looknow12

Our battery started getting a bit tired this winter. We have a 03 GX470. So tired that in trying to start, you could hear almost a back fire type noise but more of an air noise then anything.

We changed the battery at a local shop (I didn't even think if this was under warranty). Got the vehicle back and it is just as slow as it was before and we still get the same condition, back fire and all (when it is really cold).

Vehicle has 47k miles on it. Any ideas?

The G Man

Back firing noise is not cause by a battery. Possible cause might be the ignition system, have yoi change your spark plugs yet?

looknow12

Don't misunderstand me. It is not a backfire. I believe it is the result of an undercrank. The engine fires with less than normal revolutions from the starter. The result is a not so smooth start.

What are the specs for a GX470 battery, does anyone know?

koolaidman

if it sounds like a fluttering noise its due to the exhaust manifolds...depending on date of purchase u might be able to get 1 under warr

V8_Fan

Usually, it's heat that kills a battey long before cold does. When it's cold, it takes more CCA's to start up and the battery isn't able to provide as much charge, but a battery loses less charge just sitting there. When it's hot, the battery can output more charge, but also loses a lot of charge sitting there. I'm not sure which battery the GX uses, but the LX/LC comes w/ a big Panasonic battery that lasted me 4 yrs in So. AZ and others up to 8 yrs in less extreme climates. As mine wasn't able to hold a charge (left the car sitting too long...3 weeks, then driven once, another 2 weeks, then it wouldn't start up). I installed a mil-spec Odyssey PC1700MJT full metal jacket AGM (absorbped glass mat, 62 lbs!) last Friday, about 13"W x 6.5" D x 6 7/8" tall. You need to shim it (I used plywood) to get it to fit. This is supposedly one of the best money can buy in this country, and is used by law enforcement/fire depts, etc. Hopefully it lasts at least 4 yrs here in AZ. I keep a 3-stage charger on it now since my LX isn't driven for at least a week at a time.

loflin

Most modern ignition systems simply won't crank if the battery power (voltage) is too low.

In the old days, you could hear/feel the engine slowly crank, or you just got chatter on the solenoid.

Now a days, not enough battery left, lights and radio may work (for a while), but engine won't even start to turn over.

Think you have a different problem.

V8_Fan

My LX tried to start up w/ a near dead battery. You'd hear a series of a split second when the starter was on from the feature that keeps the starter on after releasing the key...battery couldn't put out the juice. The eye on the battery indicated "needs charge." It was just weak enough not to be able to turn the starter over continuously, but just strong enough to allow the starter to turn.

loflin

Yes, even in the current designs, there is still the inflection point where the sensing circuit, BEFORE the load is applied, detects enough voltage to allow power to the starter, but then as soon as the starter load is put on the battery, the sensing circuit detects the drop and kills the circuit.

My point was in the oooold days, as long you held the key the battery was connected to the starter and you could just hear/feel it grunt slower and slower, until the voltage dropped low enough it couldn't hold the high current solenoid and then the solenoid would drop out, dropping he load, the voltage would rise, the solenoid would re-engage, the load would hit, the voltage would drop, repeat, repeat, causing the dying gasp of a low battery to be the sound of the solenoid chattering....

V8_Fan

My 21 yr old 4runner does this. I was using an Optima blue top deep cycle/starter marine battery. When it died, instead of dying suddenly, it would progressively turn over slower and slower, as if you had a really heavy oil in the engine, yet it was 70F outside. Nice thing about that was it was a graceful decline, so you knew the battery was going to die, but had a couple of weeks to get a new one.