Below is a short video of a noise my 85 US is making.

The noise seems to get loudest when my ear is at the front of the fuel rail on either side.

The car was not making this noise before the below maintenance.

Maintenance: I just replaced plug wires, distributor caps and rotors. I also replaced the temp II sensor. While performing the work, I noticed an unplugged vacuum line. To access the lines, I removed the fuel rails and loosened the first three intake tubes to access the vacuum line.

Plug wires are used Magnecors. Caps and rotors are new Bosch. About 1000k mi. after intake refresh, timing belt and waterpump replacement

Symptoms: Besides the noise, the car is running excellent. However, it is running a little warmer than before I performed the above maintenance. Idling, it runs just above the halfway line and just above the first line while moving. Prior, it idled just above the first line.

The noise does not start up until the car is fully warmed and sometimes cuts out.

Your good advice is very appreciated. I can record a longer video if it helps.

 

a whistle appears:
when dying Bearing
when damaged belt

 

does the noise keep in time with engine speed (rpms) ?does turning the lights on and off alter the temp reading you are getting?

 

The engine noise is independent of RPM.

 

I do have some belt squeal at startup.

 

Sounds like an air/vacuum leak. I recently did some repairs and attached vacuum that had come off the air pump diverter valve, among other things. After I finished I had a strange whistle noise on acceleration only after the engine warmed up. Pulled the vacuum off the diverter valve and plugged the vacuum line - strange whistle gone. Guess I need a new diverter valve. I'm not suggesting it is the diverter valve, but it could be whatever your detached vacuum line activates. Also, when doing intake refreshes, it's easy to knock a breather hose off the oil filler or throttle when reinstalling, causing a loud leak noise.

 

Thanks Bill. I am sure I could have easily knocked off something while moving those intake tubes. So you think a vacuum leak can make a pretty loud turbine sound? Also, is it possible an air leak could cause a slight temp increase?

I guess my next move is to start removing the intake and check all of the tubes and such.

 

I was going to say sounds like a vac leak to me also. small one drawing across an opening makes a whistling sound.

 

+1 independent of motor speed is likely a vac leak. Good luck hunting!

 

Thanks. I will get into the intake tomorrow and report back with success or request more suggestions.

 

Michael it sounds like a vacuum leak I would test any parts that are operated with vacuum use a mytivac to see if they hold vacuum otherwise one of the fuel injectors lower seals may be leaking or the plenum hoses may have been mis fit

 

Will do MM. Thanks.

 

I checked the vacuum lines and hoses and all are good. Since the injectors came out/went in so easily, I am thinking (also based on Mrmerlin's suggestion) it is time to reseal those. I did not do them when I did my intake refresh and it does sound somewhat like the whine/whistle before I did the injector seals on my VW Golf.

Anyone have a spare set of 85/86 injectors I can borrow or for sale for cheap for a WitchHunter core and service so my car is down minimally? Thanks.

 

Oh, so you reused the injector seals. In that case, there is a good chance a divot was taken out of one of the old, weak compressed seals on reinsertion. You have to be careful even with new ones - lube them and watch that all the O goes in evenly and does not partially hang up on the injector hole lip.

 

Thanks Bill. I did reuse them, twice actually. I pulled them for the intake refresh and again the other day to reinsert vacuum lines.

I am going to pick up a reseal kit tomorrow and redo them over the weekend until I can afford a new set of injectors. I used a thin coating of silicone grease on the O-rings when I did the intake refresh and will be sure to do that when I redo the seals and caps.