In Spring when I get my 85 300D out of storage, I first reconnect the battery that was fully charged in December. Then I try to start, but the battery seems to be very weak. It will hardly turn engine over more than one or two turns, yet voltage is good and it passes load test. I then put it on charge overnight. Try again in morning, still barely turns over. I think - Hmm, I probably need a new battery. This has happened for the past two years.

Luckily, my engine is in good shape and it will fire even when barely turning over. So I get it going and go for a run. I am afraid to stop just in case it won't start again! But eventually I do stop and next time the engine spins over fine and months later everything is still good.

Not sure what it is. Either engine gets tight during 3 months of storage or it is the starter motor that sticks and needs to spin. Anyone else have similar symptoms?

__________________
Graham
85 300D,72 350SL, 98 E320, Outback 2.5

It isn't entirely uncommon for an engine to get "tight" when sitting for long periods. If you know you're going to be parking it, try putting a thinner oil in it and see if that helps out next spring.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

I might charge the battery and do a load test on it before trying to use it the first time next spring. You might also consider turning the engine over by hand when you stop using it. In the late fall.

Then before anything else see if it can be turned over manually as easily as it was next spring. . For example you could have even the alternator sticking after a winters vacation. Usually in my experience it take a longer period on average for engines to stick. Especially diesels. There are of course exceptions.

Another concern is some coolant might be leaking into a cylinder very slowly and rusting up a cylinder making it tight. You could drain the coolant each fall to avoid that possibility. It would not take much internal leakage to cause an issue.

Also the modern battery or most of them really do not tolerate non use that well. At least in my experience. Still all things considered I do not suspect your battery especially. Yet it still could easily be the candidate.

There may be climate issues in my region that make my experience with batteries not that great. This year was exceptional in that our lawn tractor batteries were still good. Both are a few years old now.

Actually other members will probably have more realistic ideals.

I should include a word of warning. In my experience letting the newer cars sit unused. Too many of them will seize their alternators. I think the clearance between the rotor and stator has been reduced over the years. Increases efficiency but adds an issue.

Probably not an issue in a dry climate. It is a very real one on the east coast of Canada. With certain brands of cars you can almost count on this occurring beyond a couple of months of non use.

Perhaps I should also add. A fully charged battery may read 12.75 volts. That is just a confirmation that the battery is fully charged. It in no way gives you any indication of what amount of current is stored. For example a badly sulfated battery could read 12.75 volts. Yet could not crank and engine. It just is unable to deliver enough current.

Absolutly nothing is written in stone. I had a parts lawn tractor sitting around for about five years. I do not know why I tested the battery after that much time. It was not too bright to think it might still be good.

Suprisingly it was. I just went and looked at it. It is a workaholic by interstate. Two hundred and thirty cold cranking amps. I posted this information because there is a very slight chance it might be a better battery. It should have on average again been bad.

I'd clean the cable connections well and try it again.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Because I disconnect the battery at least once a year, I know battery connections are good. I also checked the ground. After the initial slow turn symptoms, everything works well for rest of summer.

Diseasel300: I put in fresh oil each Fall and it lasts for the summer. In past, I used Mobil TDT 5W40. But I couldn't find this in recent years, so used 15W50 which I had used in past. Temperatures in early April are probably in mid 40's (F). It could be that a different oil might help.

On my marine diesels, when it's cold, I sometimes operate the decompressor lever that they have and that would allow the motor to spin freely. After that starting is easier. I guess, turning 300D engine over by hand a bit is an option, but not sure it would be enough to loosen things up. Maybe starter needs a good spin. My engine usually starts (or not )as soon as I turn the key. Thinking that I might prevent engine from starting first time (using stop lever) and get starter to at least rotate a few times?

Barry, regarding battery voltage. I always charge before starting for first time. Voltage is good and I did do a load test that showed battery was still good. Battery is about 4 years old, so it could be getting a bit tired. But seeing it is now working fine, no rush to get a new one!

Thanks for the input!

__________________
Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I figure I would add my $0.02. My 1984 300D is a daily driver. I have been regularly out of town and not driving it for up to 3 weeks at a time. Each time I start it the first time, I notice it takes a little extra to crank it, the engine runs a bit rougher and the power steering is not as responsive. After getting it to freeway speeds, it always comes back to normal the next time I start it. I think this is a real notable difference in having a car without a computer to "adjust" for irregular values being reported by sensors.

Dkr.

Synthetic oil has made the 84 & 85SD easy to start in the winter time. The 85 had recently been sitting outside for several months with the battery disconnected. It cranked right over after charging the battery. I expected the battery to need a charge and didn't test prior to starting.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

just because your battery has enough voltage doesn't mean it has enough CCA to start the car.

turn the engine by hand see what happens. also check the CCA.

__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

That's why I did the load test!

__________________
Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I perhaps was not clear. When engine is cold estimate how much effort is required to turn it by hand. This is in the fall. A duplicate test just before attempting to start next spring. You will have to have a lot stiffer manual turn over present to make a starter notice it. It will be enough differance for you to mentally compare after that length of storage. If it is engine or accessory related. Or the battery.

As for my own experience. If you have been doing this with that battery for 4 years. If it were my car and battery. I would immediatly suspect the battery.

This is a diesel starter. My load tester heats up as well. The starter may even be a heavier load than the load tester. So it may not reflect the service the battery is really required to deliver.

You will know the situation better next spring. If the engine is no worse to turn over by hand. Then it cranks even harder then you can almost assume the battery is suffering damage sitting each year.

Depending on climate and perhaps a few other things. An average car battery lasts no more than 6-7 years usually in regular service. If it is deep discharged many times. Or you leave it sitting idle for long periods of time. The overall useful life will usually be shorter.


There are exceptions but in general these factors have caused me many issues with the newer batteries In the last 25 years or so. It has not been unusual for me to visit private car collections and this area in conversation comes up time after time. Many try things like trickle chargers and other things. We all seem to lose batteries quicker than we like.

The United States navy uses the only real approach that does work. They also get many more years of service out of a battery. When the battery is to be out of service for quite some time. They drain the battery and store the eletoylite until they want to put the battery back into service. This is hard to do with our car batteries. Not impossible but harder. Their batteries would have individual cell drains.

You would have to drain a car battery into a large pan using a full mask and other protection from battery acid. Wash the surface of the battery off after putting the cell plugs back in. Store the chemical it in a non metal sealed container and reinstall it next spring.


You then add the length the battery was drained to the average lifespan.
So a car in use six months a year and stored six months. The battery might last 12 to 14 years. As soon as you put the acid mix back in you have a battery at the same level of charge as when you drained it and no sulphating issues have occurred with the plates.


There are specific high tech chargers that claim to give you the average lifepan. Like many things I have no ideal if they really work. The only certainty is in a case like I describe they will not give you the 12-14 years of service.

This is just some food for thought as I cannot see people draining their batteries for storage unless they become substantially more costly. Also if you look at batteries for sale they will have a date that they are not supposed to be retailed beyond.. They used to come in dry and the acid was added at the time of sale. Now they come in wet. So always look at the back of the rack for any that may have a later date than the ones up front. I still do this but our battery type for these cars is no longer usually stocked in any form of depth anymore where I live.


Since big chains probably do not pay for product until it is sold. What happens to the batteries that exceed the date and are pulled back off the shelves by the suppliers. Although I guess they are cautious in trying not to supply stocking levels that create this issue. Are they then sold as seconds by independent vendors? I do not know.