Hey All,

Well I finally had it with the ticking noise coming from the valves. This past weekend I finally dove in and attacked. The job was quite simple, very time consuming though. Took me about 5-6hrs to take everything apart (removing throttle body took the longest and hardest part of it). From there it was a matter of checking and rechecking the shims and spacing.

Then I ordered the shims, that took about 2 days. Another day to wrap it all back up, I took my time and cleaned everything up while I had the parts out. I did not have the special Lexus SST A/B gadget used to remove the shims, so I took out the exhaust camshaft to access the exhaust side shims. As for the intake shims, I lucked out, only one intake shim was out of range, and that was the last one on cylinder 7. So I just loosened the intake camshaft enough for it to give me clearance and reached down using compressed air and magnetic tool to pull out the shim.

In case anyone is looking into doing this project I'd say it is not too difficult. Just MAKE SURE to lay out everything in order, so you reassemble everything back correctly (especially when you are taking out the camshaft, bolts, and retainer). And definitly take your time doing it. If I had to do it again, I could probably knock it out in 10-12 hrs, but first time around I gave it a few good days.

Here is a list of useful part numbers I used in the job:

Valve Cover Gasket: 11213-50021 (Qty: 2)
Spark Plug Tube Gasket: 11193-15010 ((Qty: 8)
Valve Cover Bolt Washer Seals: 90210-07001 (Qty: 16)
Denso Platinum Plugs: 90919-01178 (Qty: 8)
Tube of Toyota Oil Pan/Valve Cover Sealant
Bottle of Toyota Antifreeze

You'll also need a good/accurate micrometer (I used a digital Mitutoyo micrometer) and a good set of feeler guages. That's about covers it.

THanks
Biz

 

good informative post. Did it help your engine run smoother also? you would think that it would, now that the valves are all perfectly adjusted, it might even help with power slightly? I am thinking of doing this sometime just for the preventative maintenence aspect of it.

 

Hey Boredguy77,

I started the engine only briefly, shut it down and waiting to do a oil change tonight to get rid of the junk that may have fallen into the valve body area. Have not test driven yet!

From the couple minutes I ran the car, it definitly sounds 100% better. No more tapping at all. The main tapping came from one shim on the driver side intake valve on cylinder 7. It was really off range, so now that it is back in range I should get full optimization from cylinder 7.

Aside from that intake, about 10 exhaust shims were right at the border range. I went ahead and replaced those as well to close the gap and curve any future shim adjustment needs.

I do not think I will see any performance gains from the exhaust shims changed, maybe a very slight (if noticable at all) improvement on cylinder 7 since the intake shim was changed.

The main satisfaction is NO MORE TICKING. God, that TICKING from the engine was driving me up the wall. On nice sunny days I would roll up my window just so I do not hear it. I also replaced the Bosch +4 plugs with the factory Denso's, so maybe that on top of the shims will give me some what of a noticable improvment.

NO MORE TICKING

 

I knew a performance gain would probably out of the question, I just thought maybe smoother power. But overall just the satisfaction of losing the ticking is enough.

 

Hey BIZ !!

Great post. this is probably a very common problem for high mileage SC's (mine ticks in just one spot) so that is great of you to post that. if you think of anything else that may be important to know in procedure or parts let us know !

(and next time take pics)

 

Hey Biz, how many miles does yours have? I'm guessing it's an SC400? I think I looked that up in a shop book and it called for something like 28 hours, so it sounds like you did a good job! And you saved yourself a ton of money!!! Doesn't Lexus recommend adjusting valves every 120k?

 

Hey Onelasttry,

My digi cam has gone to digi cam heaven. Sorry, but no pics. I did create a very useful template/document I used for keeping track of the shims, measuring distance, valve measuring sequence. There are three templates, first one (shown below) for measuring clearance and shim, second one for new shims ordered, and third one for new clearances after new/correct shims have been placed.

[IMG]C:\Documents and Settings\amirheb\Desktop\ValveAdjustment1.jpg[/IMG]

If any one needs them, let me know, I will email the files to you. I created them using Micrografix Draw, so the pictures are in .drw format. The files are best viewed in this format, however I can convert them to .jpg although you lose the picture quality. Worse comes to worse, I can mail anyone that needs them.

SweetSC400,

My car has 124K on it, SC400. I think it is good practice to check the valves at 120K, although working at a Lexus dealership in the past, I know that most cars with the ticking valves start somewhere in the 70/80K range. Some cars with well over 150K never have the tick, some cars with 50K have the tick. It's just one of those things, variant on many different factors.

My car originally started ticking with the previous owner at around 70K. They did a valve adjustment, but the previous owner said that the mechanic rushed the job and really did not take the time to correctly measure the clearances, the ticking was reduced, but not resolved completely. So I am thinking the ticking I was getting was probably the same valve that was not properly swapped out in the first place.

I would say if your jumping into this job, to measure, remeasure, remeasure, remeasure, remeasure. You have to get a feel for the feeler guages. You have to get a feel for what correct thickness/resistance you should be feeling when inserting the guages in the gaps (especially when dealing with .02mm differences between the guages).

Another word of advise, the manual says to torque the valve cover head bolts to 29lbs. I almost cracked my valve head trying to torque it to 29lbs. I got to about 18lbs before hearing crackling sounds from the valve cover. I spoke to several Lexus mechanics and they said 29lbs is way to much, that will easily crack the cover. I torqued all mine to 18lbs, and that really felt like over tightening. So I will have to keep a eye out for any oil leaks.

Thanks
LexusBiz

 

Lets try that again:

 

I give up

Here is the link for the template:

www.clublexus.com/gallery/showgallery.php?cat=500&ppuser=12298&thumb=1

 

How about this?

https://www.clublexus.com/gallery/sh...=12298&thumb=1



There- that's better

 

Would the measurements be the same for the LS400 as well?

thanks
eric

 

Thanks Tggoodrich,

I was starting to loose my mind!!!

Hey Eric,

I looked at the shop manual, looks like there is no difference between the SC and LS V8 specifications. The only difference I noticed was the procedures for removing the engine dust covers.

Thanks
LexusBiz

 

Word to the wise,

I ripped back into my engine this past weekend. Turns out I overlooked the correct reinstallation of the exhuast camshafts when I placed them back in. On the exhaust camshaft there are two bearings, one main bearing and one sub-bearing. Turns out the sub-bearing is spring loaded to keep pressure when connected to the intake camshaft (Lexus engineering genious )

There are tiny dots on the back side of the main bearing that should line up with the dots on the back side of the intake bearing. I totally overlooked this and lined up the bearings according to pen markers I had made on the front side of the sub-bearing. So when I took out the camshaft the tension on the sub-bearing turned the gear by one tooth mark. Thus, when I looked at the back of the bearing I saw that the dots were one tooth off on the bearings.

I really did not notice any difference in the engine, although I want to say the engine did feel a bit less responsive when I had the camshafts out of alignment. I ripped the camshafts back out and moved the sub-bearing back by one-tooth mark (reloaded the subbearing spring) and reinstalled the exhaust camshaft. Now the tiny dots line up on the back side of the exhaust and intake camshaft.

Definitly feel improvement on the engine responce. I also tightened the gas pedal cables to the throttle body a tad bit, so now I get accurate/instant power when I hit the gas.

Once you get into the engine, you'll know what I am talking about.

Thanks
LexusBiz

 

I have this same problem too and I'm sure that if there was a simple solution that someone would've already figured it out. But this question has always been bugging me about the valve shims. I'm aware that the ticking is caused by a gap between the cam lobe and the shim, so which is the one that is worn out? The cam or the shim? If it is the shim, then is there a specific design to it or is it just a flat piece of metal of a precise thickness?

Basically I am asking those questions because I have been quoted $90 for each shim, and was wondering if I would be able to simply flip the shim upside down and then put it back? Basically it is retaining the same thickness but providing a brand new surface for contact with the cam lobe.

 

great job, man. I have wanted to get mine adjusted cause the endless ticking is embarassing when people can hear it 15 feet away. The only valve that ticks in my engine is # 7 on the driver's side. Can I do the adjustment much faster if I only attack that particular cylinder (probably without touching the intake manifold)? Any suggestion is greatly appreciated.
Frank