RTF

I have a 2003 Lexus ES300. I got this car about 3 weeks ago. Everything has been fine thus far. I've checked all the fluids. Today however, I tried starting the car, (after having driven it a little) and it would not start, the battery had to be jumped. I noticed after getting it jumped the RPMs were really low at idle, about 300-500. Normally they are about 900-1,000, or like 1,500 when cold, during idle. It seemed as if the engine was about to just shut off because the RPMs were so low. Driving it passed 60 MPH, I also felt a little, but noticeable vibration through the steering wheel and in the car. This isn't normal. I do not know what is wrong. The check engine light came on after getting jumped also. I took the car to autozone and got the battery tested, it came out at very low voltage, and "bad battery". I bought a new battery, switched it, and the car started right up, faster than it has ever started up, thank God. The check engine light was now off, (I do not know if it went off because the battery got taken out tho, and autozone said sometimes if the voltage is low from a battery, SOMETIMES it could cause the check engine light to go on, but I will still get the engine codes read and see what's going on). Anyways the check engine light is now off, the car starts extremely fast, better than ever before, but the RPMs at idle are still low, like 500 ish. I do not know why, also I will check to see if the vibration while driving is still there. Does anyone know what may be going on? I should be able to get a code reader to my car by Wednesday. Please help, sorry if there are forums already answering these questions, I'm a noob. I hope my car won't explode or crap out on me..

atlcal

Many times a failing alternator will cause a battery that is already on it's way out to fail Did you have Autozone check the charging system after installation of the battery? Low voltage will cause all sorts of issues, warning lights, driveability issues, and if the alternator has in fact faile, will eventually strand you somewhere. With the car off, you should be at 12.6V at the battery, with the car running, hopefully between 13.5 and 14.4 volts.

A digital voltmeter only costs a few dollars, and is a valuable tool for anyone interested in maintaining/diagnosing their car.

JetsonES

Upgrade your power wiring. At the very least the wire going from the negative terminal to the chassis. You can find premade cables at Wal mart or any auto parts store. Use at least 4 gauge but 2 would be even better. Be sure to sand down the point on the chassis where it bolts to to the bare metal for good contact. The stock wire is woefully inadequate.

You can also make your.own cables.from wire and terminals at home Depot or wherever but a premade unit will probably be easiest.

HomerJay

Good news, this is a common problem after the battery is disconnected. Usually the problem corrects itself after a series of drive cycles. Search CL for more info if the low idle speed persists.

RTF

Thanks you guys. I will definitely look into the suggestions, test the voltage and the cords and all that. I do think I may have overreacted though.. The new battery seemed to fix most of the issues, it starts instantly now, the RPMs still seem a little low at idle, but much better than before, and the car just feels healthier if that makes sense. But anytime somethings wrong I get worried, so I think I may have gotten a little over worried on this one. I haven't gone over 60 yet again since, so I'll have to see if I still feel vibrations. But thank you guys so much. I love this forum. Very helpful. I hope one day I can contribute as well

Zacharias

You did not answer altcal's question. Did AZ check the charging system when they checked the battery?


The fact that everything seems okay now doesn't necessarily mean it is. The brand new battery will make it look fine for a period of time, even if the charging system is weak.


If you aren't sure that AZ checked the charging system, go back and ask. They should have checked the system, but it pays to be certain.


A bad battery can kill an alternator, and vice versa.

JetsonES

You already contribute by giving us practice. I definitely noticed all sorts of wonky behavior out of my car before I did the ground wire, low idle, ac cutting out at idle, etc. If you want to do it right there are actually 3 wires to replace. The one from battery negative to chassis, the one from the alternator to positive, and the one from the engine to chassis. When everything is upgraded the car's electrical system becomes much more stable and less taxed. No "bottlenecks" so to speak. It's referred to as the big 3 upgrade, it's cheap and easy to do, and as these cars age and corrode it's really just a good idea.

RTF

Sorry about that. I don't think they checked that. They just checked the old battery, said it was bad and was getting a low voltage. I saw on their meter thingy that it was low and said "bad battery". Then I bought the new battery and nothing else was checked or tested. I will go back and ask them to test the charging system later today and I will update what they tell me.

RTF

I will definitely do it, anything simple enough for me to do myself that will help the car is worth it to me, but when money is a little more stable for me. And thanks, I'm glad I contribute in a way.

JetsonES

Yeah, no rush to get it done. I'm still only 1/3 of the way there but it will make a difference and should come in at well under 30 bucks, pretty good bang for the buck mod, might even pay.for itself eventually since the ignition is optimized and there is a chance you may pick up some mileage.

The other top bang for the buck mod(or tool) is an ELM327 Bluetooth adapter. It will allow you to read and clear codes, display a gauge for anything obd2 sees and datalog. They are 10 bucks and worth every penny. Again, it will pay for itself in just one or two trips to the parts store to get codes read.

Zacharias

No sorry required, my intent was not to jump on you.


I just wanted to make sure the loop was closed on possible issues. There is nothing worse than the relieved feeling that a problem has been addressed, when it suddenly turns to dread when the same thing reappears once more....

JetsonES

Don't you just hate that part of the internet? You can't hear the inflection in the words or see the body language of the other party so things get misconstrued very easily. Many times sarcasm and jokes just completely fall flat and sometimes people end up offended. Written language is such a crude tool but it's all we have in this format.

RTF

I never take anything personal, especially from the internet ha.


Yes I agree knowing something has been fixed provides a great sense of relief, but thinking something is fixed and finding out its not is very stressful.

I won't be able to make it to AZ today but will update when I get a chance. Been real busy lately

JetsonES

That's why I don't cut corners in labor intensive jobs by trying to reuse gaskets and seals. I kick myself in the *** forever if I do and it fails.