odd motor noises

[--weezl--]

so i've been noticing for quite a while that upon startup especially when cold, my truck has been making 2 very distinct noises, the first is when the engine is cold, over night or sitting 8 hours while i'm at work, and it's upon start up for about 2-4 seconds, it has this chirping, kind of sounds like a cricket, but not quite so high pitched, if i shut the motor off right after it starts, it will chirp till the motor stops spinning, and will do it again if i re-start, i could potentially make this noise by starting and turning off the motor repeatedly, for quite some period of time. it does NOT do this when the motor is warm

the second noise is a hydraulic sounding hum or buzz out of the motor, it sounds a LOT like a forklift's hydraulic system, or a tow truck's, that whine that you hear. This whine is ONLY present upon initial startup in very cold tempatures... the days where i HAVE to start my truck up before leaving, i start it, and it starts this whine, and continues it till i am back inside the house... when i come back out to drive off, it is gone though... recently the tempature has been down to -30 in the morning on some days and over the last week we have had highs of -15, and it's only happened a few times...

we usually have a month or so of -40ish weather, sometimes hitting even colder than that, coldest i have seen was -50sometihng i think it was... frost bite sets in to bare skin in minutes

fwiw, my coolant was tested yesterday, and was rated at -40

 

[rusty70f100]

The second noise is the oil pump bypass. What is happening is that the oil you're running has turned to syrup-like goo. The oil pump has a pressure relief spring and valve in it that limits maximum pressure so that on cold mornings it doesn't blow the filter off or do other bad things. As the oil pump goes around and the valve does it's thing, it makes this noise. What it means is that you need thinner oil, or some kind of heater, such as a engine block heater, warm garage, etc.

I don't know about the first one.

 

[--weezl--]

ok, the whining, isn't necessarily a bad noise, it's normal because it's flat out too cold? i assume with this noise going on, it means that my motor is more or less running dry till the oil thins out enough?

i THINK the first one might be the fan clutch, but that's merely speculation... i've heard a similar sound when you get air bubbles into the water pump (not enough for it to cavitate, just enough to splash a little)

maybe i'll start using my block warmer this winter... lol, probably take care of my nearly no crank problem at -33 like it was last week (also has a factory electric battery blanket)

 

[pcollins]

what viscosity oil are you running?

 

[--weezl--]

no idea to be honest with you... i am going to assume 5-30, the oil has been changed at the dealership since i bought it, and it was changed again yesterday...

 

[pcollins]

I'd make sure its 5w-30. I know some dealers/places like to put 10w-30 synthetic in everything. and thats wrong. A dealer should be good about putting the rite oil in. but maybe call and check to make sure?

 

[--weezl--]

i'm going in monday to get my transmission and diff looked at, i'll double check then... i doubt it's synthetic, it was only 29$ plus tax... (i got it for free because it took too long though)