99 Camry 4 cyl 60K service

I have never had the shims adjusted in 185,000 miles on my

Replacement of platinum spark plugs is called for at 60,000 miles. Not a bad idea to change the valve cover gasket also - usually seepage is occurring by 149K miles, and it's a fairly easy procedure on the 4 cylinder. When the valve cover is off, it is a simple matter to check the valve clearances. Only takes a few minutes with a thickness gauge. Then, if needed, they can be adjusted by replacing shims - but if oil changes have been kept current, this usually is not necessary. Good idea to check the clearances though, just so you know they're ok. While you're there, not a bad idea to change the PCV valve and grommet also. PCV valve is inexpensive and simple to change, and by that mileage the grommet is usually hardened and leaking slightly. Even easier to change when the valve cover is off, so any broken fragments fall "out" instead of "in". Guess there's always something else. While the valve cover is off, I'd also change the distributor O-ring to stem incipient seepage. Don't know what a dealer would charge, but the distributor is only held by one bolt. Changing the O-ring is simple. Then you just need to check the engine timing. I suspect many techs just make a mark, but the timing should be re checked - only takes a moment. Also, at close to 150K miles, I'd be changing the distributor cap, rotor and spark plug wires as preventative maintenance. You should be using the stock wires and they are more costly that the other items, but last a long time. Nonetheless, mine were creating a mild miss at around 90,000 miles. Didn't notice it much while driving but the resistance tested infinite and there was some shorting way down in the spark plug tube where you couldn't see it. Of course, if you don't mind the oil leaks, you could just figure the valves are probably good and skip everything. My platiunum plugs were still at the original gap at 60,000 miles, so conceivably they could go longer, too. Depends in some measure on your maintenance philosophy. I like to keep everything in good condition. Small defects can be cumulative, where the overall condition declines or is kept up.

Thanks Robmurr and Daniel. I spoke to an independant Toyota mechanic shop, very highly rated in my area, and he assured me that the valve shim adjustment is unnecessary at this mileage. Also his total cost was about $100 less than the dealer. I will be cancelling my appt. with the dealer.