1997 850 NA - starting issues at 1deg F

[cn90]

I used to live in Montreal Canada in 1980s...
Temp sometimes down to -35C with wind chill.
I had a block heater in my then 1991 Volvo 240 4-banger engine.
I plugged the block heater overnight, next morning I measured the coolant temp just for fun, it was -10C.
So, my little experiment showed me the block heater provided about a 25C gain in coolant temp, it is a little help to get engine warmed up a bit quicker.

Re oil: best bet is synthetic 5W30 in the winter. It flows better than standard 5W30 oil.

xHeart, as a test get a bottle of each: standard 5W30 vs synthetic 5W30, put them in freezer overnight. Next day shake them (or pour them into the engine) and see which one flows better!

[erikv11]

We talked about this in several posts last year - the temp that matters is in the engine block, not in the peripherally mounted coolant reservoir or radiator etc. The key feature of the block heater is that it heats that huge slab of metal called the engine! Like the oil, the coolant will instantly come up to block temperature once it starts to circulate. With the 500W heater the engine block is warm to the touch on a 15 degree day. I posted numbers last year showing a 60 degree difference. I don't know what kind of heater you were using but a decently sized one makes a huge difference. All discussed in https://www.matthewsvolvosite.com/forums ... =1&t=67151.

Wind chill is irrelevant to a vehicle, it is a perceived temperature on exposed skin. What matters is the temperature.

I agree on synthetic, FWIW I am using Rotella T6 5W-40.

[misha]

...The battery voltage reads 12.38.
Misha suggested in another post to switch to synthetic 5w40. Which I will, but for now it is on Pennzoil conventional 5w30...

Here is a battery state of charge table temparature dependant:

E38_Battery_SOC_Table.jpg (156.85 KiB) Viewed 667 times

5w-30 or 5w-40 fully synth will not make any difference for cold starts since they are the same(5w).The difference is when engine is at operating temparature(xx-30 or 40 thing).That said....xx-30 is thinner than x-40 when car is at operating temperature and is not recommended to use when outside temperatures are higher than 30 degrees Celsius.

At 12.38v and with -17 degrees Celsius,your battery would be between 60-70% of charge,which is good for temperature that low.
Usually fully charged battery can loose more than 50% of capacity in extreme cold weather.

So....i wouldn't change anything and everything is in good working order.Just normal cold weather behaviour.

[cn90]

I have lived in Chicago before, temp nowhere near the Montreal weather.
I have never had the need for block heater in the US, simply b/c I only lived in Chicago and Omaha and temp rarely rarely gets below -20C.
In my experience, if temp > -20C, I don't need block heater simply b/c I use synthetic oil.
I hated running the extension cord to the car, plug it in at night, then unplug in the morning etc.

Block heater makes sense in further north environment such as N. Dakota or Calgary.

[BEJinFbk]

The rule of thumb in Fairbanks is plug in below 20F.
That said, my car starts at -10 without any real fuss,
But only if I haven't got electrify handy.

From the OP's first post, I'd be thinking about voltage.
Battery, cables and connections would be my first look.
Get a meter out and run some voltage drop checks.

You may also have a dodgy fuel pump relay, as suggested,
but if your voltage is low, you can see a similar problem.