Karanx7

iTrader: (2)

My car has been having a pretty unusual symptom for a long while now. Right after coming to a stop for a couple seconds, the car will kind of hiccup. All of the lights (interior and low beams) will dim significantly, and the car will inch forward despite me not easing off the brake. It doesn't lunge forward or anything, so I just press the brake a little harder.

I think that the car is trying to turn on the second radiator (the one that is used when the car is not moving). From what I understand: when there is no air being channeled through by the movement of the car, then the second radiator comes on.

Now that it's not hot as balls in Arizona, I stopped using the A/C. I noticed that the symptom completely stopped. So I drove with the A/C on and off, and observed. Sure enough, it only happens when the A/C is off.


I used to think that the inching forward thing was because of the brakes being affected, but I came to a stop on a really steep incline. I wasn't pressing the brake at all, and the car was still at a stop because of the incline. When the hiccup happened, the car still inched forward slightly. Weird thing is that the RPM needle is rock solid (maybe it's sticking though because of my reverse glow gauges).


Sorry for the wall of text. Any ideas?

sammy95

"Now that it's not hot as balls in Arizona, I stopped using the A/C. I noticed that the symptom completely stopped. So I drove with the A/C on and off, and observed. Sure enough, it only happens when the A/C is off."

I'm lost. Does the problem happen with A/C on or off?
If on, some dimming is normal, excessive may be abnormal. Were you low beams on? Sound system on? Anything with a draw will naturally dim lights when the A/C compressor is engaged. (Alternator also slows down for a half second). All that get's worse if you put a huge electrical load on the car.
It's possible your IAC MIGHT be sticking (not compensating for the drop of idle).
Or you may have resistance in your electrical lines from the battery, to grounds or power.

thelastaspec

Mine does this too, when the ac compressor kicks in (i think its a clutch). The engine calls up some more power giving you that lurch. I personally can hear it in park with my louder exhaust. This always seems to happen by chance when pulling to a stop. Check the alternator and stuff too in case its an electrical problem. Clean battery terminals etc.

01tl4tl

your understanding of the cooling system is incorrect:
there is no 2nd radiator (the heater core doesnt count for this discussion)

the driver side fan runs off a temp sensor to keep temp dead steady 1-2 lines below half

the slightest temp increase, say sitting at light for 2-3 minutes with water pump spinning at idle speed,,the fan will come on for 30-45 seconds then go off

Driver fan also runs to handle that sudden temp spike when engine is shut off
Should shut off in 1-2 minutes, if its running 10-15 minutes after engine shutdown,
you need a fan temp sensor `A`

the passenger side fan runs with AC ON, thats a direct connection- ac compressor shuts off when temp reached, fan goes off too
It will also run in an extreme overheat condition along with the driver side fan,,
but you should watch the guages and know thats happening = pull off the road

When you are stopped, little vacuum is being produced, which allows for the brake sinking
add load of ac kicks on and idle speed doesnt change, or is slow to react to AC on, and you will notice other symptoms

First thing I would do: get the battery and charging system tested,thats FREE at most parts stores
Replace the battery NEG cable and the small neg cables that attach from engine to frame
Acura has a complete kit for 20 bucks..makes a huge differance!!

Replace pos cable with one from parts store
ANY crud buildup inside or outside the wires,, and at battery terminals,, is reason to replace
plus they are 10 years old
The car needs good power and ground system for all the sensors to work right

beyond that, service the TB and clean/lube the IACV

ever seafoam the gas or manifold vac port?
miles on spark plugs, air filter etc?

Karanx7

iTrader: (2)

Ah shoot, I really messed up that sentence. I meant to say:
"Sure enough, it only happens when the A/C is ON."

Yea, I'm starting to think it may be the battery cables.

TB is clean, but I've never serviced the IACV. The car gets drowned in SeaFoam all the time, and I changed the spark plugs ~5k ago. Using a AEM V2 filter, and it's about time to clean that.


It isn't a normal surge though. All the lights dim VERY much. From what I read in Tom's post, it seems that the passenger side fan is causing the surge. When I come to a stop, the surge will happen within 3 seconds. Since it doesn't do this when the A/C is off, I'm assuming it's the passenger side fan.


I'll replace the cables and post back.