[danarello]

Greeting RAV4 World,
I took my 1998 RAV4 4D Automatic with 55K miles to my trusted auto repair shop. My vehicle just didn't have a sufficient amount of power, especially climbing hills IMO. I requested them to inspect under the hood and "please do a tuneup and valve adjustment if necessary." My mechanic found oil leaks contaminating the spark plugs and the wires. Work completed and car seems to have more power. I asked, "Did you find any valve clearances out of specification?" He replied, "Dan-because they were pucks, they never change." Does that make sinse to anyone here on the forum?
Danarello

 

[Dr. Dyno]

It means he never checked clearances.

 

[foxtherouge]

Like Dr Dyno said, mechanic didn't check valve clearance. At 55k your valves should very much so still be within spec though, unless there was a catastrophic failure. Oil in the spark plug wells was probably due to dried seals as they haven't been used much so that is a very easy fix.

 

[TomKatt]

I interpret the "puck" comment as hydraulic lifters, meaning the valves are self adjusting by oil pressure. As such, manual adjustment is not provided.

 

[Dr. Dyno]

I'm not familiar with a 4.1 engine's valve lash adjustment but do know many small four-cylinder engines use shims that the cam lobes ride directly on. Some of them as on the Fiats I used to work on are the size of maybe three quarters stacked up, thus the term "puck." True, the shims never change but the valve lash does but it's very unlikely in 55K miles.

 

[foxtherouge]

3sfe does not use hydraulic, it uses shims. Generally they last for a long time since they are not a high revving motor to begin with.

 

[Dr. Dyno]

3sfe does not use hydraulic, it uses shims. Generally they last for a long time since they are not a high revving motor to begin with.

And just to be clear it isn't the shims that wear but the valve lash can change as the valves themselves do so the shims need to be changed to different thicknesses to maintain the proper lash..
Most modern engines can go for years w/o the lash changing so it virtually never needs to be checked. One notable exception it the first generation CRV. The exhaust valves would burn by 100K miles unless the lash was checked periodically. Happened to my daughter years ago. The car needed a valve job at 100K, which of course her extended warranty refused to cover.

 

[LugNut]

3sfe does not use hydraulic, it uses shims. Generally they last for a long time since they are not a high revving motor to begin with.

Correct -- Description of how to check/adjust starts on page EM-4 of volume 2 of my 2000 FSM.

Fortunately, I kept my lifters, etc. in order, and they checked-out fine after replacing the valve stem seals many years ago ...