Terrible engine bay squeal, please help.

[armydoc]

I'm building a MK4 with a coyote engine and Tremec TKO 500 and I'm just at the rolling chassis phase (very exciting!). I fired it up and drove it around my block but then this terrible high-pitched squealing started. The car is driving and braking beautifully but this noise is turning my dream day into a nightmare.

I've uploaded a video to photobucket because I'm not sure how or if I can put videos on the forum. It's brief, only about 20 seconds but shows the startup and the noise that I'm talking about. Please take a listen and give me your best guess.

1 - At first I thought it was the belt or the tension pulley so I removed that and started it up again. Same noise, so I don't think that's the problem.

2 - I've read on other posts that it could be a vacuum problem. I'm not able to isolate the noise to one particular spot, but if I had to guess, I'd say it's coming from the bellhousing which is scaring me.

Here's the link: http://s110.photobucket.com/user/mightylad/media/IMG_0443.mp4.html

Advice?

[xatudor]

I couldn't see if you are running a brake vacuum booster but if so check you brake booster as it sounds like it may have a leak on the diaphragm. It maybe another type of diaphragm but it sounds like it is after a check valve which is why the sound dies down slowly after the engine stops. Good luck

[Jim Schenck]

Our first engine did that, turned out it was the breathers were plugged and the crankcase vaccum made that noise. We unplugged the breathers and the sound went away immediately. Hopefully that is the same problem for you.

[ClemsonS197]

The black hose with the white stripe. You have that connected to a vacuum port on the throttle body. Disconnect it. Cap the vacuum port. Route the hose to the air intake between the filter and throttle body or get a valve cover breather. Let me know if this works.

http://img.photobucket.com/albums/v296/FinlayZJ/CoyoteHose2_zps77f84d89.png (http://smg.photobucket.com/user/FinlayZJ/media/CoyoteHose2_zps77f84d89.png.html)

[armydoc]

Thanks to everybody who gave me input! As many of you suspected, the noise was due to my misrouting of PVC tubing and attaching it to the vacuum on the driver's side. For now, I have both routing to atmosphere and have capped the vacuum and PVC ports in the front but will order the fitting that goes into the elbow between the air filter and the throttle body that I saw on another post. I'm very relieved that it wasn't a mechanical grinding.

Although the engine is now running noise free, it is surging and has decreased power. Doing some reading I found that there is no vacuum from the back engine port (where I have my fuel pressure regulator attached) and that is probably negatively affecting my fuel flow. I am going to route it to the vacuum port on the front of the engine, do you think there will be any problems with that?

[Robert Andrew]

Can you imagine how difficult it would be to sort out a high tech street rod or muscle car without the benefit of the brilliant guys that take time to help on the FFR forum. Something as simple as that vacuum line routing could drive a guy crazy. There are certainly a great bunch of guys on this forum. There is hope for America:-)