has babied it and taken great care of it. It has 90,000 miles on it. I replaced the clutch and pressure plate. I replaced the rear and front oil seals. The valve cover gasket was leaking a bit so I replaced it. Since I had the valve cover off, I thought I would adjust the valves. I went through the proper procedure and did it while it was at operating temp. I adjust the intake at .008 and the exhaust at .012. Now it really rattles. I went through again and got the same result. It is excessively noisey. I had a friend who is a mechanic come by and we got the same thing.

I have read where some set it cold at .007 and .011. But isn't that going the wrong way? Instead of a smaller gap cold, shouldn't the gap size increase? When the valves are hot, they get longer making the gap more narrow. I set the gaps when hot and when it cooled completely off, I checked the gaps and the intake was .014 and .025 for the exhaust. So why would some reccommend the cold setting at .007 and .011?

What am I allowed to set the gaps at while hot? Is .006 and .010 okay ot too tight?

Thanks for your help.

Inferno451

I'm no expert, but i believe the whole point of the valve clearance in general is so that when the valves heat up and expand, there is still no contact between the cam lobe and the rocker arm so that the valve can completely close. It seems like it's a general consensus that the factory specification is a bit loose if you want it to be quiet. Just as an experiment a few weeks ago, i got the engine hot as heck and adjusted the valves by feel so that there was just a bit of clearance, without a feeler gauge. I could hear it more than feel it. I figured if the engine was hot, the valves wouldn't expand any more anyway, so as long as there wasn't contact when they were supposed to be closed, i should be fine. Put everything back together and i kid you not, that engine was SILENT AS THE GRAVE. NO clicking, and it had 300k on it, and as it turns out, a badly worn camshaft and rocker arm. I ran it for about a week like that and it ran perfectly. Only difference i noticed was that the engine was so quiet. I couldn't tell you how tight i set them, but it was probably a pretty close gap. My personal feeling is that the factory gap is good if you want to MAKE SURE the valve will NEVER stay open if the engine get's really hot, but as soon as i get my engine rebuilt (not caused by valves) i'll be setting them tight. I think .007 and .011 cold would be JUST fine. Again, i'm no expert, and there are people on this forum with much, much more experience than I, so take my advice with a grain of salt.

4Voigt's

set valves at operating temp. intake .008 in. or .20mm exhaust .012 in. or .30mm and don't over torque valve cover bolts it can cause the valves to make noise too. valve cover torque is 52 in-lbs.

pruney81

I have played around with setting them at .008 in. .012 ex. hot and 7 and 11 cold and I have had better luck doing them hot to the specs the manual suggests. You just have to make sure to get it hot(operating temp, I drive around the neighborhood) then take off all hoses, valve cover etc. really fast and the feeler gauge should have a significant amount of drag when pulling it in and out and you should be good to go.

Yeah, and just barely snug those valve cover bolts down or it'll rattle like crazy.

If done properly while hot the motor will stay at .008 and .012. You have be careful to hold the gauge in there real snug while tightening the adjusting screws. It took me a few times of messing around with it to get the process down. Now I can adjust my valves in no time. Just take your time and be patient and you'll get the hang of it.

superex87

I was under the impression that in the service manual there is a typo, the valves are supposed to be adjusted with the engine cold. when you adjust them with them hot, by the time you get to the last set, the valves have cooled of a good bit throwing out the adjustments. there is no way realistically you can adjust them accurately when they are hot because they begin cooling instantly.

GranVille-4crawler

subscribed. I'll be doing a valve job in the coming weeks. fill me with knowledge!

pruney81

I have adjusted mine hot to .008 in. and .012 ex. and if you can do it fast enough they will stay there. I know this because after I adjusted them I went back and checked them cold and there wasn't any noticeable change in the clearances on the feeler gauge.

I have had success with adjusting mine hot I just had to practice 2 or 3 times to finally get it right. Just my experience with my 22RE.

halfstep

Thanks for the reply. I adjusted mine hot at .012 and .008 and got it done quickly. But when it cold off, I get .025 on the exhaust and .014. It seems to me when people set the .007 and .011 cold, they are actually going the wrong way. When the valve get hot, it grows in length so when you set it hot at .008 and .012, when it cools, the valve gets shorter and the gap grows.

The truck is actually a little noiser now after adjusting the valves. But that is expected. As a vehicle gets broke in and gets several miles on it, the valve gaps get more narrow. When an adjustment is done, the gaps are reset back to spec. These adjustments will widen the gap.

I just am trying to understand the concept of setting them cold at .007 and .011. When the engine gets warm, the valves will grow and narrow the gap even more. It seems the cold adjustments needs to be wider that the hot adjustment to allow for the lengthening of the valve.

Am I seeing this wrong?

pruney81

All I know is I adjusted mine cold at 7 and 11 and while the truck was quieter it had a miss at idle. I adjusted hot to 8 and 12 and now it idles perfectly and I haven't had any issues with it since.

worshipmentor

iTrader: (3)

Just did a HG job and of course I wanted to adjust the valves. I set them like the FSM says at
.008 & .012 cold and it ticks like an old chevy with collapsed lifters!!!!!!
Seems to me that if i were to reduce that to .007 & .011 COLD it should help but maybe i'm just no good at adjusting valves (been driving hydralic lifter V8's for too long!)

superex87

The reason you adjust them to .007 and .011 COLD is so that as the valve gets hot and expands the clearance becomes LESS. the tighter the clearance the more valve lift/duration you get. I.E. better performance/ gas mileage. And less noise as well. If you have ever worked on an older Honda that has the same valve train design the gap values are identical. The goal is to get the gap as tight as possible without holding the valve open continuously.

goodyota

okay, this thread is not a new one but i would like to add...I do MY valves to .007-.011 @ OP TEMP and it is MUCH quieter than 8-12. seems crazy but i have seen the difference and havent had any problems. good luck

AJ Tarnas

Could we please just call Japan already and find out if the FSM "hot" spec is a typo? Should it actually be "set cold"? I can't visualize what's really happening with the valves in the engine...

What is really needed in this situation -- a slight .008"/.012" gap at operating temperature (meaning roughly 2x or 3x that when cold, the valve stems shrinking away from the rockers), or almost no gap when operating (the valves expanding to be in almost continuous contact with rockers), and .008"/.012" when cold?

benja455

Tag for later. Plan to do an adjustment very soon.

waynesworld

I have adjusted my valves a couple times after new engine was installed,i think im gonna try this next,thanks pruney

talonfstone

subbed! I am doing mine this weekend and need to know the whole process! if yall can help.

Inferno451

Search. It's all over the place.

skebe22RTE

i actually think this idea is ingenious... and i'm not being sarcastic! it makes sense because if you're doing it hot, by right, it really shouldn't expand any more than it already has.

it sounds scary to do it this way, so i will try something that someone else posted on a different subject in this same forum, he claimed to have adjusted it when hot with .006" on intake and .010" on exhaust and end up having a nice and quiet engine. If you think about it and if you've adjusted the rockers before, then you'll know that once you stick the feeler gauge in, adjust the rocker, and pull it out, there is still a significant amount of space because you can still shake it up and down.

also, there's really no such thing as over torquing the valve cover, there's TONS of space between the valve cover and rocker arm, if there wasn't a whole lot of space, and you over torqued it, you'd break holes in the cover...

so if i have a chance this weekend, i'll try it with .006 and .010. if i don't forget, i'll post my findings, thanks for the feedback guys! really helpful!

millball

Just because the engine has come up to operating temperature, does'nt mean that the valves are hot. Not by a long stretch.

When an engine is operating under load at several thousand RPM, the exhaust valves operate at red heat. In other words, near 1000' F. Just a minute, at idle speed is enough to cool them by several hundred degrees.

The only cooling that they get is during the time that the valve disc is tight closed against its seat.

Anybody who values their machine, will disregard inferno451s' set by feel scheme and set their valve lash to the FSM specs.

Perfect silence is not to be desired when dealing with solid valve-train engines of any sort.

Any exhaust lash clearances that have been set, either with the engine at ambient temp (cold), or with the coolant at operating temp will be even less when the engine is operating at speed, and under load.

skebe22RTE

well, inferno did say he's no expert, so it's not like he's forcing us all to follow what he states, just merely a suggestion that i'm actually willing to take...

i actually adjusted them ONCE and it was SO quiet that i loved just listening to the engine at stop lights... i mean i would shut the radio off JUST so i could listen to it haha, so i know it's possible, and i'm shooting for that