ltoolio

Hey all,
As fall & winter comes to Chicago, I'm looking ahead to doing some fluid work on the car - coolant, engine oil, tranny oil, brake fluid flush.

I seem to recall prior guidance given on when (at least some of) these should be done - e.g. right after the last drive of the season and the car goes up on lift bars whereas some should be done at the start of the next season.

Assuming I'm not making this recollection up, any guidance on when each should be done?

Thanks, as always!

Wisconsin Joe

I prefer to do the oil right away. The reasoning is that the old oil has various contaminants in it, and "fresh" oil is better if it's just going to be sitting in it all winter.

Also, I tend to pull the drain plug and then let it sit and drip for a while. Like a week. Or even 2. Some are of the opinion that it should be done right away when the engine is still hot, and there is some validity to that. But I've pulled the pan after doing it cold and letting it drip and found that there wasn't much that didn't drain. Even cold oil will all drain out if you let it drip long enough.

Coolant can be left "for your convenience". Anything that's in it has been there a while, and either won't hurt or has already done it's damage. Same with brake fluid.

Trans is the same, at your convenience, but with the idea of do it early enough that you can let it drip a while (for a manual trans, autos are a bit different).

None of those gets changed often enough for the scheduling over winter to matter much (yes, I know perfectly well that those are somewhat conflicting)

Others may have different opinions, that's fine.

hacker-pschorr

I've been changing the oil in spring for 25+ years. If it's damaging something I'm not aware of it.

Frankly I don't get it. Most cars which fall into the discussion have 2-3k miles (at most) on the oil in the sump. It's far from "needing" to be changed if the car were to be used another 2-4 months. Sitting in the bottom of the pan isn't hurting anything.

Oil like everything else oxidizes, so why "age" the oil 4-6 months by "storing" it in the bottom of the oil pan?

Frankly 4-6 months isn't really storage either, that's not very long even for the fuel in the car (I've never used Stabil either). The only reason why this topic ever comes up is the annual oil change intervals regardless of miles we all have been convinced to follow.

ltoolio

Thanks, Joe & Hacker..appreciate the input from my neighbors to the north.

I was leaning towards doing everything right after the last drive for the reason of the fluids being heated up and flowing easier.

Given you have some divergent opinions, what about a best of both worlds - pull the plugs, let them drain for as long as there's drips coming out, put the plugs back in when they are dry then refill at the beginning of the season. Is there any risk of negative reaction in doing so?

All this said, it's probably at a level of minutiae that isn't going to affect things much one-way-or-another. The little drips of oil I might get out at the end aren't going to make up for past sins of maintenance (should they exist), but I figure if I'm going to do it, and I have the time, I'm going to do it the best I can.

dr bob

My thinking on coolant and brake fluid changes is that they get done on their schedule regardless of the timing relationship with storage. Brake fluid gathers water over time. Coolant goes acidic over time. You can use test strips to determine the needs, or just follow a schedule that you know will be safe.

Oil gets changed as the last duty before the car goes into storage. Unless you can make sure the last drive is long and warm enough to boil off any moisture that's accumulated, having fresh dry oil in the sump is a plus especially if your driving patterns have included some recent (in miles) short runs that didn't get the oil up to temperature. A change with fresh Mobil-1 on sale in the 5qt jugs at wally world, plus a filter from our vendors, works out to well under $50 if I do it myself. I could try to second-guess this philosophy if I knew for sure that the oil in the sump is moisture free. Or just call it insurance for peace of mind. I'm well into my second tank of fuel for the year, so have maybe 1k added to the odometer this year so far. So nowhere close to due for oil due to mileage. If the stars align on projects and the Great State of Oregon manages to avoid putting de-icer (mag chloride slurry) on the roads for another month, I'll add the miles to/from Sharktoberfest for this year. Still nowhere close to needing a change just on miles. It gets changed anyway.

My thinking on using Sta-Bil is that my car sits for almost it's whole life, waiting with fuel in the tank to be exercised a little. Most pump unleaded fuel these days has ethanol in it unless you spring the $$ for non-ethanol premium. Ethanol additives have a tiny bit of water included, plus they glom onto any condensation in the tank. Without regard to stored fuel "going bad", I'm getting in the habit of adding Sta-Bil to every (read: all three...) tank-load of fuel that might live in there for a long enough for the water to drop out. Again, it's cheap insurance. Water and associated corrosion crud are truly the enemies of fuel pumps, tank inserts, inlet filters, and also injectors, regulators and dampers. Why risk that damage when the insurance is so cheap?

I store the 928 with a full tank of fuel, mostly so the level sender and other metal bits high in the system will be isolated from oxygen. With good fuel and a dose of stabilizer, the risk of corrosion and any varnish/plate-out from evaporation is virtually eliminated.

Seriously long-term (years) stored toys get a different protocol, with a dry tank fogged with a marine protectant, and all the plumbing and normally wet bits full of ATF or Marvel Mystery Oil. Plus a lot more "preservation" stuff goes on with them for mechanical internals..

----

There are tons of expert opinions on all this stuff. I don't claim that mine falls into that category. It's a method that I've thought through over the course of several decades of various cars and toys, and it's worked so far. Is it overthought/overkill? Maybe. But it's cheap insurance for me anyway.

the flyin' scotsman

if you change in the late fall do you change again in early spring?

I plan on changing in the fall as our winter storage is ~6mths of ice and snow and use dino oil.

In the spring change back to full synthetic for the driving season............very cheap insurance

dr bob

Malcolm --

I put the normal synthetic dose in there in the fall just before rolling the car over to its winter storage position. Since the car isn't started again until spring driving season, I see no need to swap out storage oil, since it's typically done nothing but keep the inlet strainer wet.

Having oil in there offers the option of moving the car by its own power in an emergency, vs leaving the sump empty as OP Ryan proposes for his own car. Also eliminates the opportunity to accidentally start the engine in the spring with no oil in the sump.

the flyin' scotsman

I max the driving possibilities by keeping the car ready to roll until weather dictates it will not be moved; in our part of the world means months.

I also run both 928s on hi perf. all season tyres (Michelin A/S 3s) again to max driving season..........928s love cool air.

Then I pull the battery and store in house on a smart charger, cover her up and say goodnight until March/April.

hacker-pschorr

Yea...I think we (as in the community as a whole) way overthink this. A car sitting 3-4 months, the conditions around the car are far more important than oil that is maybe 8 months old versus 3....

Air up the tires, keep the mice out, keep moisture under control (thick plastic under-lament is easy insurance from ground moisture) etc...

As for fuel, most 91 around here is ethanol free so that's easy, but Turbo Todd stores his car every winter with e85 in the tank...... I'm not sure what the negative effects of storing with 10% ethanol fuel is, but his car doesn't seem bothered by 85% ethanol. But again, it's only about 3 months for his car..... that really isn't a long time.


This is why I would never store a car with an empty sump. The slim chance someone tries to start the car.....

Wisconsin Joe

Of course we are overthinking it.

And even the recommended oil change interval is pretty short.

I've had a couple years where I didn't put many miles on the 944 or the motorcycle and didn't bother to change the oil over winter.

I can't see it as a big deal.

And I don't know about up by you, but around here (Fox Valley) the only "Pure" gas is Shell & Kwik Trip. Maybe a couple others. The rest offer either 91 E10 or 93 E10. I'm running Shell mostly of late, mainly because they offer the "Gold Club" discount ($0.10 off posted price on Tuesdays).

I've stored motorcycles and the 944 every winter with E10 in them for decades. I stored the 928 with 93 E10 for the first few years until the local station that offered the cheapest premium closed.

No ill effects that I've been able to detect.

The only real risk in that is that you might forget that there's no oil and fire it up.

Keep in mind that there will still be a film of oil (and drops that just won't drip off) on the internals of the engine. And that there is a lot of "motor" that isn't submerged in oil, even when the pan is full.

hacker-pschorr

The three stations closest to my house (one Shell, two BP's) are 91 ethanol free. However, my gas station of choice is Costco with 93 e10. The only time I'm super paranoid is the gas can for my carbureted small engines. I stick to the ethanol free stuff there.

Why Costco? I'm there a lot, it's cheaper, and I've been reading more and more on the benefits of "Top Tier" gasoline which they have.

ltoolio

If I were to keep it empty for the season, which I'm no longer considering doing, I'd put put a note on the end of the negative battery cable reminding me that it's empty.


Both valid points. However, I'm sure that the last drop that would trickle out of the pan would be the one that has the contaminant that would have destroyed my engine



I didn't realize this was something more than marketing. More details here:
http://www.toptiergas.com/licensedbrands/