I just got this 1992 F-150 XLT as my first car. It is loud from a cold start up but only in park. As soon as I switch from park to any other gear it quiets down to a sexy purr lol. The loud noise is accompanied by a slight but noticeable rumble in the cabin. This is really annoying because like I said before when it's not making the noise, the ride and idle is super smooth. I just worry that it my be a faulty or dirty fuel injector. SO what do you think?

 

well my truck kinda does that too. when i start it it idles really high then it settles down after a few seconds

 

Might also be the type of muffler.

 

No mine stays up there, and if I shift out of park it goes away and If I shift back without driving any it will still make the noise.

 

try leaving it running for a few min to see if it eventually idle down... most engines run at a high idle when first started to warm the engine up... a warm engine runs better and get better mpg than a cold one

 

yes i agree, mine takes several seconds and possibly minutesto idle down. when i start it, the engine idles above 1K rpm for a while, then after a bit it idles down and runs just right

 

Yeah I let it idle for a while before driving, it ever idled down but I could see what it was going for. I think my truck may just be like that until it gets warm. Thanks for your help!