<br><br>Good tip on bringing a thermometer. I would be upfront, as polite as possible, and tell them over the phone that I will be bringing one to check the temperature, so they shouldn't start it at all. That way they won't try to cheat, which ends up costing me a trip there, wasting time & gas....and not buying since I'll be all suspicious now that they've lied. <br><br>Another thing though, GM seems to have problems with piston slap on some motors. I know my 98 LS1 motor has it on cold startups on mornings that are under 50 deg F ever since 60k or so (118k now). I always use synthetic oil and let it warm up first, but this seems common for this motor, according to LS1 websites. <br>4x4tour said: <br><div><div>Like i tell anyone who'll listen about checking out engines. make sure its COLD (overnight cold) and then listen for cold start bearing noise and/or piston slap. I always use a cheap laser thermometer to determine if the owner starts it up before I get there (after I advise that i want it "not started"). It only take10 seconds or so to hide the initial cold bearing noise / piston slap, so the thermometer tells me if the seller is a liar as well (point it at the exhaust)... </div></div>