L98 engine squeaking noise
Thread Starter
Advanced
Joined: Sep 2014
Posts: 59
Likes: 3
From: Berlin
L98 engine squeaking noise
Hi guys,
my L98 engine has a squeaking noise shortly after starting the engine.
Please see this video - I hope the sound can give a little impression of the noise: http://www.myvideo.de/watch/9793138
(you can hear it best from ~1:00 min on)
As far as I can say it does not come from the belt or a tensioner. But it is hard to say. It seems to me that it comes somewhere under the plenum or the ignition distributor. But this may deceive.
Does anyone have an idea where the noise may come from or how I can identify it best?
Thanks so much!
Mike
my L98 engine has a squeaking noise shortly after starting the engine.
Please see this video - I hope the sound can give a little impression of the noise: http://www.myvideo.de/watch/9793138
(you can hear it best from ~1:00 min on)
As far as I can say it does not come from the belt or a tensioner. But it is hard to say. It seems to me that it comes somewhere under the plenum or the ignition distributor. But this may deceive.
Does anyone have an idea where the noise may come from or how I can identify it best?
Thanks so much!
Mike
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
First off...it seems like the idle is quite high. What is the engine idling at??? Just curious.
I hear a noise...but I would say...when the noise is there. Shut off the engine and then re-start it to make sure it is still there.....then shut off the engine and remove the serpentine belt and then crank the engine again and see if it is still there. IF it is...shut off the engine and re-install the serpentine belt.
Then...start the engine again....and I have a stethoscope and listen with the tube for the noise. If you do not have a stethoscope...you can use a section of rubber hose/tubing and put it to your ear CAREFULLY and begin putting the other open end in the engine area until you can find it.
DUB
I hear a noise...but I would say...when the noise is there. Shut off the engine and then re-start it to make sure it is still there.....then shut off the engine and remove the serpentine belt and then crank the engine again and see if it is still there. IF it is...shut off the engine and re-install the serpentine belt.
Then...start the engine again....and I have a stethoscope and listen with the tube for the noise. If you do not have a stethoscope...you can use a section of rubber hose/tubing and put it to your ear CAREFULLY and begin putting the other open end in the engine area until you can find it.
DUB
Instructor
Joined: Sep 2005
Posts: 135
Likes: 12
Looks just like my '89 stock auto coup.
The squealing does sound similar to my engine, mine is like a little bird chirping when idling.
I was hoping that would go away on mine after I just did a bunch of work - but today was the first day I got my car running and that squealing is still there. The (rotating) items I can rule out, at least on my car is:
engine (just put a new ZZ4 short block on)
tensioner assembly (new)
power steering pump (new)
oil pump (new)
water pump (new)
timing chain (new)
only things that I didn't change out that rotate is the air pump (original) and alternator (relatively new). I think that's about everything that rotates.
It seems like the sound comes from below the engine somewhere like yours. I just got mine running and I'll be checking with my stethoscope and with and without serp belt on.
Let us know if you find anything - sure would be helpful for some of us. Hopefully someone will identify this noise.
I'll post back when I can check mine out shortly.
The squealing does sound similar to my engine, mine is like a little bird chirping when idling.
I was hoping that would go away on mine after I just did a bunch of work - but today was the first day I got my car running and that squealing is still there. The (rotating) items I can rule out, at least on my car is:
engine (just put a new ZZ4 short block on)
tensioner assembly (new)
power steering pump (new)
oil pump (new)
water pump (new)
timing chain (new)
only things that I didn't change out that rotate is the air pump (original) and alternator (relatively new). I think that's about everything that rotates.
It seems like the sound comes from below the engine somewhere like yours. I just got mine running and I'll be checking with my stethoscope and with and without serp belt on.
Let us know if you find anything - sure would be helpful for some of us. Hopefully someone will identify this noise.
I'll post back when I can check mine out shortly.
Thread Starter
Advanced
Joined: Sep 2014
Posts: 59
Likes: 3
From: Berlin
Ok thank you guys. So you mean I should take off or losen the belt and then start up the engine? Sounds like a good idea to if it is the cause of the noise.
And running the engine without the belt does NOT do any damage?
@DUB: about the idling rpm I can tell you tomorrow. I have a look.
And running the engine without the belt does NOT do any damage?
@DUB: about the idling rpm I can tell you tomorrow. I have a look.
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
The AIR pump and tensioner are two places I would look. As far as running the engine without the belt, no, it wont hurt anything but only run it for a little bit as you have no water circulating or recharge going to the battery. As stated if it doesnt squeak cut it off and put the belt back on. Well, spin each accessory and see if you feel any roughness first.
Race Director
Joined: Apr 2002
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From: Anaheim CA
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Joined: Apr 2009
Posts: 19,294
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From: Charlotte NC
It does not matter when you do this. IF the engine is HOT and the noise is there....take the belt off and crank it and see if the noise goes away. I am NOT saying drive for hours...ALL you are doing is seeing if the noise went away...when you knew it was there 30 seconds ago when the belt was on the engine.
All you need to do is rotate the belt tensioner and remove the belt completely.
DUB
All you need to do is rotate the belt tensioner and remove the belt completely.
DUB
Thread Starter
Advanced
Joined: Sep 2014
Posts: 59
Likes: 3
From: Berlin
Ok today I removed the belt and found the air pump squeaking when turning it -> http://www.myvideo.de/watch/9795326/c4
Everything else seems to be ok.
So I guess it's coming from the pump. Do I get this fixed without installing a new pump?
Everything else seems to be ok.
So I guess it's coming from the pump. Do I get this fixed without installing a new pump?
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
Just be careful when you separate it. Sometimes that can be very hard to do and you can break the housing due to build-up inside. Could be the vanes also...I have seen this before on some cars when I opened them up.
DUB
DUB
1st Gear
Joined: Jul 2019
Posts: 1
Likes: 0
Zz4 squealing just went through this with mine plastic plug passenger side valve to
Hi guys,
my L98 engine has a squeaking noise shortly after starting the engine.
Please see this video - I hope the sound can give a little impression of the noise: http://www.myvideo.de/watch/9793138
(you can hear it best from ~1:00 min on)
As far as I can say it does not come from the belt or a tensioner. But it is hard to say. It seems to me that it comes somewhere under the plenum or the ignition distributor. But this may deceive.
Does anyone have an idea where the noise may come from or how I can identify it best?
Thanks so much!
Mike
my L98 engine has a squeaking noise shortly after starting the engine.
Please see this video - I hope the sound can give a little impression of the noise: http://www.myvideo.de/watch/9793138
(you can hear it best from ~1:00 min on)
As far as I can say it does not come from the belt or a tensioner. But it is hard to say. It seems to me that it comes somewhere under the plenum or the ignition distributor. But this may deceive.
Does anyone have an idea where the noise may come from or how I can identify it best?
Thanks so much!
Mike