LOUD noise from engine
Thread Starter
Instructor
Joined: Sep 2005
Posts: 185
Likes: 0
From: Buckner Missouri
LOUD noise from engine
1974 with 350 engine.
I drove the car last weekend and parked it. All was fine when I parked it.
Went out this afternoon and started her up. A loud "chirping" noise came from the front of the engine at idle. As the idle speeds up the "chirping" changes to a metalic tapping.
Using a stethoscope I traced the sound down to just BEHIND the water pump. Place the stethoscope on the pump and all sounds fine. In the picture below where the green arrow is point behind the Pump is where the sound seems to be coming from.
I have never heard this type of sound from an engine before.
Very Loud and turning into a metalic tap as revs increase.
Listened to the fuel pump and all sounds fine there also.
Any guess?
Also what is inside that brown metal band behind the Pump?
I drove the car last weekend and parked it. All was fine when I parked it.
Went out this afternoon and started her up. A loud "chirping" noise came from the front of the engine at idle. As the idle speeds up the "chirping" changes to a metalic tapping.
Using a stethoscope I traced the sound down to just BEHIND the water pump. Place the stethoscope on the pump and all sounds fine. In the picture below where the green arrow is point behind the Pump is where the sound seems to be coming from.
I have never heard this type of sound from an engine before.
Very Loud and turning into a metalic tap as revs increase.
Listened to the fuel pump and all sounds fine there also.
Any guess?
Also what is inside that brown metal band behind the Pump?
Burning Brakes
Joined: May 2005
Posts: 1,145
Likes: 5
From: South of London, Engerland
That 'brown' metal band is the top of the timing chain cover. Behind the cover is ...err... the timing chain. 
If you're getting metalling rattling/scraping from that area then I'd say it'd be worth taking off the timing chain cover and checking you haven't lost a link pin or plate. It's pretty easy to do, but you'll need to drain down the coolant and buy new water pump and timing chain cover gaskets in preparation (plus some sealant).
You don't want to risk the timing chain failing...
If you're getting metalling rattling/scraping from that area then I'd say it'd be worth taking off the timing chain cover and checking you haven't lost a link pin or plate. It's pretty easy to do, but you'll need to drain down the coolant and buy new water pump and timing chain cover gaskets in preparation (plus some sealant).
You don't want to risk the timing chain failing...
Burning Brakes
Joined: May 2005
Posts: 1,145
Likes: 5
From: South of London, Engerland
Thought of another thing: before you remove the water pump but after you've removed the belts, check for play in the water pump shaft. The chirping sound could be your pump bearings, but if you're getting no coolant leakage from the pump then it won't be too bad yet.
Pumps can make some weird noises as they fail.
If there's no looseness in the water pump then I'd continue stripping off the timing chain cover.
Pumps can make some weird noises as they fail.
If there's no looseness in the water pump then I'd continue stripping off the timing chain cover.
Drifting
Joined: Mar 2005
Posts: 1,806
Likes: 3
From: Burlington WI
Originally Posted by BenUK
Thought of another thing: before you remove the water pump but after you've removed the belts, check for play in the water pump shaft. The chirping sound could be your pump bearings, but if you're getting no coolant leakage from the pump then it won't be too bad yet.
Pumps can make some weird noises as they fail.
If there's no looseness in the water pump then I'd continue stripping off the timing chain cover.
Pumps can make some weird noises as they fail.
If there's no looseness in the water pump then I'd continue stripping off the timing chain cover.
They can make noise and not leak.
Chris B
Thread Starter
Instructor
Joined: Sep 2005
Posts: 185
Likes: 0
From: Buckner Missouri
Originally Posted by BenUK
That 'brown' metal band is the top of the timing chain cover. Behind the cover is ...err... the timing chain. :
:25 years ago I knew that. Guess I'm gonna get the chance to know it again.
Thanks for not making me feel like a COMPLETE fool. :>)
I did like the chuckle I got from your explaining what was behind the cover.
OK, gotta start taking her apart this weekend. I know it will take awhile since I'm booked for Saturday and we all know what Sunday is.
I'll hope it's the watter pump and won't be supprised if it isn't.
Dang, first nice weekend weather-wise in quite awhile. Sorta wanted to take her, uh, the 'Vette (and the wife) to dinner tonight.
Thanks Ben and Chris for the info.
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Before taking anything apart, I would suspect a warped pully or
dry belt. If you don't have any belt dressing, try a spray bottle
of water and spray the belt/pulley to hear if the sound disappears
or changes. If so, try a new belt first ... easy and not expensive.
dry belt. If you don't have any belt dressing, try a spray bottle
of water and spray the belt/pulley to hear if the sound disappears
or changes. If so, try a new belt first ... easy and not expensive.
Burning Brakes
Joined: May 2005
Posts: 1,145
Likes: 5
From: South of London, Engerland
Originally Posted by Blue 74
Thanks for not making me feel like a COMPLETE fool. :>)
I did like the chuckle I got from your explaining what was behind the cover.
I did like the chuckle I got from your explaining what was behind the cover.
Good luck with it.
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Burning Brakes
Joined: Sep 2005
Posts: 1,078
Likes: 0
From: Santee CA
Good luck with that...
My '74 with the 350 engine is doing the same thing. However, mine's not the water pump, it's something to do with the valvetrain, as the noise is coming from back by the #6-#8 cylinders on the passenger side.
Hopefully it's just a bad water pump, in your case...I know with my '67 Jaguar, we just replaced the water pump because the bearings had gone on it and was causing the impeller shift and hit the sides of the casing. We kept hearing this pinging noise that got worse as we'd rev it, and it was because the tension on the serpentine belt was pulling the water pump pulley off kilter. Made a similar noise, came from the front of the engine, as you're describing.
If it's that, it'll be a lot cheaper than doing a full rebuild, as the worst case scenario is that you have to go buy a new water pump.
My '74 with the 350 engine is doing the same thing. However, mine's not the water pump, it's something to do with the valvetrain, as the noise is coming from back by the #6-#8 cylinders on the passenger side.
Hopefully it's just a bad water pump, in your case...I know with my '67 Jaguar, we just replaced the water pump because the bearings had gone on it and was causing the impeller shift and hit the sides of the casing. We kept hearing this pinging noise that got worse as we'd rev it, and it was because the tension on the serpentine belt was pulling the water pump pulley off kilter. Made a similar noise, came from the front of the engine, as you're describing.
If it's that, it'll be a lot cheaper than doing a full rebuild, as the worst case scenario is that you have to go buy a new water pump.
Thread Starter
Instructor
Joined: Sep 2005
Posts: 185
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From: Buckner Missouri
Originally Posted by standup
It looks wet behind the timing cover.....somethings leaking ?????
Thread Starter
Instructor
Joined: Sep 2005
Posts: 185
Likes: 0
From: Buckner Missouri
Originally Posted by Sprzout
Good luck with that...
....... Made a similar noise, came from the front of the engine, as you're describing.
If it's that, it'll be a lot cheaper than doing a full rebuild, as the worst case scenario is that you have to go buy a new water pump.
....... Made a similar noise, came from the front of the engine, as you're describing.
If it's that, it'll be a lot cheaper than doing a full rebuild, as the worst case scenario is that you have to go buy a new water pump.
Thanks for the positive thoughts.
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Many, many years ago I had a 350 that made a similiar noise. I was fairly certain that it was coming from the timing chaning cover. The noise was not there before and then all of a sudden it was there. A day or two later it was gone and never came back.
Safety Car
Joined: Oct 2000
Posts: 3,547
Likes: 12
From: Carbondale Pa.
Good luck to you and for your sake I do hope it is the water pump because if it isnt you are in for a mini-struggle in getting the timing cover off and a slightly bigger one in getting it back on, you have to loosen the oil pan most times and also snip the upper edges of the timing cover where the pan to cover seal rubber sits (to get it back on), also if it is a loose chain or worn timing gears be sure to line up the marks on your timing gears before you take them off ,,,Peace,,,Moosie
P.S. Might it be a balancer thats starting to slip with it hitting the cover sometimes? you'd be able to see it wobble when the motor is running
P.S. Might it be a balancer thats starting to slip with it hitting the cover sometimes? you'd be able to see it wobble when the motor is running
Last edited by moosie982; May 13, 2006 at 09:24 AM.
