Toyota Repair: sticking cam chain aduster, oil consumption, klms

Question
Hello Have a Toyota 1989 RN85R ute.Has a 22r mt and is an automatic.Has an irregular timing chain rattle.Sometimes no rattle for 3-4 days then it can be very loud.Rocker cover off chain guides okay.Is a gem recon mt with 40000 klms. I bought ute when it had about 20000 klms on mt.Has allways used oil,about a quarter of an inch on dipstick every 100klms.No real buildup on plugs no visible leaks.Mt has low power on hill climbs.Compression on cylinders around 150lb.Could the chain rattle be caused by a sticking oil activated chain tensioner and be cured by an engine oil flush.At 63 yrs I do not wish to attempt to do a timing kit replacement.Could a chain replacement cure this as its about the most I can afford.Any advice appreciated. This problem occurred after a friend used excessive gasket sealant on inlet maifold gasket replacement.Thank you

Answer
Yes the rattle could be caused by a chain tensioner or loss of oil pressure, it's difficult to say which, if you are not using a multigrade oil try switching to a 10w-40 oil, have the oil pressure tested, maybe the oil flushing will help or it could make it worse. The oil consumption is excessive and could also be the cause when the level gets low.