Problem When Cold Starting

[DOn_MEGA]

I live up in Canada where the temperature can reach -35 degrees celsius on some days. I have a 95 318is M42 motor. On the first start of the day, when my car has been sitting outside all night in the cold, the car starts but i get three bangs coming from the engine and then it's fine all day. It sounds like someone is knocking on the underside of my hood just in front of the driver. If anyone might have an idea as to what this may be, could you please let me know because it is very frustrating.

[TMac325is]

from what i am reading, this is what i think

when its THAT cold out, the oil in the engine is extremely thick and its very slow moving, once you start that engine and pistons start firing and wheels start cranking, there is not enough time for the oil to move in so there is metal to metal contact taking place causing the sounds that you are hearing

just a little bit may not kill your engine but damage may still be done

im not sure what type of oil you are using, but wow those temperatures are ridiculous and im suprised your car starts at all

[uiuc240]

you MUST get an engine block heater. i'm surprised you don't already have one.

[DOn_MEGA]

I use 5W30 semi-synthetic motor oil............ and i recently had a block heater installed , it's plugged in most of the time.

[uiuc240]

perhaps install an oil pressure gauge and monitor what's going on? if this is truly rod knock (bad thing) then you are going to have more trouble as the time goes by. but if this is something like a busted motor mount then it could be an easy fix. do you have any other descriptions of the sound?

Eric

[DOn_MEGA]

The past few days, the temp. has been a little warmer (-10 degrees celsius) and i have had no trouble starting the car and no banging noise. It only seems to happen when the temp. reaches -20 degrees celsius and lower. Just two or three bangs or knocks on the first start of the day, then the car starts fine the rest of the day.

[97alpineM3]

Good question to ask.. and for your to find out or see if you can remember... what vicosity of oil are you using.. you might want to see if you can fun a little higher...

Good Luck,

Les

[DOn_MEGA]

Thanks for the feedback guys but i think i have found my problem. I had the car lifted up on a hoist the other day, and i used a pry bar to see if i could move the engine. As i thought, there was a lot of play on the drivers side of the engine. I pryed the engine up and found that my motor mount was broken. Any ideas where to get aftermarket motor mounts??