Unknown strange engine noise - ZR-1 Net Registry Forums

DarkAngel · 06-02-2013

Hello,

Ive made videos this week-end about a strange engine noise that i cannot identify

It appears when the engine is running and also when it stop, it makes a metalic noise like "rattle"
on the third video, we can hear it a little but usually it makes much more noise

The belt tensioner does not seem to move excessively and ive checked that the alternator and climate pump is tight correctly

If someone has an idea from where it can come from ...

Thanks for your help

1) http://youtu.be/OpJT7LIqf9M
2) http://youtu.be/Mc3TUkZx-zA
3) http://youtu.be/QFJsKHduLTo

geezer · 06-03-2013

Sounds like belt tensioner/ bearing. Easily available on the internet.
IMHO

scottfab · 06-03-2013

1. Remove the belt and inspect it for a bad spot.
2. Belt ok? then spin each, water pump, A/C, alternator, idler pulley and tensioner pulley as well as the PS pump. Listen and feel for any grinding.

DarkAngel · 06-03-2013

thanks for your answers, i will try to check this

regarding the belt tensioner, what is the difference between this one :
http://www.whiteracingproducts.com/i...products_id=91

and the one from ecklers
http://www.ecklerscorvette.com/corve...1988-1991.html

there is a huge difference of price between them

mike100 · 06-03-2013

Quote:

Originally Posted by DarkAngel

thanks for your answers, i will try to check this

regarding the belt tensioner, what is the difference between this one :
http://www.whiteracingproducts.com/i...products_id=91

and the one from ecklers
http://www.ecklerscorvette.com/corve...1988-1991.html

there is a huge difference of price between them

The cheap one does not fit the LT5. Marc Haibeck rebuilds the tensioner part if it doesn't turn out to just be the pulley bearing. i think it could also be a bad alternator bearing- removing the belt and hand spinng some of those accessories might tell you.

Dynomite · 06-03-2013

Just in case you want to try something different

Experimental Bling

geezer · 06-03-2013

Functionally no difference. If you isolate the problem to the tensioner pulley ( as per Scott fab suggestions) try Jerry's Gaskets for the best price on a OEM pulley.

Blue Flame Restorations · 06-03-2013

Dual mass??? Where is the noise coming from? Front or rear of engine?

DarkAngel · 06-04-2013

Quote:

Originally Posted by Blue Flame Restorations

Dual mass??? Where is the nokise coming from? Front or rear of engine?

it seems it comes from the front of the engine

rkreigh · 06-04-2013

sure sounds like the tensioner, and that pulley has a strange wobble to it too

probably the bearing is shot.

start the engine briefly without the belt

wiggle each pulley other thing that can happen is (rare) the chain guide can fail and make a racket - hope it's not that!!

06-02-2013	#1
DarkAngel Join Date: May 2013 Location: France Posts: 55	Unknown strange engine noise Hello, Ive made videos this week-end about a strange engine noise that i cannot identify It appears when the engine is running and also when it stop, it makes a metalic noise like "rattle" on the third video, we can hear it a little but usually it makes much more noise The belt tensioner does not seem to move excessively and ive checked that the alternator and climate pump is tight correctly If someone has an idea from where it can come from ... Thanks for your help 1) http://youtu.be/OpJT7LIqf9M 2) http://youtu.be/Mc3TUkZx-zA 3) http://youtu.be/QFJsKHduLTo Last edited by GOLDCYLON; 06-06-2013 at 11:52 AM.

06-03-2013	#2
geezer Join Date: Aug 2010 Location: ottawa canada Posts: 156	Re: Unknow strange engine noise Sounds like belt tensioner/ bearing. Easily available on the internet. IMHO

06-03-2013	#3
scottfab Join Date: Jan 2009 Location: Portland Oregon metro area (Washington side) Posts: 3,207	Re: Unknow strange engine noise 1. Remove the belt and inspect it for a bad spot. 2. Belt ok? then spin each, water pump, A/C, alternator, idler pulley and tensioner pulley as well as the PS pump. Listen and feel for any grinding. __________________ Scott Vett owner since 1979._It's about the car and the people

06-03-2013	#4
DarkAngel Join Date: May 2013 Location: France Posts: 55	Re: Unknow strange engine noise thanks for your answers, i will try to check this regarding the belt tensioner, what is the difference between this one : http://www.whiteracingproducts.com/i...products_id=91 and the one from ecklers http://www.ecklerscorvette.com/corve...1988-1991.html there is a huge difference of price between them

06-03-2013	#6
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,797	Re: Unknow strange engine noise Just in case you want to try something different Experimental Bling __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS

06-03-2013	#7
geezer Join Date: Aug 2010 Location: ottawa canada Posts: 156	Re: Unknow strange engine noise Functionally no difference. If you isolate the problem to the tensioner pulley ( as per Scott fab suggestions) try Jerry's Gaskets for the best price on a OEM pulley.

06-03-2013	#8
Blue Flame Restorations Join Date: Feb 2010 Location: Pendleton, IN Posts: 3,904	Re: Unknow strange engine noise Dual mass??? Where is the noise coming from? Front or rear of engine? __________________ 1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project Last edited by Blue Flame Restorations; 06-04-2013 at 10:20 AM.

06-04-2013	#10
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,087	Re: Unknow strange engine noise sure sounds like the tensioner, and that pulley has a strange wobble to it too probably the bearing is shot. start the engine briefly without the belt wiggle each pulley other thing that can happen is (rare) the chain guide can fail and make a racket - hope it's not that!! __________________ 95 390 LPE ZR1 (505 rwhp) LSV = Lingenfelter Super Vette Twin Turbo 2003 Z06 (800 RWHP)