To start or not to start

I have a 1998 Subaru Legacy Outback that has been having a sporadic starting problem for almost two years. Occasionally and mostly when it’s cold, but not always, the car will sound like it’s going to start for a second and then go dead. I will have to turn the key over and over, sometimes many times until it “catches”. And so far it’s always started, eventually. I have a new alternator and battery, the belts are newer, a rebuilt engine with about 50,000 miles and have had the starter and relay system checked, which was okay. My mechanic, who’s been working on Subarus for years, is stumped. He says to wait until it happens again and have it towed in so he can look at the car while it’s acting up. Any ideas?

Assuming car runs fine otherwise, no check engine light on, no codes pending, and the car has had all the routine service done at the intervals recommended by the manufacturer, the engine has been recently tuned, and all routine maintenance is up to date.

Then suggest to your mechanic that he check

  • Engine coolant temperature and air temperature sensors
  • Timing sensors (crankshaft, etc)

“Dying” seems a bit ambiguous.
Just to make sure we have the terminology correctly: the starter is indeed turning the engine over but it doesn’t start, right?

Right, thanks. However the starter only turns the engine for a moment then stops. This can happen several times before it seems to “catch” and then turns over enough to actually start the engine.

Sounds like a bad connection on the battery or starter. Could be a bad battery as well, possibly the starter but we’ll assume that’s okay for now.
First check your cables and connections on the battery. Make sure they are clean and tight. You should not be able to move or twist them loose by hand. Also check the other side of the ground cable. It should also be tight and clean. There’s a fat cable leading to the starter. Make sure that’s clean and tight.

Next time you see it happen, get out a booster cable.
Connect /ONLY/ the negative booster cable’s lead to the negative battery post. Do /NOT/ use the positive lead.
Connect the other end (the negative side) of the booster cable to a large convenient metal part on the engine.
If it now starts without dying, you have a bad ground strap somewhere.
If it doesn’t help, see what happens when you boost the car.
If that doesn’t help, you may have a bad connection going to the starter or possibly a bad starter.

I suspect bad (corroded) connections or perhaps a bad electrical cable. The starter draws a lot of current and sometime the battery cables can deteriorate internally, under the plastic insulation covering. We are talking the really heavy battery cables here. Remove and clean the + and - contact points on the battery. On the ground cable (-) find where it connects to the motor and clean that contact too. The red (+) cable connection on the starter should be cleanned also. If any cable looks suspicious, replace it.

I think the multiple trys to start warms up the cables and eventually allows enough current to run the starter enough to get the motor started. How often is the car run? Daily, weekly, monthly? When started is the car out on the road for 30 min to an hour? Or, is it a short 5 min trip? The symptoms are consistant with a weak battery, or good battery that is in a discharged state.

Thanks for all the comments. I will check the things suggested. Uncle Turbo, I drive the car daily to go to work (20 minutes) or run errands (anywhere from 5 minutes to 5 hours). I do have a newer battery and it happens so infrequently (mostly in the winter) that I don’t think it’s the starter (and neither does my mechanic).