engine knock

i have a 91 islander with a 6cyl,,it recently started knocking while accelerating,,i dont hear the knock while at idle or when i stay at a constant speed.only hear it when under a load..should i do a compression test?acceleration hasnt dropped.and doesnt seem to burnin excessive oil...

check your header bolts. mine started knocking cause i lost a bold in the header. also, obviously check your oil level.

Keep a close eye on your oil pressure! If you don't have a guage install one. If it sounds like a bottom-end "hard knocking" you could have a bearing failure, or it could be "piston_slap".