ticking noise diag help.

[a.graham52]

my 135k LA1 has a couple ticking/tacking noises. when i bought the car i put head gaskets in it and removed 6 gallons of empty coolant bottles from the trunk... any who at cold start i have some tacking noises which im assuming is piston slap from cold pistons. but going down the road i can hear a ticking noise if i drive by a guardrail or something. at about 2500-3750 rpms i can hear a ticking/tacking noise that has about the same frequency of an exhaust tick. more prominent on the passenger side. windows have to be down to hear it though. my question is how i could daig this without throwing parts at it. oil lights never one, changed the oil at 3k, this last oil chagne i put a qt of lucis in the oil and still has made no difference. im hesitant on moding my car (brakes and suspension) if my engines going to need R&R some point soon.

[Mike The Canadian]

Not sure if you should worry or not...These engines make all sorts of racket...
Our Buick Century with a 3100 sounds like a diesel whether it's cold or warm...It's been like this for at least 4 years.

Mine is starting to be audible when warm too these days (Malibu).
Although I'll let the experts chime in!