08 G35 Sedan, 152K miles.

Over the last couple days, noticed the G was getting slower to crank but would start and run ok. Yesterday parts store load tested battery, alt and starter(voltage to starter only), all tested good. This morning G barely started, cranked over slowly and finally started after ~4 cranks. Tonight the G will barely crank over 1 time and will not start. Placed battery on charger to re-verify previous test and battery indicated charged in ~1hr but still same. My guess is the starter but I have seen very few starter issues in the forums. Typically in previous experiences, starters were either good or would not start period. I have never seen one slowly degrade and eventually not turning engine over. Symptoms mimic a weak battery but all that is good. Leaning towards starter, any input?

 

Does it crank every time at least though? When my starter went out it was due to the bendix gear being sloppy. It would take several times to engage, because it wouldn't retract after it was cranked. Put a new starter in and my issues went away.

 

Remove battery cables, clean thoroughly with a brush, apply anti oxidation grease, and reinstall (yes both sides of the battery cables). Corrosion, a.k.a. resistance, directly affects power to the starter.

If it's cranking sluggishly that's probably not the starter, what "test" did the parts house do on the battery? Did they pop the caps, suck out water from each cell and actually TEST the battery (hydrometer) or did they hook up an electrical machine that doesn't actually test the integrity of the battery and wrongly tell you it was fine?

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My problem was similar and it was my starter. My old starter was moving in it out, as the solenoid has failed. Maybe that's your problem?

 

Hello,
yesterday changed my starter at 08 g35 sedan. Don't want to tell you how hard it was for the mechanic to get the starter out and replace. Symptoms are so tricky compared to low battery.
Note: starter when taken out was working, just when engaged to engine it will fail.
good luck

 

Starter now will not even turn engine over, but attempts to. Parts store load tested battery with hand held unit and was good, battery is only about 4 months old. All terminals are very clean, no corrosion. All symptoms mimic a low battery however its not. Possible the starter motor is weak or seizing up. That starter motor is on driver side and does not look fun to replace, just wanted to be little more certain prior to pulling starter.

 

The only other thing (outside of verifying fuses, relays, etc...), I would do is a voltage drop test to see if you're losing voltage at the starter (loss of voltage = weaker starter). If it's a wiring problem and you replace the starter it won't fix your issue. If that checks out, I'd replace the starter then. You could also just say f-it and go for the starter anyway.

They can work normally, but lack the power to actually crank the engine over.

Something as simple as a corroded terminal could cause a loss of voltage. Lookup ScannerDanner, Schrodinger's Box, or South Main Auto on YouTube for voltage drop tests. They have some real good explanations how to do it.

 

Test all your battery cells with a battery hydrometer



Just because your battery is four months old doesn't mean it doesn't have a defective cell. Did you check the date code on the battery?


Telcoman

 

Update: All voltage testing was good. Proceeded with starter replacement. Unfortunately steering gear and linkage must be dropped in order to remove starter from engine bay. This is not mentioned in FSM. PITA. Needless to say, parts were reassembled and taken to local shop as I did not want to embark down that journey. Starts like a champ.

 

Yeehaw, glad you got it working again!