Been noticing a bit of a delay when starting my gl450 recently, so I decided to go get the battery checked. Took it to Autozone, and they connected their testing unit to the terminals under the hood on the passenger side. 208 CCA. Awesome. So I bought a new battery.

Replaced it, and started the car. I mean, it started fine...there was still a bit of a delay, and I noticed the delay was less if I shut the car off and started it again (but this was a test that I never really did before, so not sure how normal that is). But in general, I feel like I still have a 2 second (ish) delay when turning the key and the car turning over. I don't know with a 2011 GL450 if it should be super quick, or the delay is completely normal. Can someone confirm? Before the battery change, it was probably closer to 3 seconds.

So...I got a little curious if maybe the battery I purchased 'maybe' was also bad, so I took it back today to get tested. She connected again to the terminals under the hood, and it came back "Bad battery" and CCA of like 420. Hmmm.

She asked if she could connect directly to the battery. So I got behind the seat, took all the stuff apart, and gave her room to connect her tool. She more or less got the 900 CCA she was supposed to get (I think one time she actually got almost 1100, which was odd), but the other time was like 925. She then tested the starter and alternator from the battery directly..and she said those appeared to be coming back good. I believe the starter was coming back as 11.4 amps (?) out of 12.4 or something.

One final test, she tried the terminals under the hood again, and it was CCA of 520.

So...why would I be getting such poor reading from the terminals under the hood compared to the battery? And if so, how do I resolve this?

 

The only very-low resistance path from the battery is to the starter. The terminal in the front is not connected to the battery with as heavy a cable, so you won't get the same current. That's normal.

Is the delay in starting before the engine starts to crank? Or does it take a couple of seconds of cranking to start? If the latter, it's often a sign of a failing crank position sensor.

 

It starts to crank right away when turning the key, just is 2 seconds of cranking till ignition.

So how does one check the battery without going to all the trouble of taking apart the pieces behind the seat to test for a bad battery? Is there a level of CCA from the terminal in the front that is deemed "acceptable" for a "good" battery vs a "bad" battery, some ratio?

For example, if I am getting 500 from the front terminal, that would give me a % of 0.55, but when I got 208, that was 0.23. (when dividing by 900)

 

1,000 amps takes a very thick cable to travel any distance. It's WAY more than the starter draws, so it's really only a theoretical value except for testing the battery, which must be done at the terminals. Any real-world cable will have too much resistance to allow anything like that current. The one thick cable that runs from the battery to the starter will probably have an ampacity of less than 500 amps. The cable that runs to the under-hood terminal will have way, way less.

Ohms Law is your formula, but measuring the tiny resistance of these cables accurately is not practical. But, as an example, a 10' 2/0 gauge cable carrying 1,000 amps will cause a voltage drop of 13%. That's probably a reasonable approximation of your starter cable. On the other hand, a 6 gauge cable will cause a voltage drop of 66% if you tried to draw 1,000 amps across it. You wouldn't get close to that current. But in real-life, you don't need to so the wiring to the terminal up front is adequate. But not for trying to test a battery. The only way you can do that is at the battery.

I really think you're barking up the wrong tree.

 

Yea fair enough. Thanks for the electrical explanation.

I ran a code check recently and didn't get any P-xx codes for the crankshaft position sensor. Again, with a 2011 gl450, I don't know if a minor delay is perfectly normal or these engines are supposed to kick in right away after turning the key. It doesn't feel like a bad delay or anything, but like most car issues...when you start wondering if something is wrong and you change a part, then you start focusing on it.

 

So this is not my car, but it looks almost identical to it and same year. This is how it sounds (in terms of the delay) of starting. Perfectly normal?

 

@majorchamp please post a video with sound showing your ignition key/button actuation and the tachometer.

 

Here you go
Note: this was after 2 prior ignitions because I screwed the recording up, so it's "slightly" quicker..but honestly not too far off in speed/sound.

 

That model doesn't have auto stop/start, does it? If not, that seems fine. The auto start engines usually start on the first tick because they have extra smarts to deal with the constant restarting. But for a pre-auto start engine, that seems fine.

 

That is correct, turn key.

 

No, I don't mean Keyless Go. Auto start is the feature of new engines that shut down at stop lights and restart as soon as you take your foot off the brake. It's mainly a nuisance but it does save a few teaspoons of gas a week. But it involves engine modifications that make starting very fast. The computer knows where all the valves and pistons are and squirts the appropriate fuel injector first when it restarts. That's why these new engines start so fast. But a couple of rotations of the engine is nothing to worry about for a pre-auto start engine.