Loud Squeal from Front of Motor - ZR-1 Net Registry Forums

Rumblin70SS396 · 08-04-2018

Hey all,

Trying to make progress with this car and it's just one thing after another.

Just replaced the oil lines which fixed my oil leak, but after it ran for about 10 minutes I started hearing a loud pitched squeal from the front of the motor. The car idles high (1500) which I believe is a vacuum leak but not sure what this now is. Oil level is fine with good pressure.

Service engine soon light is on which I will investigate later when the car and I cool down.

Any ideas? Bought this car 4 years ago and I have yet to put 100 miles on it.

Thank you,

Tony

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onetinsoldier · 08-04-2018

could be belt squeal ? Tensioner bearing ? compressor bearing squeal ? Alternator bearing , water pump …….I don't like doing this but try wd40 at each location to pinpoint it ! when it goes away you found it .

as for the high rpm ,possible tach is not reading correctly . theres a way to check ,if I remember correctly : you hold the ac fan buttons down(up/down) at the same time until the display reads 0 , then press the fan button in the middle till it shows 6 . then it will show you a number , multiply it times 25 and that's the correct rpm .

Rumblin70SS396 · 08-04-2018

Thank you for the reply!

After doing some research I can see it being any one of them. I definitely have a vacuum leak with the high idle. It's not like it's a little high with the idle, it's super high and almost impossible to drive.

I'm going to start by taking the air cleaner assembly off and retorque the intake bolts. It's a siamese runner intake so it leaks more than less.

Also need to check the codes and the SES light popped on today.

I'm out now but will post an update tonight or tomorrow morning.

Tony

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Rumblin70SS396 · 08-05-2018

Once I got home, restarted the car and no squeal. Let it run for about a minute and tried turning the headlights on in which squeal immediately returned.

I had to jump the car to start it's its been sitting so I fully charged the battery last night to see if that makes any difference.

Also had code 65 set which may be related to the vacuum leak.

Going to try the smoker today to see if I can find that leak.

Tony

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Paul Workman · 08-05-2018

Often sound echos around under the hood making it difficult to pin-point the source.

Marc Haibeck showed me a trick using a mechanic's stethoscope to find a the source of a squeal. He removed the diaphragm and steel probe section from the rubber tubing and just used the open tubing to poke around the various pulleys, etc.

In my case, it was the water pump. (The embarrassing part was that I earlier had convinced myself it was the power steering pump and had already replaced it...only to have the squeak return as before!)

32valvZ · 08-05-2018

If when you turned the headlights on, the squeal began, and you had to jump it.... sounds like the alternator to me.

emmvette · 08-05-2018

I'm going to give you something totally different, but easier to try to find. Check the seal around the plenum up top on all side. The fact that it comes on after it gets a little heat signals it could be that. You can try to isolate the noise by listening wyith your ear close all around the seal, but it becomes really easy if this is it, to find it with the mechanic's stethoscope. They are only $10 - $15 and will really help find this.

The correct fix is obvious, but if it's this type of leak you can seal it with another $10 or less of high temp tape. Push some electrical tape up against the leak, or better yet a small piece of high temp aluminum tape or self adhesive duct seal :-)

It could get you by for the summer.

I spent a lot of time and few dollars and had my alternator rebuilt to find out my noise was a plenum leak right above the alternator :-)

onetinsoldier · 08-05-2018

Spray some carb cleaner where you think there is a leak while the engine is running ,the idle will change .

emmvette · 08-17-2018

Did you figure this out yet? What did you find?

DRM500RUBYZR-1 · 08-17-2018

Quote:

Originally Posted by emmvette

Did you figure this out yet? What did you find?

Hopefully it was not a neighbor's cat.
Marty

08-04-2018	#1
Rumblin70SS396 Join Date: May 2017 Location: Delaware Posts: 48	Loud Squeal from Front of Motor Hey all, Trying to make progress with this car and it's just one thing after another. Just replaced the oil lines which fixed my oil leak, but after it ran for about 10 minutes I started hearing a loud pitched squeal from the front of the motor. The car idles high (1500) which I believe is a vacuum leak but not sure what this now is. Oil level is fine with good pressure. Service engine soon light is on which I will investigate later when the car and I cool down. Any ideas? Bought this car 4 years ago and I have yet to put 100 miles on it. Thank you, Tony Sent from my iPhone using ZR-1 Net Registry

08-04-2018	#2
onetinsoldier Join Date: Aug 2016 Location: Spring Hill, FL Posts: 127	Re: Loud Squeal from Front of Motor could be belt squeal ? Tensioner bearing ? compressor bearing squeal ? Alternator bearing , water pump …….I don't like doing this but try wd40 at each location to pinpoint it ! when it goes away you found it . as for the high rpm ,possible tach is not reading correctly . theres a way to check ,if I remember correctly : you hold the ac fan buttons down(up/down) at the same time until the display reads 0 , then press the fan button in the middle till it shows 6 . then it will show you a number , multiply it times 25 and that's the correct rpm .

08-04-2018	#3
Rumblin70SS396 Join Date: May 2017 Location: Delaware Posts: 48	Re: Loud Squeal from Front of Motor Thank you for the reply! After doing some research I can see it being any one of them. I definitely have a vacuum leak with the high idle. It's not like it's a little high with the idle, it's super high and almost impossible to drive. I'm going to start by taking the air cleaner assembly off and retorque the intake bolts. It's a siamese runner intake so it leaks more than less. Also need to check the codes and the SES light popped on today. I'm out now but will post an update tonight or tomorrow morning. Tony Sent from my iPhone using ZR-1 Net Registry

08-05-2018	#4
Rumblin70SS396 Join Date: May 2017 Location: Delaware Posts: 48	Re: Loud Squeal from Front of Motor Once I got home, restarted the car and no squeal. Let it run for about a minute and tried turning the headlights on in which squeal immediately returned. I had to jump the car to start it's its been sitting so I fully charged the battery last night to see if that makes any difference. Also had code 65 set which may be related to the vacuum leak. Going to try the smoker today to see if I can find that leak. Tony Sent from my iPhone using ZR-1 Net Registry

08-05-2018	#5
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Loud Squeal from Front of Motor Often sound echos around under the hood making it difficult to pin-point the source. Marc Haibeck showed me a trick using a mechanic's stethoscope to find a the source of a squeal. He removed the diaphragm and steel probe section from the rubber tubing and just used the open tubing to poke around the various pulleys, etc. In my case, it was the water pump. (The embarrassing part was that I earlier had convinced myself it was the power steering pump and had already replaced it...only to have the squeak return as before!) __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

08-05-2018	#6
32valvZ Join Date: Nov 2007 Location: Sunshine State Posts: 1,071	Re: Loud Squeal from Front of Motor If when you turned the headlights on, the squeal began, and you had to jump it.... sounds like the alternator to me. __________________ [B]1990 #2815[/B] [COLOR="Red"][B]Red/Red[/B][/COLOR] Ported Plenum & IH (by Pete) Haibeck Chip Rebuilt FPR (by Phil) FIC Injectors Watson LT Headers 3" Stainless Works exhaust Lingenfelter Open Air Lid Bill B Built Transmission Shifter & C Beam Plates [FONT=Impact][COLOR=red]1992 [COLOR=black]#[/COLOR] 091[/COLOR][/FONT] [FONT=Impact][COLOR=#ff0000]Red/[COLOR=silver]Gray[/COLOR][/COLOR][/FONT] [B]SOLD[/B]

08-05-2018	#7
emmvette Join Date: Jul 2013 Location: Central Iowa Posts: 190	Re: Loud Squeal from Front of Motor I'm going to give you something totally different, but easier to try to find. Check the seal around the plenum up top on all side. The fact that it comes on after it gets a little heat signals it could be that. You can try to isolate the noise by listening wyith your ear close all around the seal, but it becomes really easy if this is it, to find it with the mechanic's stethoscope. They are only $10 - $15 and will really help find this. The correct fix is obvious, but if it's this type of leak you can seal it with another $10 or less of high temp tape. Push some electrical tape up against the leak, or better yet a small piece of high temp aluminum tape or self adhesive duct seal :-) It could get you by for the summer. I spent a lot of time and few dollars and had my alternator rebuilt to find out my noise was a plenum leak right above the alternator :-) __________________ [CENTER][SIZE=4][COLOR=red]1990 ZR-1 Red / Red[/COLOR][/SIZE][/CENTER]

08-17-2018	#9
emmvette Join Date: Jul 2013 Location: Central Iowa Posts: 190	Re: Loud Squeal from Front of Motor Did you figure this out yet? What did you find? __________________ [CENTER][SIZE=4][COLOR=red]1990 ZR-1 Red / Red[/COLOR][/SIZE][/CENTER]