Unknown engine noise help

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

S

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,737
Reaction score
11,290
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
The thing that makes this a little harder is your exhaust. What I mean is your exhaust on the video at least sounds pretty loud, which covers the noise considerably. I would have bet on water pump until you said it did it with the fan belt off. I'd say test it again when you have time. Remove the fan belt, test. Remove P/S belt test again. If the noise is still there try to isolate generally where it is coming from, as in front of the engine or back. Noises can travel in weird ways sometimes and this might require carefully getting under the engine or above it with engine running. This is NOT going to be coming from rod or main bearings. It really sounds like accessory noise, but if it's not something belt driven then I suppose it's possible it could be something from under the timing cover maybe possibly the oil pump. Let us know what you find when you do more work on isolating it.
 
78C10BigTen

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,575
Reaction score
23,966
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
SirRobyn0 said:
The thing that makes this a little harder is your exhaust. What I mean is your exhaust on the video at least sounds pretty loud, which covers the noise considerably. I would have bet on water pump until you said it did it with the fan belt off. I'd say test it again when you have time. Remove the fan belt, test. Remove P/S belt test again. If the noise is still there try to isolate generally where it is coming from, as in front of the engine or back. Noises can travel in weird ways sometimes and this might require carefully getting under the engine or above it with engine running. This is NOT going to be coming from rod or main bearings. It really sounds like accessory noise, but if it's not something belt driven then I suppose it's possible it could be something from under the timing cover maybe possibly the oil pump. Let us know what you find when you do more work on isolating it.
Click to expand...
Yes my exhaust is very loud, its headers and 3" pipe to flowmasters but i thought the video caught the noise very well. It does sound like the very front of the engine.
 
78C10BigTen

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,575
Reaction score
23,966
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
I have another short vid of the noise that i took right before i removed the belt but im not sure you can hear it
 
Scotty D

Scotty D

Member
Joined
Dec 5, 2019
Posts
43
Reaction score
41
Location
Convoy, Ohio
First Name
Scott
Truck Year
1979
Truck Model
C10 Bonanza Big10
Engine Size
305
How old is the timing chain?
Hopefully it’s not the chain rattling against the front cover, unfortunately I had that happen, wasn’t pretty.
 
78C10BigTen

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,575
Reaction score
23,966
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Scotty D said:
How old is the timing chain?
Hopefully it’s not the chain rattling against the front cover, unfortunately I had that happen, wasn’t pretty.
Click to expand...
Honestly i couldnt tell ya.... supposedly this motor came from a stock 76' (i believe) idr exactly, my gf found it on FB when my motor blew. I do remember the guy tellin me it came outta his grandpas stock truck when it rotted out.
 
bucket

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,087
Reaction score
23,893
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Scotty D said:
How old is the timing chain?
Hopefully it’s not the chain rattling against the front cover, unfortunately I had that happen, wasn’t pretty.
Click to expand...

It does sound like a chain type of noise. But I've never heard a small block or big block timing chain make noise.

Even this thing was silent right up until it failed:
You must be registered for see images attach
 
S

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,737
Reaction score
11,290
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
I can hear the noise in the video don't get me wrong, my only point was if you had happen to have a quiet single exhaust the noise would sound so much louder, there would be less exhaust noise interference and it would be easier to pick out subdued tones in the noise. I really can't image what in the front of the engine would a noise like that, other than the belt driven stuff. At the shop we'd remove the belts one by one, the only time I haven't found a noise like that by removing the belts has been on timing belt driven engines, obviously that's not the case here. Also I like to use a long section of heater hose for a listen device, of course be careful. And no I've never heard a chev V8 timing chain make noise, but there is always a first. Let us know what happens next.
 
Scotty D

Scotty D

Member
Joined
Dec 5, 2019
Posts
43
Reaction score
41
Location
Convoy, Ohio
First Name
Scott
Truck Year
1979
Truck Model
C10 Bonanza Big10
Engine Size
305
When my chain went, it started that morning on the way to work, went out for lunch and when I went to start it up is where it went boom! Literally, with a backfire and that was it, pulled it apart to find a toothless gear and the front cover ground up from the chain beating on it.
 
legopnuematic

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
1,728
Reaction score
3,721
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
Check the fuel pump, the one on my 76 the pin wasn't being retained int the casting and was causing a rattle/click. Pump was not very old either. It would stop sometimes, then start making noise again. One picture is of the bad pump, other is of a good one.
You must be registered for see images attach
You must be registered for see images attach


Sent from my Moto Z (2) using Tapatalk
 
7

79dentside

Full Access Member
Joined
Nov 20, 2019
Posts
369
Reaction score
383
Location
Kansas
First Name
Brandon
Truck Year
1979
Truck Model
GMC Sierra Classic
Engine Size
350
Any update on the noise? I would check the front accessories with a stethoscope first (being careful not to put it on anything moving of course).

This is not a Chevy in this video, BUT I had a TERRIBLE knock/and or whine depending on the day that would go away once it warmed up. It ended up on my car being an alternator. It was extremely loud and would go away completely.
xc_hide_links_from_guests_guests_error_hide_media

I thought I had severe engine issues/or timing chain tensioner leak down problems.... A stethoscope revealed my awful noise. Check the easiest things first!
 
78C10BigTen

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,575
Reaction score
23,966
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Ive isolated it past alternator by running it without the belt. It still makes it intermitently and i have not got time to go further into it.
 
7

79dentside

Full Access Member
Joined
Nov 20, 2019
Posts
369
Reaction score
383
Location
Kansas
First Name
Brandon
Truck Year
1979
Truck Model
GMC Sierra Classic
Engine Size
350
78C10BigTen said:
Ive isolated it past alternator by running it without the belt. It still makes it intermitently and i have not got time to go further into it.
Click to expand...

Them stethoscopes are great little tools, I love mine. Good luck finding it, I hope it’s nothing major.
 
78C10BigTen

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,575
Reaction score
23,966
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
79dentside said:
Them stethoscopes are great little tools, I love mine. Good luck finding it, I hope it’s nothing major.
Click to expand...
I also did try the long screwdriver to my ear trick but came up with nothin
 
78C10BigTen

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,575
Reaction score
23,966
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
I also took a good look at the pulleyes while it was runnin and they all seem good and square, no wiggle or nothing so cant be there either
 
You must log in or register to reply here.

Similar threads

Chuckd84
Fuel line knock/hammer/noise
Replies
4
Views
329
Chuckd84
Chuckd84
Timothy69420
help me find this ticking noise on my truck ( 1978 Chevy C10 305 )
Replies
13
Views
654
fast 99
fast 99
C
Engine noise
Replies
4
Views
428
TJ1978
T
PhotonFanatic
How to deal with that snoring noise?
Replies
4
Views
527
82sbshortbed
82sbshortbed
S
Engine / exhaust noise care to take a stab at what it might be?
Replies
4
Views
305
SirRobyn0
S

Latest posts

Forum statistics

Threads
42,070
Posts
908,368
Members
33,545
Latest member
GrayWK
Top