otter5555

just bought 2005 4.6 auto

ac is cold
if you let it idle in gear with ac on after about 5 seconds it starts to hammer and engine seems to misfire. really loud hammering noise

if you put it in neutral or park, ac blows cold and makes zero noise

any ideas?

Dino Dino Bambino

Do you get the same noise if the engine's idling in Drive with the AC off?
Just trying to figure out if the problem is the AC compressor or the torque converter.

otter5555

only in gear with ac on. in park or neutral no noise with ac on
i let it idle in gear, ac on for 30 minutes yesterday.....no noise at all

just does it when it wants to

Dino Dino Bambino

So if there's no noise when the engine's idling in gear with the AC off, that would suggest there's a problem with the AC compressor.