"Poppy" exhaust sound....

Over the past few weeks, my Saturn SL2 has been developing an exhaust
noise.....it's kind of a rattly, poppy kind sound. It only occurs
under load (up hills, accelerating from a stop, and similar).


I'll level with you....I'm OK with a wrench, but I know nothing about
diagnosing cars based on their exhaust sound. I got under it and
looked for an exhaust leak, but there was none I can find, and I'd
think that the sound would occur more often if it was......

My wife was describing the problem to her father (a mechanic) and he
suggested that the the lifters needed adjusting. I can kind of believe
that, but there's no clatter from the engine compartment, like I would
expect. I've noticed no decrease in performance, or mileage. It's also
a sight-unseen kind of a diagnosis, which I never completely trust.

Also, this car has hydraulic lifters, which I know almost nothing
about. I understand the principles behind how they work, but that's
about it. I'm guessing "Lifters need adjustment" for hydraulic lifters
translates into "lifters are sticky" but I just don't know....

hell, that might not even BE the problem.


So, any advice on this issue will be greatly appreciated.

Thanks for your time.