Peco

Hello!

My son is 15 and was gifted a 2000 ES300 with several issues, and while I'm not really sure where to begin with it all, I figure the draining batteries are a good place to start.

If I crank up the vehicle once a day and drive it around a bit, the battery will last weeks. However, if I go a week without touching it, the battery will be drained.

I know nothing of the history of this vehicle. It could have been flooded for all I know... But it starts fine (with some sporadic misfired) and drives fine (with some hesitation / popping going into Drive). It's missing the front-passenger corner light housing, and rear driver's corner light housing, though both sockets and bulbs are in tact.

In troubleshooting the transmission issue, I reseated the solenoid harness to the transmission and I feel that has lessened the issue, as it now shifts into Reverse just fine.

Anyway, can you guys advise on a good place to start in troubleshooting the electronics in this fellow? Or any other troubleshooting I can do to narrow it down? The vehicle isn't road-legal yet, so I can't really drive it to an auto parts store for CEL.

Thanks in advance!

LeX2K

At minimum you need a code reader and a volt/ohm meter can get both on Amazon for about $35. Once you have both report back.

Peco

OBD2 reader came in today and a scan registered 1 code: P0305 Cylinder 5 Misfire.

The misfire is very obvious when driving it around and I was going to look into plugs / wires. Which looks like a pain! ha

I tinker and (even sometimes!) repair old electronics, so I have a multimeter around. Where do you suggest I prod?

LeX2K

Check battery voltage with engine warm and running, both with no accessories on, then with fan at high and rear defog on. Swap coil #5 with one from the front bank see if the misfire moves.

Peco

Running without accessories - 13.3vdc
Running w/o acc at alternator - 13.5vdc
Running with accessories - 12.3vdc

Will swap the coil over the weekend and send an update! Thanks for all the assistance!

EDIT** This is with a brand new battery.

LeX2K

Assuming your volt meter is accurate those readings are marginal to bad. But the stock alternator is under powered for the car this is a must upgrade IMO (bolts up no mods)
https://www.rockauto.com/en/moreinfo.php?pk=870558

Peco

Voltmeter is a Klein 330. Its been pretty solid so far.

That Denso alternator is higher amperage to better handle the load? I did notice that I could not turn off the headlights. Even with the switch moved from AUTO to OFF, they remained lit. Is this normal for this vehicle?

I had wondered if underpowered transmission solenoids could be the cause of a rough shift into Drive. Is that a possibility?

LeX2K

Low voltage can cause all kinds of issues including misfires, bad shifting and in general poor mileage and performance. No it is not normal for the lights to stay on no matter the position of the switch at least not on my Canadian model. The upgraded alternator solves a factory flaw with these cars, the stock unit simply does not deliver enough power.

Peco

Got a chance to replace the alternator today, it actually seems to idle rougher now. Misfire and rough shift into Drive still present.

hot voltages -
13.78vdc
13.64vdc w accessories on

cold voltages -
14.05 off
12.83 engine running

i haven't swapped the cylinder 5 coil yet, but will next time I dig in.

any good next steps for diagnosing this guy?

Peco

Bump for a check in on those voltages. Do those look better?

Also, does anyone have a link to a wiring diagram? I'd like to trace those headlight wires down and see what's keeping them on all the time.

Arsenii

Hello,

The voltages look good, it's the Parasitic Draw test that is more important at the moment, since no matter how well the battery is charged, it will drain out if some kind of draw is present in the system.

By the headlights being on all the time, do you mean Daytime Running Lights or those staying on even after the car was locked for some time? Those cars are equipped with DRLs, meaning that the headlight would turn on after you release the parking brake and stay on until the Ignition is turned Off. If that is not what you are referring to, please elaborate on that issue, since it could actually be a source of your draw.

Hope this helps and best of luck!

Oro

Not entirely sure what that means; "hot" and "cold" voltages really aren't a thing. If you are measuring across the battery terminals and seeing 12.83V with the engine running, you have a charging problem.

With the meter's leads across the battery poles, read the voltage at with the car at idle and then when revved up to 2k or so. Read the battery a few hours later after sitting w/o running. Then, w/o starting, let the car sit over night and then read the battery voltage in the morning before starting the car. That will give useful numbers. The first two numbers will give you (some of) the alternator health, then the next two will show the battery's health.

LeX2K

Probably a "parts counter" alternator I've lost track of how many times they don't work properly out of the box.

Oro

I put the fourth replacement alternator in the ES300 a few weeks ago since 2015, all O'Reilly 'Ultima' or whatever. I posted about it on BITOG:

https://bobistheoilguy.com/forums/th.../#post-6223022

Here is the pertinent info:

Hayk

iTrader: (1)

I wanted to add that a parasitic draw test should be next.

Also, you mentioned the car is missing housings for corner lights. That’s a major concern for liquid damage/corrosion to the sockets. Inspect the sockets to make sure there is no corrosion causing electrical issues.

Can you also upload some pictures of the car? It sounds really rough. Have you mentioned the mileage?