Question (but not S2000)

[rockfish]

I've got a question about my non-S2000 DD POS. It is a 92' Maxima SE.

The brake light & battery light came on this morning and would only go off if I rev'd the engine above 4000 RPM.

What do you think?
- Bad alternator
- Belts too loose
- too much oil spewing on alternator
- too much oil spewing on the belts

[bimdub]

I've got a question about my non-S2000 DD POS. It is a 92' Maxima SE.

The brake light & battery light came on this morning and would only go off if I rev'd the engine above 4000 RPM.

What do you think?
- Bad alternator
- Belts too loose
- too much oil spewing on alternator
- too much oil spewing on the belts

all foue things going on...leads me to believe it is probably the Alteranator.....you can get it tested. if it tests bad...you should consider fixing the leaks as well because that oil leaking onto the alternator will make it fail premauturely!, this of course would not explain the brake light? unless the two are right next to each other and the light is just transfering across.....but then you could have some brake problems at the same time as well....when it rains it pours? the brake light can be as simple as low fluid...but then that could indicate a leak? and even then if the fluid is low its a good idea to check for wear as the fluid level drops in the master to compensate for wear....and heck to be 100% honest.....it is always good to replace (flush out) all the fluid in your braking system every two years at least! BMW actually suggests this as an annual service, and if you use ATE fluid you can make it really easy....;.I use ATE super blue on even years and ATE super gold on odd years....they are pretty much the same fluid but color coded for making flushing easier!

[repiv]

It's likely this car has a vacuum boosted brake system. At low rpm, there may not be enough vacuum to create enough boost. You may have a leak in the boost system or the booster is just old and tired. Check for leaks in the hoses (cracked or disconnected) and in the unit itself. There may also be some kind of one-way check valve. That might be the source of the problem as well.
As for the battery light, it should be easy enough to check for belt tension. If that's good, then check the battery voltage at rest and right after you do a cold start with all accessories off. The battery voltage after sitting overnight should be around 12.5V or higher if it's in good condition. Right after the engine fires up, it should be running at a slightly elevated rpm (cold idle). Chech the battery voltage again (across the terminals). If the alternator is in good condition, it should read between 13.5 to 14.0 volts. This should help you narrow down which one it is.

[rockfish]

Thanks guys.

The brake and battery lights are actually tied to the same issue. On this car the brake light will illuminate when you first turn the key and if the battery voltage drops too low. I'm not sure why it does this, but I guess it made sense to the folks in Yokohama.

When I rev the engine, both lights go out at the same exact time.

I'll check the voltages. I think my best case scenario is if I can clean the engine up and the issue goes away. I'm selling the car in the next couple of weeks and don't want to invest in replacing the valve cover gasket. I've bought some engine cleaner that may wash some of the oil off the belts and alternator. If that doesn't work, I'm guessing it is the oil-soaked alternator.

[rockfish]

12.1v

[repiv]

12.1v

Is this first thing in the morning after the car has sat for many hours? 12.1V is on the low side. Might just be your battery is getting old.

[S2Kouichi]

By brake light do you mean the warning on the dash or the actual lamps in the back of the car? I had a problem with a 91 240SX where the brake lights in the back never turned off, traced it down to a rubber plug that was supposed to rest against a switch to turn it off.

You seem to have other symptoms, though.

[rockfish]

12.1V was after driving to work. It was 12.4V before I cranked it.

Got the alternator replaced and it seems to be back to normal.

Thanks everyone.

[Goku]

Is this first thing in the morning after the car has sat for many hours? 12.1V is on the low side. Might just be your battery is getting old.


!!!

I have to strongly disagree. I know this problem has been sovled but a battery sitting at 12.1v over night is nothing to worry about. Anything under 11v would be something to worry about. You average battery will test anywhere from 12.0v to 12.5 after sitting. But 12.5 would have to be a good qualty battery. You have to remember that the battery he has in that car is probly only a 450-550 cold cranking amp battery. Sorry to go on a rant about this(im a automovtive electrician) but I didnt want guys to go out and check there batteries tonight and replace them cause they are sitting at 12.2v...

[rockfish]

For me, the key was that the battery voltage was unchanged when the car rev'd up. It could always be something else, but as long as the battery isn't a dead short (should look like a capacitor), then it seems like the voltage should increase when the engine is running.

Does that seem reasonable?

So, Goku, what do you think about oil soaked alternators? Possible cause? It wasn't too many years ago when I had this thing replaced previously.

[Goku]

Oh I agreed with what you replaced. when I first read the thread. I've seen that many times with the light going out at higher rpms. Usualy one of the lower staters has failed and the 3rd one is still working, but it only works at high rpms. replace the alt, problem solved. But repiv is only giving out advice on how to check other things before you replace the expensive part. I was only disagreeing with his voltage numbers nothing else

[rockfish]

Interesting. I have never seen this thing with the high rev’s . . . but maybe that is because I never rev’d thinks up. Maybe my rev-happy S2k has gotten me to push t:revto9k: he limits.

This is the 2nd alternator I’ve put in this car in the last 3-4 years. Any thoughts on why it keeps going?

[Goku]

well as I cant say for quality of the alt to begin with 3yrs is a pretty good time frame. But do you have anything extra in the car. Stereo. something like that. I remember my 86 prelude would burn threw a alt about every 2 yrs. But I also drove the piss outa that car.

[rockfish]

Everything is stock except a 6-disc changer in the trunk.

[repiv]

For me, the key was that the battery voltage was unchanged when the car rev'd up.

This is usually an indication that the alternator isn't putting out enough.

[Goku]

Yea repiv is right. Its also the easy way to check your alt. If your charging about 13.5 - 14.5v then your alt is doing good. But if you see it under 13v you got a problem brewing. If you see 12.5v or less while the car is running your alt isnt working at all or is barely working. And should be replaced to avoid damage to the battery.

[rockfish]

Well, the repair seems to have worked. No more battery issues.

Now I’m trying to sell the illustrious POS. I’m selling it on Craig’s list and am surprised by how well it moves. The first phone call was 15 minutes after posting. They offered (low) to buy it without seeing it. Of course, there are a bunch of cheese balls who are asking me to bid against myself. As soon as I tell them they have to make an offer they lose interest.

Anyway, if anyone else is trying to move a POS, Craig’s list is a great place! I was expecting it to take a couple of weeks and it looks like it will just take a couple of days.