petrock

After changing the oil on my wifey's mustang today, I started the car and let it sit a while to check for leaks etc. When I shut the car down I heard a gurgling sound and then a rattling sound coming from the passenger side of the engine bay near the firewall. It started a couple seconds after the motor stopped rotating and lasted for about 5 seconds. The motor would stop rotating then a second later the gurgling would start for a second or two. When the gurgling stopped the rattling would start. With a mechanics stethoscope, and my wifey turning the car on & off, I was able to narrow it down. The gurgling is coming from the EGR Solenoid and the rattling is coming from the PCV valve. The PCV valve is rattling because a vacuum is started/stopped pretty quickly making the plunger in the PCV valve jump around & rattling in its housing. I have no idea what is causing the sound in the EGR Solenoid.

No codes are being thrown, btw.

Any ideas?

petrock

bump bump bump...

petrock

Anyone?

Daehawk

Sorry you're not getting replies. I keep checking the thread though. It's a curious problem.

Matt's 95 Stang

Sorry I have no idea but will watch the thread in hopes someone can help.

Matthew

petrock

I haven't had a chance to get near the car since I posted up this thread so I'm not really any further in figuring this out then I was when I initially posted this up. I've been out of town most of the month.

However, after noodling on this a little while, the PCV valve rattling is definitely from fluctuating vacuum bouncing the plunger in the PCV valve metal housing. The question is what would cause the fluctuating vacuum _after_ the motor had been shut off? I would expect it to just drop off quickly. I can't remember if the motor had fully stopped spinning, or if it was spinning down, or if the motor was hot or cold at the time. Could a vacuum leak or clogged vacuum line in the PCV system cause this?

As for the gurgling, I still have no idea. The EGR Solenoid is computer controlled to apply vacuum to the EGR valve. If the gurgling was due to oil/liquid in the tiny vacuum lines attached to the EGR Solenoid, I would expect it to not allow vacuum to the EGR valve so it wouldn't open as much as it should (if at all). Wouldn't that cause drivability issues or throw a code? The car runs like a top with no idle issues or codes either.

I'm a proponent of diagnosing a problem and fixing it correctly & once rather then the shotgun approach of throwing parts at a problem till its fixed. I don't have the $$$ for the shotgun approach.

Any ideas or tests I can run to help diagnose the problem?