BLP

Falconbrother, thanks for the reply. I checked the tube that goes from the PCV Valve to the "gizmo" and it has no obstruction. The "gizmo" has suction on the port that the PCV valve connects to. The "gizmo" has a very small port on it that has suction on it. There are two small hard plastic vacuum lines that connect to this port. One goes to the passenger side at the firewall and connects to a what I think is a solenoid that has something to do with the heater system. The other one connects to a Box with an electrical connection, located behind the driver side headlight. Haven't been able to identify what it's called or what it does.

The "gizmo" is connected to the intake manifold on the driver side by two nuts on studs and has suction on both ports, so I think it must be getting vacuum through the intake but he haven't been able to ID what the "gizmo" is or does other than provide vacuum to the two locations listed above. It seems to me that this device provides suction on one side of the PCV valve and the engine provides suction through the valve cover on the other side of the PCV valve. These opposite suctions cause the PCV valve to move back and forth. I can feel the PCV valve moving up and down while the engine is running.

I did replace the adaptor tube that connects the PCV valve to the hard plastic tube that goes between the PCV valve and the "gizmo" along with the elbow that connects the other end of the hard plastic tube to the "gizmo"......seemed to make the sound a little quieter. Took it for a short drive and noticed the sound changed to a higher pitch "chirp" while in drive, at a stop or non acellerating low speed ......when I put it in park or neutral it changed back to the sound on the videos. I could not hear the sound if I was slightly accelerating, even at lower speed with the windows down.

I am concerned that driving it may cause serious damage to something. Looking forward to solving this mystery.

falconbrother

This is a little out of my league. It seems to me that the crank case is making too much air. Causes me to wonder if maybe the problem is where is sucking air in. When the piston goes up it tends to suck air in behind it and when it comes back down this causes the positive air pressure in the case. It's vented off by the PCV valve. There should be no positive pressure in the crank case. I had a 1992 Volvo 940 that had a complex PCV system. I ignored it and it eventually stopped working efficiently and blew out the front main seal. I was pouring out about a quart of oil every couple of miles. Lucky for me it wasn't the rear main seal which requires dropping the transmission.

There should be constant vacuum on the line that connects to the PCV as I understand it. If it has vacuum then maybe the issue is that it's making more pressure than the PCV system can handle. Maybe it would be good to check your cylinder pressures and see if you have blow-by coming around the rings. That would overwhelm the PCV system.

BLP

I used brake cleaner and sprayed it around the lower intake manifold and discovered a vacuum leak. I've removed and replaced the lower intake manifold and replaced the failing gaskets. It was throwing a random misfire followed by a cylinder 5 misfire as well as a high and rough idle since I bought it a few months ago. Then the strange sound appeared which brought me to this forum. When I sprayed the brake fluid along the edge of the lower intake I could hear it get sucked in around the cylinder 5 port area. This was confirmed when I removed the lower intake and found that the gasket was curved when installed and was sagging just over the top of cylinder 5 port ..... basically not sealing and creating a vacuum leak. In addition I found the water port seals were beginning to fail. Which possibly explains where the coolant was going and why the oil was turning dark soon after being changed.

I've attached some pics for you to see what I found.

So I've been working on installing the new lower intake gaskets (felpro ms98000 metal back instead of the plastic version) along with replacing the original spider injector with the new version and the upper intake gaskets. I hope to complete this project this weekend. Hopefully this will resolve the high idle, rough idle, random misfire, cylinder 5 misfire and strange squeal. I'll let you know how it turns out. Thanks.

BLP

Before and after cleaning

BLP

Pics of the block cleaned and prepped.

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Lower intake installed

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Updated spider injector Installed

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Upper intake Installed

falconbrother

Great work. Looks like you are willing to put the effort in. Kudos for that. Please lets us know how it turns out.

BLP

I completed the replacemnt of the lower intake manifold gaskets, upper intake manifold gaskets, spider fuel injector and valve cover gaskets. Fired it up, had a very low idle around 400 rpm....replaced the idle air control, fired it up and idle is at 800 rpm. Took it for a spin. No check engine light (random misfire, cylinder 5 misfire), no more high / rough idle and no more strange sound/sqeal. Now working on flushing the coolant. The Burb hasn't run better since I've owned it.

Here's a video of it running after the work was completed.