1991 4 cyl valve question

If you have a '91 Camry, it should have either the 3SFE (roughly 2 L) or less likely the 5SFE (about 2.2L). I dont know of any other engine used in these cars. Its possible they may have a different engine in a car sold in less affluent countries, but I doubt it very much.

Both these engines are similar except for capacity ( bore and stroke) and other small changes. The valve lash is adjusted by selecting the right shim for each valve. The shim sits on top of the cam-follower, in a special recess It requires a good mechanical ability and special tools to do this job. Your mechanic was wrong when he said they use hydraulic lash eliminators.

Unless the engine has loud valve-train noise,..it's safe to leave them alone.

Jason

They do not have hydraulic lifters - the lifters are solid, but due to precision engineering and design, they rarely require adjustment - Toyota still recommends you check them, though, just that generally they're always fine. The four valve design means valves are lighter, and the overhead cam means the valve train is very light - only a lifter moves, plus they're at the bottom of the top of the head, so always bathed in oil.