[kacar]

Hi all. I know the topic has been discussed before, but also could not find anything specific regarding valve adjustment. No videos or anything. Maybe a couple of 3sfe videos.
I have read a few times that if you have no problem, you should not touch it, even read somewere that the valves on this engine almost never require adjustment (would explain the lack of information and diy videos).
Should mention that i have no problems eather, runs smooth, no noise, it is one of the quietest engines i know. In all manuals it says inspect and adjust every 96000km. I've done more than that, since i have it. Have not checked them, i suspect previous owners did too. It has arround 550000km, by my estimate.
The service company i worked in, a few years back, had a history of it for a head gasket job and head reconditioning (but not full), some 16-17 years ago, and half the mileage.
Just curious, i have a TB job in near future. Should i even bother ispecting valves?
As i said works like a clock on petrol and LPG also. Never had engine problems (knock on wood), except the normal oil pump gasket leak.
Cheers


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[93celicaconv]

Your 5S-FE engine has a shim that was selected at the factory to give you the proper gap between the lifter and the opposite side of your lobe on your cam. If a good quality oil has always been used and oil changed at recommended (or sooner) intervals, and if the head doesn't have a sludge buildup problem, it is very rare there will be observed sufficient wear of the shim to cause you to want to be concerned.

It is possible your cam lobes may have worn slightly over this time, and that wear isn;'t picked up be checking valve clearance (as you are checking on the opposite side of the cam from where the lobe is).

My opinion is if your car is running as you say it is, there is more risk to all the work involved to do a valve clearance inspection that there is benefit. The next time you need to change your valve cover gasket and/or your spark plug tube seals, that would be a great time to check your valve clearance. Most shops that need to work on heads to that anyway, as it is easy to do if you take your valve cover off.

There is a table for what your measured shim size is and your clearance reading, which if not OK, will tell you want new shim you need to get. I wonder if new shims are even available for that engine anymore. Most likely these shims for that particular engine aren't stocked in all sizes at your Toyota dealer. Just so you are prepared if you do check them and something is off, it may be a challenge to get new shims of the right size to replace these days.

 

[Old Mechanic]

Similar to some motorcycles but clearance range is large. On my 1973 Alfa GTV 2000, I measured .001 wear at 100,000 miles after lash was set, by me, when the cylinder head was off, which is the best time to do the adjustment. Consistent throughout the valves. Valve seat recession is the reason for the adjustments closing and they do so very gradually, so no recommended adjustment periods. Good time to check is when you do valve cover gasket replacements for leaks.

 

[93celicaconv]

Great point, Old Mechanic. You are right - generally the valve lash gets smaller due to wear between the valve and seat. In these situations, the engine will get quieter (reduced valve noise) with the ramification of leakage between the valve and seat - which on an exhaust valve, will start the process of burning the valve and reducing cylinder compression. But like you said, this wear is gradual. As an alternative to getting the correct thickness of shims, one can also adjust valve lash that is getting tight by removing the valve and taking some material off the stem - even a new valve can be handled this way to get the right valve lash - so new shims aren't the only way to get valve lash adjusted properly.

 

[BMR]

I wonder if new shims are even available for that engine anymore

I just went thru this on the 3S-FE in my ‘98 Rav4, here. I had no trouble getting the shims I needed from Toyota. FWIW, it takes 28mm diameter shims, which are used on non-Toyotas too. But there aren’t a lot of aftermarket choices available. I tried Regis, but they only had two of the nine I needed, so the shipping cost made them more expensive than Toyota’s.

 

[ghettosled]

I too don' think there is anything to really adjust or shim. Pic of a RAV4 head, but is similar to the Camry:

Though if you were to go this far, look at the valve and valve seat mating surfaces. Either compression check or leak down test to verify everything is good. In the case of this RAV4, this was one of those stripped head bolts that caused the head gasket to blow, but in the process found some leaking valves. Little difficult to see in the photo, but each area was filled with gasoline to the machined surface but cylinder 3 had a small leak (cylinder 4 had the coolant leak).

 

[93celicaconv]

Attached is the valve clearance check process for a 5S-FE.

In ghettosled's response, the valve should be expected to seal (unless they are burnt, cracked, or other) if the cam is not in place. When the cam is in place, and there is no valve clearance, that will prevent the valves from closing properly just because the cam is in and the valve seal surface as worn a bit to cause it to go ever slightly deeper when closing. That is why valve clearance should be checked whenever the valve cover is replaced - to verify the valve clearances are still when the specified tolerance.

 

[kacar]

Well thanks for all the info. As someone said, if no obvious problem, it will do more bad than good to adjust them. But for sure i will check the gap on the next valve cover gasket replacement, and it might be soon.
After all it is a proven valvetrain on this engines. Main concern was, because i also have an LPG unit installed many years ago, on newer toyota engines (especially ford engines for eu models, which actually use mazda engines), valves are known to have problems with lpg, especially if no additional valve lubrication is installed. These older ones have no problem with it.
Cheers

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