Engine clatter

hi everyone im posting a video link to my prius. it was warmer the day than it usually was so it dosnt make the noise as bad however there is usually a lot of clatter/knock from the engine when cold. does it at idle and while accelerating. it gets less once the engine warms up but has been doing it for a while. car has 93k miles and synthetic oil is used. there is also a metal rattle sound almost like a heat shield that is loose. idk if that is part of the engine issue or not. but it only happens in winter or when temps fall below 60 degrees. kinda hard to hear on the vid but its there. any help would be appreciated.

 

this is a cold start. it sat over night with -1 degree temp. i have to use 5w-30. tried 5w-20 and it seemed to blow by and use oil. since going back to 30 weight it hasnt used a drop so far.

 

yeah i only tried 5w-20 in castrol. but ive since changed from castrol to mobile due to castrol in these winter months caused like a foam to appear under the oil cap. thought my head gasket blew but according to toyota it was oil additives. engine oil was fine although there was a slight milkyness on the dip stick about halfway up the stick but nothing in the oil. and it seems to sound fine after its warm. winter here tho is brutal -25 to -60 below zero temps all winter long so the car never really fully warms up. you get heat from the heater but the engine is always running cool in my opinion. summer months you just hear a slight tick of the fuel injectors and valves, but winter it pretty much sounds like that all the time.

 

yeah winters here are brutal on a car. and almost every car ive had has always had a little bit of yellow foam under the cap during winter months. the dealer said its normal since the cars have a hard time reaching operating temp they cant burn off the accumulated vapor inside the engine unless you drive 200 miles or so. im gonna keep a eye on it during the summer months. coolant is still full and no contamination there. inverter fluid is kind of thick but its almost due to be changed anyway. but as long as the engine sounds ok i wont worry to much.

 

once i figure out how to properly bleed and do the coolant im going to do it. im not paying toyota dealership here 200 bucks to have less than a gallon of coolant changed out. i hear its simple to do but i have to wait till summer to do it

 

no i dont have the grill blocked at all. my gas mileage really sucks too. avg all winter is 23 to 24.9. but all summer i was getting 65-70 with the ac running. lol i hate this cold climate but im stuck here. really sucks

 

its -5 here right now but with windchill its -20. low tonight is supposed to be -36. i was afraid to block the grill because people say it could seriously overheat the engine. so ive always been to scared to do that. i cant afford major repairs until my car is paid off since i live on a disability income. but i tell ya. the gas mileage in winter months really sucks but still better than my previous car.

 

yeah it sucks. toyota should have put heated steering wheels and seats in all of the prius's regardless. mine at some point had a heated seat installed but for some reason i do not think it works. cant locate the fuse for it either, and there are no lights that come on saying if its working or not. gonna be hard to track down lol

 

RIGHT? its like holding a handful of ice cubes in your hands. when it gets really bad out for short trips i have to peel my fingers off the steering wheel because they are so cold they dont really work LOL. i noticed that a white 25amp fuse under driverside foot well is weird. has a piece of metal sticking out of it but the fuse isnt blown. idk if its there to hold that fuse in or not. i was going to replace it but idk what that fuse goes too and cant find any diagram that says what it is either. the 5amp fuse which i think is for the heated seat looked ok so idk if the heated seat just quit or if a wire came loose somewhere. :/