TOOK CAR IN FOR OILFILTER CHANGE AND MULTIPOINT ...
2008 Lincoln MKZ
December, 19, 2012 AT 6:35 PM
Took car in for oil/filter change and "multipoint inspection" performed at dealer. Regular maintenance only; functioning fine. Was told there was corrosion on positive battery cable, which they replaced for approx. $70. Next day car was slow starting. Minor electrical issues too (seats not auto adjusting, same with auto door locks). Within 4 days car would not start. Had battery jump, drove car to dealer, and was told battery needed to be replaced, at cost of approx. $170. Seemed odd, since inspection only days earlier included battery test and report indicated battery was fine. Should I continue to trust this dealer's service department? Is it possible they damaged my battery, or are being dishonest about performing the inspection the week before?
Your battery is at the age when it can be expected to fail due to lead flaking off the plates. When that happens, the charging current going through the plates has less material to act upon so they get hotter than normal and cause the acid to bubble excessively. That bubbling causes the acid to reach the underside of the top of the case where it splashes and condenses, and some of it seeps out between the posts and case. THAT is the cause of the corrosion around the cable clamps. When you see that corrosion, you can guess the battery is going to fail within the next six months, as yours did.
It sounds like a smaller wire broke off one of the battery cables and the generator is not recharging the battery. Evidence of that is that it took four days before the engine wouldn't start. The place to start is by having the charging system tested, but I'd have that done at a battery store, not the dealer. They will test the battery too. $70.00 is a lot to pay for a simple battery terminal cleaning, and they should be ashamed to charge $170.00 for a new battery. I recently bought one for my '88 Grand Caravan for $65.00, and it took less than ten minutes to install it. Most battery shops don't charge extra for installing one of their batteries, and some do the charging system tests at no charge if you buy a new battery.