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MG MGB Technical - Oil change question

I know it is a good idea to change the engine oil prior to putting my MG's away for the winter, but is there any reason to then change it again after winter storage? Car is kept in a car cocoon (bubble) but is in a unheated garage.

Only issue I can think of would be moisture condensation.
Bruce Cunha

I usually change the oil once a year and the filter every other year, this is based on the 3K miles per year max that the B covers. I usually do this in Febuary/March when I am looking around the car prior to it's MoT. I use a semi synthetic in the hope that it will stick around on the wetted internals. So far so good the engine was last rebuilt in 1995.
Stan Best

Bruce: If you do not use the car AT ALL during the winter, why not leave the crankcase empty, then fill it in the spring?? As I do drive mine in the winter, ONLY when the roads are CLEAN & DRY, so it is stored with fresh oil & filter. I have it under wraps in my unheated garage as well, but it does get used - not much but run maybe once or twice a month.

cheers

Gary :>{D
79 mgb
gnhansen

I was thinking about that Gary. Can't see there is any advantage to having a pan full of oil if the car is not run. All the parts are above the oil level in the pan.

Others have thoughts on this?
Bruce Cunha

I change mine *after* the winter, not before. If we get dry, salt-free sunny Sundays (none last winter) the car gets an outing of 30 or 40 miles, if not it gets its engine run for about 20 mins once a month in the garage and its wheels turned 1/4 revolution. I'd rather change it after the winter to get rid of any effects of short running, even though it gets pretty hot at a fast-idle (throttle wedged, not choke pulled). It's all a bit marginal as to benefit anyway, the engine is sitting with old oil coating the bearings etc. just before a change, whenever it occurs. And to change it both autumn *and* spring would be really anal.
Paul Hunt 2

After reading other threads about "acids that develop in the oil" and their supposed effect on bearing surfaces I like to put fresh oil and filter in, run the car for a few minutes to get it circulated, then store for the winter. In the spring after a few hundred miles I change it again. I figure overkill, but cheap insurance.
Sam

I always change the oil and filter before I put the car away for the winter, to get out all the acids, water etc. that have accumulated in the oil and cover everything in fresh oil. I then start the engine about once a month during the winter, and run it reasonably hot.

I believe the acids, petrol and condensation formed during these winter starts are still a lot less when spring comes than what was accumulated before the oil change. Petrol and water gets out during the first long run anyway. So I dont see any reason to change the oil again in spring.

Tore
Tore

Most oils start out Basic to allow for build up of acid combustion by products, so if you leave it with 1/2 it's service life on the oil it will give minimal corrosion.
Stan Best

Bruce,

I would not leave the crankcase empty. Should anyone attempt to start (hey it could happen) you know the rest. I like Paul Hunt keep my cars ready to drive all winter so a change in the autumn is my routine.

A question for you, do you use a fuel stabilizer, and disconnect the battery/ies?

Regards,

Larry C. '74 B/GT
Latty C.

2 comments:

1/ The stability of oil and the chemical buffering is far superior to oil 20 years ago, let alone 40 years ago.

2/ The sulphur and other acids and byproducts of combustion with modern unleaded gasoline are far less than the amount of oil contaminants in the past.

The storage concerns voiced were valid in 1950 but not now.

Having said that, I would not park the car for a winter with a sump of oil that hadn't been changed in 7,000 miles, although it probably would still not be corrosive enough to damage anything.

Barry
Barry Parkinson

ZDDP is not just an anti-wear additive but is also an anti-corrosion additgive. With the lower sulphur fuels over the last few years, TBN values are reducing with low suulphur fuels being available.

http://www.wipo.int/pctdb/en/wo.jsp?KEY=02/18521.020510
The feature of the invention is that the use of a low sulphur fuel enables the amount of anti-wear agents containing phosphorus such as eg ZDDP to be halved without any adverse effect on the antiwear performance of the lubricating oil.
Paul Wiley

Exactly why I posted this question. I value the opinions and thoughts of this group and they give you a variety of things to think about.

My normal routine is change oil and filter, add stabilizer to the fuel, run the vehicle and put it into its cocoon. I put a "keep charge" unit on the battery, put the car up on jack stands just to the inner edge of the A arm (so there is some load but not as full as farther out on the A arm).

I have a fine screen on the intake fan of the cocoon so little critters do not get in the car.

I normally do not change the oil in spring, but my neighbor who also has a classic car was saying he does because of possible condensation in the engine due to our cold winters.

Bruce Cunha

Condensation is my major concern. I believe the rule of thumb is to change oil at least every six months even if mileage is nil. Having said that, although I love to work on these cars, routine maintenance is something I have to force from myself! I am not recommending this aspect of my mindset to anybody, but it has led - over many years - to the discovery that these cars can stand a helluva lot of benign neglect and they still keep right on truckin'.

I always do change oil and filter every spring when the car comes out, but regardless of good intentions, I'm inclined not to in the fall. Reason? I don't feel like it! That doesn't mean I won't change it late in the fall if it's clearly over 3,000 miles since the last change, but if it isn't...

So what happens the next spring? The oil pressure is the same as always. I change the oil/filter, run the car on lots of short trips (daily driving to work, when I used to work!), then plunge into some serious long ones - 1000-to-6000 miles. I should do better, I know. But these are very forgiving engines.

FWIW,
Allen
Allen Bachelder

When condensation is mentioned here it is the products of combustion as well as the acid every gallon of petrol produces more than 1 gallon of water. Even this is no problem if the vehicle is used enough as the water will be boiled out of the oil. When all we are looking at is the amount of airborne water vapour in a B series crankcase on a winters day in a cold part of the Union without combustion by products, it is non issue. Save your money and the environment leave the oil till it is due on mileage or time. Railway locomotives and big trucks do not even do this, they have a sample analysed and only change when test results show it is needed, clearly there is a cross over point where the cost of the oil because it is 100s of gallons justifies the cost of testing, but this is a clear indication that when we follow schedules we change when it just may be needed, not when the oil is not up to the job and prolly 9 times out of 10 tsts would show we could get more time and mles before we have to change.
Stan Best

Talking about winter storage, Crane Cams recommend the use of mineral oil in engines that are stored for longer periods:

As stated above, we do not recommend synthetic oil on
flat tappet camshafts because it is so slippery that the
lifters do not rotate as well as with mineral oil, and lack of
rotation is “death to the camshaft”. Additionally, if a vehicle
using synthetic oil is stored for a lengthy period of
time, the oil falls off the camshaft and the cam is “dry”
during the engine start up. We recommend only regular
mineral oil for vehicles that are only started occasionally
or stored for prolonged periods.

I copied this from an information about flat tappet cam break in procedure:

http://www.cranecams.com/pdf/548e.pdf

This supports information I have got from a friend of mine, that mineral oil is more "sticky" and gives better protection in an engine that is only used occasionally.

Opinions?

Tore





Tore

Larry C: point is well taken about someone starting the car without knowledge of the drained crankcase. The way around that is to tag the battery cable once disconnected as well as the ignition key and column.

The main question is still open. Why not drain the crankcase and leave it empty for the winter storage?

I don't see any harm in leaving the crankcase empty for the winter storage. This way, no acidic build up forms in the oil. Any condesation would be minimal anyhow. With fresh oil after "recommissioning" any condensation would be boiled off after the car has a good run.

Any thoughts??

cheers
Gary :>{D
79 mgb
gnhansen

Rust prevention is covered ti this study about half way down

http://10.45.0.106/778949508/650540544T061110130609.txt.binXMysM0dapplication/pdfXsysM0dhttp://www.smartsynthetics.com/pdf/study_of_motorcycle_oils.pdf

Tore

"sticky" is an interesting question, if you consider same viscosity synth/mineral and ignore additives then the basic cheap group 1 oils will be more "sticky" than other base oils except esters which are used in synthetic oils, and the most "sticky" oil would probably be Castor oil which is a type of ester.

Stan

Without testing there would be some degredation of the additive pack if the oil has been used, and the additive pack is used more quickly protecting a mineral oil. Whether this effects the performance of the anti rust prevention capabilities of the oil to a significant degree is open to question.
Paul

I believe the thing about changing the oil at time intervals, if you haven't reached the mileage interval, is because the manufacturer assumes that if you are doing low mileage you may well be doing low mileage *per day* and hence *never* running the engine long enough to boil out condensation. If you run the engine infrequently, but for at least 20 miles or the equivalent when you *do* run it, then you can safely ignore the time interval ... unless you store the car under water.

Like Larry I think storing the car with the sump empty if a very bad idea. It saves nothing, anything captured in the oil in the sump isn't doing any harm to the engine anyway. And even if it were capable of doing so, it is in the same condition as the oil surrounding the bearings, which will be the same regardless of whether the sump is empty or not.

Remember Murphy's Law - if it can go wrong, it will. I.e. somewhere sometime someone is bound to start an engine that has no oil in the sump ...
Paul Hunt 2

Summary:

Condensation is not a storage issue but a short stop running issue. The engine produces blowby moisture from combustion (witness the vapor out the exhaust on a cold morning). If a cold engine is the same temp as the garage in which it is stored there is no reason for any meaningful amount of condensation during storage unless you start the engine.

The oil film will degradate during storage. Probably will unless you start the car every week or so. If you start the car then you need to get it and the oil hot enough to bake out the moisture produced by running the engine. Every time you start the car - particularly after a week or so- there will be minimal lubrication for a short period. If you start it a lot during the winter you may need to change your oil part way through?

It's easier just to use your car all the time, or park it and forget it.

Barry
Barry Parkinson

May be of interest

http://lib.store.yahoo.net/lib/eofcorp-store/rust.pdf

http://www.sacskyranch.com/corrosion.htm
Paul Wiley

I find that the engine - on the temp gauge at least - gets *hotter* running at a fast idle in the garage compared to on the road in winter (even summer) as it doesn't have the additional surface cooling of the sump, block etc. from forward motion through cold air. This is why people blank off their radiators in winter, it isn't so much to stop the radiator overcooling (the thermostat is probably closed anyway) but it greatly reduces this surface cooling and allows proper warm-up and heater function. It's also why winter stats were hotter than summer stats, to compensate to some degree for the surface cooling.

I realise that the internal temperatures of the combustion chamber won't get as hot as on a good thrash, but believe me the coolant and oil gets plenty hot enough.

So we now have change the oil before, during, and at the end of winter? :o)
Paul Hunt 2

This thread was discussed between 09/11/2006 and 11/11/2006

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