My 2005 Acura TL has 196,000 miles on it. It appears from previous service records that a valve adjust has never been performed. The car is running fine with no indications of any problems.


Is it necessary to do a valve adjustment if the car is not presenting any problems?

 

Lots of conjecture on this in the past. I guess the question is how long are you going to keep your TL? If it runs well and you plan on getting another 50-100K miles or so out of it, it might be worth the investment to get it done (should be ~ $250 or so if you have the shop do it since it requires some disassembly to get to the valvetrain). The manual says to 'adjust if noisy' but the issue is that valves that are tight won't be noisy and there's a risk of them getting burned. It's equally possible (but somewhat less likely) that despite the mileage, the valves may all be within spec.

Sorry to give more questions than answers.

 

For an eminently readable article about valve adjustments see this R&T article written by Rob Siegel:

If you can change your own oil, you can adjust your valves

Not that I recommend DIY, but the article may provide insight as to whether you need it done or not.

 

my car didn't need it but i had it done and the car runs much smoother. the shop charged me 285 including parts (some gaskets) which is a good deal. i DIY everything but for the valves and the 105k service i didn't want to mess with it

i would highly recommend it be done regardless if your valves are noisy or not.

 

What is the result of a burnt valve?

 

Burnt valve means that the valve won't properly seat, resulting in leaky compression, cylinder power imbalance (these two will eventually cause many other more serious problems), and ultimately a valve that is damaged past the point of adjustment. I did a valve adjustment on my TL when it was at about 50k miles and the valves were OUT of spec. Have it done before a more serious issue is created.