saber

I've been reading conflicting advice about how to cure for this common ailment of the ''90-'94 models.

One camp says the valve clearances need to be adjusted. Another camp says one or more valve lifters
has a problem and needs a repair of some kind or else the valvetrain could eventually lock up.

If the second camp is correct, can someone describe specifically what goes wrong with the lifters and how
to repair them? Thanks

RTIS250

iTrader: (9)

Well, they dont have lifters. There is a "bucket" or a cap, over the valve spring, on top of that is the adjusting shim, and on top of the adjust shim is where the cam lobe rides. What has been known to happen, is the stem of the valve wearing away the inside of the "bucket" and causing excess clearance between the cam lobe and shim. The first step that needs to be taken, is checking valve clearances. If one or more are excessively out of spec, then i would remove the cams and inspect each "bucket" for irregularities... Replace the worn "buckets" and perform a valve adjustment...

saber

Thank you very much RTCamaroSS. Your answer makes perfect sense; i.e. for a lasting fix, replace the worn bucket in addition to readjusting the valve clearance. And then change oil more regularly to reduce the potential for future wear (the ticking seems to develop in engines with an irregular oil change history)

lorenzo816

Okay guys, I think this is my issue.

original post is here

So would you recommend doing it yourself or take it somewhere to be done?

I'm not afraid of working on the Lex.
Well I'm scared to death of the timing belt change.
So if its anywhere near that... I don't want to do it.
But if it is just shy of ripping the engine into every little piece, I'll do it myself.

So how do adjust the valves - cams?

1992 LS400 170k

saber

lorenzo, checking and adjusting the clearances is fairly involved, but not impossibly difficult
and is not as complicated as changing the timing belt.

You'd need a factory repair manual to guide you and also need to order a $50 set of valve adjusting shim removal / installation tools. This website http://www.lexls.com/tutorials.html has tutorials that don't specifically cover valve adjusting, but do cover some of the component removal procedures necessary to gain access to the camshafts and valve adjusting shims.

My guess is a Toyota dealer would charge around $500 to adjust the valves and a Lexus dealer nearly double that, but some Toyota dealers will not work on Lexus's.

lorenzo816

Fellas, thanks again for the quick post.

I'm going to start to have to pay rent here, I've been here so much, lately.

I'm familiar with the lexls website, very good stuff.

I have a CDManual, I bet that will cover it.

But I think I'm going to try what THREXX has said here first.
Especially since I just dropped 8hundred, and saved my a@@ from spending 4k.
You should have seen the look on my wife's face. :-{
I promise I'll post Pics of the exhaust when I get under the car tomorrow.

After that, I will definitely check into the local Toy Stealer down the street.

Oh, and I just got laid off - right before Xmas, so the money is going to be tight from now on.....

- lo -

1992 LS400 170k - oh and I forgot - got the Michelins HydroEdge a couple of months ago - SWEET

saber

As as RSCamaro explained:

"What has been known to happen, is the stem of the valve wearing away the inside of the "bucket" and causing excess clearance between the cam lobe and shim. The first step that needs to be taken, is checking valve clearances. If one or more are excessively out of spec, then i would remove the cams and inspect each "bucket" for irregularities... Replace the worn "buckets" and perform a valve adjustment..."

So metal on metal wear is what caused the excess clearance in the valvetrain which in turn has led to the valve tapping noise. So no mail order $25 a bottle snake oil additive is going to solve the tapping problem. It's only going to help enrichen a snake oil saleman's bank account.

Monster mileage Toyota owners http://www.saber.net/~monarch/cole2.JPG don't use oil, fuel or coolant additives or aftermarket filters, spark plugs, etc., because they know the most risk free products to use are the ones that Toyota installed in their cars from the factory to begin with.

hyperopt

I would say doing valve adjustments is on par with changing timing belt. As for me, I prefer to do timing belt instead as one would not know what is entailed with the valve thingy unless one open and inspect kind of like a "box of chocolate" - you might find bitter-sweet taste underneath those covers.

saber

Found this excellent thread on valve clearance adjustments in the archieves:
https://www.clublexus.com/forums/sho...alve+clearance

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
LexusBiz