So I have some free time here at work and I'm paging through the AllData maintenance website and I come across Valve clearance adjustment information for the LS. Has anyone ever adjusted the lifters on these cars or checked the clearance?

Is it necessary?

 

Does your engine tick? If not, I wouldn't worry about it.

I think many on here with over 200k has never gotten their valves adjusted but I could be wrong.

I'm almost at 130k and it was dealer serviced until 100k. The dealer never recommended a valve adjustment. I'm sure they wouldve just because previous owner would pay for anything the dealer recommended without question.

 

I've never ever heard of a *UZ engine needing a valve adjustment outside of a tuning application (new camshaft, or a beastly N/A motor with a 9k+ redline). Toyota overwhelmingly uses a shim under bucket system and they're very slow wearing - the wear is proportional to the average engine speed and engine temperature.

These engines run at regular temperatures and very slowly. I'd be surprised if any of us spent considerable amounts of time above 2600 rpm. I wouldn't expect to have to inspect the valves until well after the third timing belt.

My Yamaha uses a similar system and most people don't adjust it until 80-120k miles on an engine that spins 5k on freeway and most of those bikes see redline (9,800 rpm) at least once per ride. Oh by the way, the inspection interval is 26k miles.

 

Yeah, I figured as much. My engine on the '01 is silent. I'm not concerned about the lifters making noise yet...Maybe in another 150K...

 

These engines don't have lifters they have shims and buckets. Here's a link that explains why manufacturers chose shim and bucket systems. Although this focuses on shim over bucket systems and our engines have shim under bucket setups which are similar but more of a pain in the butt to adjust.

 

The valves should only need adjustment if something changes their clearance such as a valve job, reground valves, new valves, or a new cam. A very slight ticking from the clearence in the valvetrain is normal. No clearance or a valve remaining slightly open is bad and can lead to burned valves. You can actually listen to your valve clearance with a long screwdriver or extension. Put one end on the valve cover over the valve you want to listen to and cup the other end to your ear with your hand.

 

That's not true, the shim is a wear item (actually, the entire system wears but you can bring it back into spec with shims). It wears slowly but it's a wear item. If you were to drive the car at 140 mph for 200k miles, I'd bet dollars to doughnuts that you'd have to adjust the valves.

 

My last one I traded in at 200k was just as quiet as when I got it at 50k.

 

Have you checked valve clearances??
If out of spec then have them shimmed. Not a do it yourself. Be sure and change camshaft seals

 

I understand that the shim is a wear item. As it wears valve clearance increases. The head of the valve and the valve seat are also wear surfaces but as they wear the clearance decreases. I'm guessing these come close to canceling each other out based on the fact that these engines don't need adjustment. All surfaces involved are hardened and I'd bet that wear is minimal even after 200k or more miles.

 

Yes, quite a few. The joys of flipping Japanese motorcycles. I helped out a friend with a beemer and it had a shim under bucket system. Shim over bucket, shim under bucket, it's all the same idea. I'm here telling people that it's very unlikely that any 3UZ needs the service unless its been driven 20k+ miles per year since inception.


Which one is it?

 

Both. The shims can wear but so can the valves, seats, etc. Adjustment isn't required on our engines.

 

Full circle back to whether valve lash measurements occurred...

 

My point was that the shims and other valvetrain parts are wear items because they are in contact with other parts. My experience shows that these items don't really show much wear in our application. My valve clearences were within spec at 112k miles when I pulled my heads for a gasket issue. The factory manual shows an acceptable tolerance of .004 in. Replacement shims are available in .0008 in. increments. Toyota doesn't specify a mileage when clearance should be checked or adjusted, only when the heads are disassembled and rebuilt. These engines don't live a very hard life when they spend most of their time around 2k rpms. Like was stated before I'm sure wear would be more of an issue at extended high rpms.

 

never ever heard of this being done on an LS. As a matter of fact, when's the last time you heard an LS engine tick? i wouldn't worry about it