It's getting mighty cold here in MA, and I'm just about due for an oil change on my 95 Bronco with a 302. I've pretty much stuck with 10W-30 non-synthetic for all seasons the last four years, but I've noticed a slight grinding noise (very brief) on cold mornings that worries me about poor lubrication on startup. Should I go to a different grade oil, and if so what grade? The truck has about 141,000 miles.

 

What oil filter do you use? A cheaper filter (Fram, most notably) will not actually trigger the oil bypass valve, causing your oil pump to fill the filter up with oil, instead of letting it get warmed up and circulated. Motorcraft uses a Ford-spec bypass valve, while Purolator (They ARE slightly different filter's then Motorcraft), Fram, and others use another design. Purolator's design is reliable though..Fram's just cheap.

What brand of oil do you use? If you went with a Havoline or Motorcraft oil you'd be ok. Motorcraft has joined the ranks of those "conventional" oil's which actually have some semi-synthetic base stock. Pennzoil also does this. Anyways..Chevron Supreme, Havoline, and Motorcraft are often recommended for people not wanting synthetic.

I personally run the Motorcraft 10W30, and my motor grew up on Havoline for quite a while.

I don't know how 302's take to 5W30, sorry. I don't know that the 5W30 would have much lower of a pour point then the 10W30. Other's here know the pour points and such.

 

The noise you're hearing is the oil pump bypass. It's perfectly normal. What this does, is it bypasses part of the oil pumped by the oil pump to prevent the filter from exploding from excessive oil pressure. This indicates that your oil is too thick for the conditions. I'd change it out to a 5w30 for winter. I would still run a 10w30 in spring, summer, and fall though. Take your pick of brand, they all work good any more. Dont spend the money on synthetic, from the UOA's I've seen on here it's a waste of money. Better results can be had in winter with conventional.

Fram oil filters suck. The anti-drainback valve on 'em doesn't work good, and they are otherwise poorly constructed. They use cardboard end caps on the filter media, and the housing is exceptionally thin. I'd avoid 'em. My personal favorite is the Napa Gold oil filter. Same as a Wix (made by Dana corp, has wix logo on box) but lower price.

 

What's the pour point difference between 5W and 10W, though? Tallpaul knows probably, at least.

 

I for sure agree on the filter allowing the oil to drain out. My buddy has the same problem.
Difference is he doesnt care......to the point of running 1,000's of miles past his oil change.

 

It's not so much the pour point as it is the viscosity. A 10w30 will still pour well enough at the temperatures he's looking at. The problem is that the viscosity, or resistance to flow, will be higher than the 5w30. This is what gets you, since the higher viscosity will cause higher oil pressure, and when that gets high enough the oil pump bypass kicks in and the total oil flow to the engine is reduced. So to keep the the oil pump bypass from making noise, you need to use a lower viscosity oil.

A good rule to follow is that if you hear the bypass buzzing on a cold morning, you need to use a thinner oil.

 

Off the top of my head, pour point maybe is a few degrees lower on a 5w30 than a 10w30. Really there is more variation in pour point among different brands for a given grade than variation between grade within a brand. But as Rusty70f100 says, the viscosity is the key and those are given in low temp cranking and low temp pumping. All the "w"s have to be at or below the same low temp viscosity (60,000 cP), but the 5w at -35C, the 10w at -30C, etc. Low temp cranking is often printed on oil spec sheets at the oil company web site (usu. listed as CCS). Max low temp cranking viscosity is 6600 cP at -30C for the 5w and 7000 at -25C for the 10w. Unfortunately I know of no way to compare between the "W" grades on these since the temps differ. But you can see that the 5w has to be thinner at a colder temp than the 10w so it should flow a lot better. We need to know what brand Swensen is running. Then we could find the stats and see what is better for cold temp. (BTW, I run an oil pan heater for the cold morning starts.)

Here is the API chart with the maximums (and minimums for higher temps):
http://www.infineum.com/information/viscosity.html

How cold is it up there in Maine? I can't imagine it is dipping quite down to zero F yet (man it's going to a balmy low of 40 tonight around Detroit) and 10w30 should work ok above zero.

 

I think a good idea (and if you are married, probably don't tell your spouse about this) Put a 1/2 quart of any brand name 10w30; a half quart (all seperate containers) of 5W30 dino, a 1/2 quart of 10w40 and a 1/2 quart of straight 30 weight HD oil. A 1/2 quart of 5w30 synthetic oil. Let them sit overnight in the freezer on a Friday night. At Saturday, 12 noon, take them out and observe how they pour. About 2 years ago, I did just that, as a written science report for my son Ross who was in 7th grade at the time. I also had one more 1/2 quart of 0w30 Mobil 1 that was used in the experiment. (the 5w30 was Mobil 1 as well, blue cap). What my son and I observed is why I have chosen, and use Mobil 1 0W30 year around, in my Aerostar van, with all-around excellent results. Just a suggestion is all. Ed PS The oil used in the experiment can be recycled. I simply poured the entire concoction into three 1 quart containers. I use this oil in my hand held oil squirter for various tasks around the house and family fleet (lubricating door and hood hinges, etc. you get the idea. ).

 

PS TallPaul's suggestion using a block heater is probably the best idea. When I lived in northeast Ohio during the 70s and early 80s, I would pull my winter beater ride (with hard, snow and ice chunk *****, caked and frozen onto the wheelwells and fender-lips) as close to a flat wall, or garage door, to limit frigid airflow around the radiator. Then a would shine a spotlight directly on the oil pan. Cheap, but effective, when leaving for work the next morning at -10 below. (And here in NoCal, people complain when it gets near 30 degrees. When you've been living around zero degree temps for a month, 30-35 degrees seems like springtime. 35 degrees, and I would be washing my car, to remove road salt, and flush the undercarriage off!)

 

The spotlight trick was in Popular Mechanics some 30 or 40 years ago. I think you can get some pretty intense flood lamps or even a heat lamp. I like the heating pad as it glues to the pan and so I don't have to stoop to push a lamp under and I think it warms it better. I still get a period of pretty cold afternoon starts, but I figure I get rid of about 2/3 of the really cold starts this way and that has to be good.

The synthetic is a great way to deal with it too. Just thought he might be leary to try synthetic at 150000 miles. I did put Synpower in the Aerostar at 105,000 and no leaks yet, but only 700 miles.

 

Wish I could give you a brand, but I generally buy the cheapo stuff (whatever brand that may be at each store) since I'm pretty religious about changing it out at or before 3,000 miles or three months, and since there's been a couple years I put maybe 5,000 miles on in a year, that works out to an oil change roughly every 1250 miles. I bought the Bronco in Oct. 2000 with 114,000 miles, and now it's Dec. 2004 and all she has is 141,000 miles. That's what living at college and walking to work will do for ya. I'll probably put 5w30 in this next oil change, then switch back for the spring. Thanks guys.

 

That sounds like a good idea. I have always run 5w-30 in the winter months, and 10w-30 in the spring/summer/fall months. 295,000 on the oldsmobile and still starts in the winter!

P.S. I live in North Dakota where it has gotten -36F

 

Wife's Aerostar did 2400 miles in the last 6 month OCI. I decided to go synthetic and shoot for one year OCI. I believe you could do exactly that. Put the synth in in the fall since the cold properties probably are best with the new oil. You could run Mobil 1 5w30 and probably not pay any more than you are paying now for oil and use only one filter the whole year. Save a lot of time crawling under the truck and get better cold start performance. Still grease it spring and fall though.

 

TallPaul, I believe it when you say that spotlight on the oil pan idea has been around for a long time. I learned that from my Dad when I was 14-15, and watched what he did. He also taught me about always keeping the gas tank on full during zero degree days and nights, and using dry gas, on occasion. Your idea about using a heating pad, is also an excellent one as well! How about this? If I was living in the snowbelt, I would insulate everything I could. Especially during zero, frigid temps, as when it warms up, you could remove the insulation if needed. I have heard that wrapping your exhaust manifolds and pipes is good, becuase it keeps heat inside the pipe and head much longer (cool down takes longer) Use the wrap that is used on headers. Thermo-Tec is a quality manufacturer of this kind of product. You can also wrap and insulate the oil filter. This keeps the oil much warmer. Then I think, the key is insulating your radiator and heater hoses. Even if you insulate only 75% of the hoses, that is all you need, for hot, toasty warm heat during frigid temps, especially on cars or trucks used for short trips.

 

For very cold environments the insulation would be great for say a trip to the grocery store where you can't plug in.

What about an oil pan with a built in heater that runs off propane? No such animal, but the idea popped into my head because of the water heater in the motorhome. It would be perfect, with an igniter switch on the dash. Just park, open the valve on the bottle in the bed of the truck and hit the igniter. The indicator lamp would light on the dash and a thermostat would control to keep your oil around say 120 F. This might actually be a practicable setup for all the folks in very cold regions.