TheSpeedDemon

Tim, I got to tell you though I am not 100% sure the problem will not re-appear just out of the blue like it did this time. But like you, I am glad it was nothing major.

ArneeA

Let's hope that was all there is to it.

Benjamin Choi

speedy was so stressed out

Tippy

Steven, I dont think it is your problem but you did mess with the oil cap and the reason I am writing. You need to open the oil cap while the engine is running and make sure it DOES NOT affect the idle. If it sounds like it wants to die out or it does die out once you pull the cap, the oil separator has KO'd or possibly the bellow that returns the oil to the block.

TheSpeedDemon

Cory, thanks.

So how I understand this, whether I had a problem or not:

If I start the car, let it idle, remove the oil cap, the car should NOT die...correct?

If the car dies then I do have a problem...correct?

TheSpeedDemon

OK, so I started the car just now, a bit cold outside in the upper 40's in the garage. But it started fine and idled fine, however:

I removed the oil cap and the idle started to go rough. I didn't leave it off long enough for it to stall, but it was an obvious change in the idle. So is this normal?

Thoughts???

But I took it for a small drive, actually saw another 996 and waved and got a wave back , no problem detected during the drive. When I came to every stop sign or stop light the car idled OK, not rough, maybe a little low for my liking (600~700), but no stalling.

TheSpeedDemon

Bump because I haven't heard back from anyone regarding my last post

4-large

SD
I just went out and ran the car then took off the oil cap... dropped in idle and ran a little rougher! but did not die..See if yours will die

If I understand what Tippy is saying, If it dies, then the oil separator is bad or ???? is bad, the second part of the "or" I am not sure what he is referring to

Jerry

Tippy

If it idles relatively the same, your ok. There should only be a slight vacuum in from the oil cap.

If it is rough and dies out along with a strong vacuum on the oil cap, the separator has failed.

When mine failed, the cap was very hard to pull off and the engine died almost immediately, within a couple seconds. Once I put the new one in, there was a very slight vacuum when pulling the oil cap and the engine idle did not change much at all.

This diagnosis was given to me from 99firehawk.

Tippy

There is a rubber hose that is called the bellow (accordian shaped) that is part of the oil separator. It returns the oil dropped out of suspension back into the crankcase, sometimes these crack. I am not 100% on whether this would have the same effect on the idle though but I have heard someone here replacing like 3-4 on their car before, the thing is a PITA to get on the nipple of the crankcase.

ElTorrente

How does turning the air-conditioner on affect your idle? When I have my A/C on, the car idles smoother. It doesn't die or anything when it's off, it just runs a little bit rougher but no big deal - it's always done that as far as I remember.

TheSpeedDemon

Thanks much appreciated for the information.

So I started the car again, removed the cap and it didn't die although it seemed like there was good vacuum present, but not enough to stop me from removing the cap easily. So I am thinking it is OK, the idle changed very slightly.

Where abouts is the separator BTW?

I have no history on whether or not my car has had the separator or bellows replaced.

TheSpeedDemon

Yep I have the same results. A/C ON a little higher idle and smoother. A/C OFF a little rough idle but like you, no big deal unless it drops below 600 rpm's which it doesn't. It use to surge but then I cleaned the ICV and that cleared it up. I was even thinking to raise the idle a little but not sure exaclty what to adjust or if that is a good idea or not. This new issue seems to have been solved but we are determining whether or not I need to replace anything (i.e. separator or bellows).

Tippy

AWESOME, the separator is not your problem! The separator is on the drivers side, front of the engine. You can see it if the driver side rear tire is off.