Oil change after winter storage

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Staff member
May 27, 2002
Guelph, Ontario
On my car club's own message board, the topic of winter storage and oil changes came up, and I just wanted to confirm that I answered the question correctly. Someone asked if there is a need for a second oil change after the winter storage is done, if it already had a fresh oil change right before storage and the car was not driven or started? My answer to this question has always been that there is no need for that oil change in the spring, since the oil in there is going to be just as good as if it was still in the bottle, other than a bit of moisture which will burn off on the first drive. I'm 99% sure that I'm correct on this one, but just wanted some back up to make sure I've been giving the right advice all these years! [Smile]
Hi Patman, I would agree. As long as its fresh oil, there would be little to deteriorate it composition. Wouldn't want to leave old oil in over the winter! Some have recommended an oil with a high TBN to counteract any leftover acids, but I wouldn't think thats important. Others have recommended cranking the engine w/o ignition for a short time when taking it out of storage, to build up oil pressure. Hapuna
I'm also curious. What would happen if someone were to have old oil in their engine for the winter storage? Would the acids attack the metal? Or would they still be neutralized as long as that oil still had a strong TBN?
Patman, My initial thought is that since the oil is no longer circulating, the TBN agents would be localized. Corrosion could thus develop in certain areas where moisture and acids are present and "use up" whatever TBN was "locally" present. With the lack of circulation, it could spread like cancer. In the old days, recommendation was to start the engine once a month or so. Problem was it was difficult to burn off the condensation, making matters worse. Now, as long as you keep the battery charged, your're better off not starting during the whole storage period. Only other problem is with A/C, as knowledable ones say you should run it occasionally to keep the seals moist with lubricant. Hapuna
I store my cars in winter, but I like to run them for a few minutes every week or two. When you get those nice sunny dry winter days I take it around the block a few times and I also run the air conditioner like was mentioned.
I agree with Hapuna Beach. I don't know how effective even a high-TBN oil would be if left in the exact same position for months at a time. I'd suspect that you might get light pitting/etching on the crank and maybe stell cylinder liners ... which would not be too bad if it only happened once or twice but it would likely happen many times if the owner is a creature of habit and left old oil in there every off-season. Years later, the engine smokes/knocks despite "regular" maintenance ... I wonder why? [Confused] [Duh!] --- Bror Jace
I always tell my friends that store their cars that it's not a good idea to start up the engine at all during winter storage, unless they are going to drive the car a good distance. Starting the engine, idling it, and then shutting it off, won't get the oil hot enough to burn off moisture. I tried this once with my mom's car, in order to warm up the engine to change the oil (it was snowing outside and I didn't want to drive her car first otherwise I'd have gotten totally wet under the car) So I idled her car for 20min, and then started draining the oil and it was barely warm. Her car's oil is usually so blazing hot that I can really burn myself if I don't watch it. This oil had almost no heat in it. So when you idle an engine without putting it under load, and then shut it down, you're simply introducing even more moisture in there. This certainly isn't good for a winter stored vehicle. When I had my 98 Formula, one of the winters that I stored it I did not start the engine at all for 4 solid months. It started right up in the spring without any strange noises and drove perfectly. I can't possibly see any damage occuring to an engine if you don't start it for that long. I think if I was storing it for 6 months or more then I might worry. I also think that an oil with moly would definitely help in a case like this, since that moly would provide the extra layer of protection on that first cold start.
Patman, the damage from storing with oil oil shoes up on the bearings. Take apart an engine that has been stored for a few months with old oil and the bearings will have black spots from acid attack. On about 20 engines I've never missed telling the owner what his practice was by looking at the bearings. Here they aren't stored for the "winter", but between harvests. Harvesters are normally put to bed in December to be used again in April, and put up again in May until October.
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