This past Friday, I returned back from a week-long vacation and tried to start my 2005 TL. Unfortunately it had a very rough start. Literally. The engine sounded like it was stuggling to start, but it eventually did turn over. Immediately I noticed that the idle was very rough (at stops and also while stopping). RPMs at idle would be around 650-700, but often times dropping to as low as 500.

The next day, I tried starting the car and it didn't turn over the first time. I had to try another time before it started, but it also had a rough start, although nowhere as bad as the previous day.

The next two days after that, the starts got better, but the rough/low rpm idle remained. Fast forward to today, the engine would no longer turn over. At first it was the typical churning and then after a while, there was no more sound coming from the engine bay (my wife was trying to drive the car, so I wasn't at home).

Oh, and I should mention: The A/C fan speed appears to be wavering. I've never noticed this before. This scares me, because this may mean something else altogether...

So I guess my questions are:

1. Do you guys think this is the battery? Or something else?
2. Could the rough/low idle be unrelated to the inability to start the car now? In other words, I'm wondering if the rough/low idle is due to simply the car not being driven for a week.

Any thoughts would be greatly appreciated.

 

TLTrance, have the battery checked.
it should be at 12volts with the car off.

 

Do you have CEL codes? Sounds like an issue I had and it turned out to be the EGR valve. I had a CEL code of P0404. Batteries in our car have been known to drain. Another issue is the HFL draining the battery. Check the battery first.

 

test to see if you can honk your horn!

 

I'll check all of the above when I get home! Thanks everyone!

Even if this turns out to not be the battery, I'm going to get myself a portable charger so I (especially the mrs) won't be stuck anywhere due to the battery.. Not sure which one I'm gonna get though..

 

Your problem is a very simple one! Your battery is either going bad or is low on power/energy! The car's computer keeps certain data stored in memory that can be erased when it looses power or doesn't have enough power! One such parameter is the Idle parameter! When you are starting the car the battery is barely putting enough power to start the car, let alone the electronics to run it!

Once you get your battery charged up turn off all the accessories (A/C, radio, heated seats, etc) on your car and turn it off. Then turn it on and allow it to stay on for approx 10 minutes or until the cooling fans turn on and off twice! This is the idle relearn procedure!

 

Turns out it was the battery.. I bought a charger and charged it up and the car was able to start normally. The idle, however, is still a bit low.

I will definitely do the idle relearn procedure. Didn't know this existed!! Thanks csmeance!

 

Just to make sure I have the idle relearn process down:

1. Charge battery and turn on car
2. Turn off all accessories
3. Turn off car
4. Turn on car and let idle for 10 minutes
5. Turn off car
6. Turn on car and let idle for 10 minutes
7. Turn off car

Is this correct? Thanks!