God awful high pitch squeal at idle {fuel injector seals}

[dtl1218]

Hey everyone,

I just got my 4g63t running in my '88 Mighty Max. I'm at least glad that it does run finally, but I have an issue to work out. I haven't made a boost leak tester yet, and that may help me diagnose this problem, but I wanted to post to see if anyone else has experienced this. I haven't gotten my engine idle speed set yet, because I need to work through this problem first if I want to save my ears. I have a very low idle right now, but the sound occurs when the engine passes around 500 rpm, and it continues up the range. If I rev the engine, the sound disappears while I am pressing the gas, but returns once I let off the gas and continues until the rpms drop below 500 rpm. It may be some sort of leak, but I'm not sure. I'm still new to these engines, I know now how to install one in a different vehicle, but this is the first problem I've ran into now that the engine is running. I've tightened all clamps very tight, and I came across another post while searching about a high pitch sound being related to throttle body gaskets or seals. If anyone can help me out, I would surely appreciate it. Plus, the sooner I can fix this problem, the sooner I can post burnout pictures here since I have the four stock wheels and tires that I replaced, and they're begging to be burned down!

Thanks for any help!

David

 

[talontsi9095]

I would do the boost leak test but also check your belts ive heard that sound from there in the past.

 

[justin0469]

Probably belts

 

[dtl1218]

I'm only using one belt for my truck setup since I don't have power steering, so the only parts that are being turned besides the timing parts are the crank, water pump, and alt. I took the belt off and let the engine run for a few seconds and the noise was still there with the same conditions. I think it has to be airflow related because the sound disappears when I 'blip' the gas, it may be a minimal amount of air pressure building up before the throttle body butterfly and leaking out somewhere. It would really make your ears bleed, its such a shrill sound, worse than fingernails on a chalkboard. I took a video with my phone earlier today that has the sound recorded, but the video format can't be played on a PC, I'll try to take a video with my digital camera soon if I can't figure it out.

David

 

[justin0469]

High pitched sound could be a pinhole leak as well. You said you took "the belt off". Like one belt, the alternator and water pump and crank are on one belt right? I'm just not sure if your unique application would change that. The most common belt that gets loose and slips and squeels in the alternator belt (it seems that way to me anyways). If any of the pulleys are too tight they will make a squealing sound as well.

 

[talontsi9095]

Also your water pump may be going out unless you replaced it.

 

[dtl1218]

I did take off the one belt I'm using, and the noise was still there. The water pump is new, so hopefully it's not that. I probably do have a pinhole leak, I'll be making a boost leak tester soon, and I'll probably rub the pulley surfaces with sandpaper to give the pulleys a little more friction just in case the belts try to start squealing.

Thanks!

David

 

[Lordpaxin]

Once when I was helping a friend Clutch swap his Saturn, The Access plate on the bottom got bent lighty and would Rub the flywheel (at certain speeds) this created a real loud High Pitched Noise.


Doubt its your prob tho

 

[dtl1218]

I wanted to post what the problem was for future searches.

The problem ended up being that I incorrectly installed the fuel injector seals by not placing them on the injector first, and I must of had a vacuum leak that started only when the engine started to warm up and the rubber seals expanded a little.

David

 

[andymoraitis]

Interesting as I was just about to recommend that you check the injectors seals in the rail and head. I've made the same mistake myself and created similar noises that took me a week to track down.

Glad you got it fixed.

Andy

 

[trapspeed]

I wanted to post what the problem was for future searches.

The problem ended up being that I incorrectly installed the fuel injector seals by not placing them on the injector first, and I must of had a vacuum leak that started only when the engine started to warm up and the rubber seals expanded a little.

David

I've done the same exact thing in the past. Glad you found the problem because that sound is definitely annoying.