INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

Whirring noise...normal or an issue?

Thread Tools
 
Search this Thread
 
Old 09-28-2015, 12:37 AM
  #1  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
lukn4trbl355's Avatar
 
Join Date: Aug 2010
Location: Gurnee, IL
Posts: 741
Likes: 0
Received 1 Like on 1 Post
Default Whirring noise...normal or an issue?

Hey guys Ive recently had my 370 line honed for arp mains and bored .040 rebalance etc to fix it's previous builders issues. Piston to wall clearance is 5 thou after plateau hone new bearings rods and mains are now at .0022 and I set thrust at 5 thou. Oil pump was aligned properly as well as converyer to flexplate distance. Once I put my "sleeper" exhaust on I noticed the engine had a faint whirring noise coming from the pan which is more noticable when warm. With a screwdriver I listened and it seems to be coming from the front to center area. I had my machinist/old boss listen to it and he said it doesn't sound bad and is probably normal but thought it sounded more like my trans pump echoing through the alum pan. He isn't used to hearing an engine that's this quiet so it's kinda in the back of my mind. Oil filters all have been clean every oil change but I'm beyond **** with noises. Idk if it's from being a loose toleranced engine or the fact his old school machinist said the noise could be coming from the helical style gears in the oil pump or that im hearing the torrington bearing in my timing set. I just don't know if it's something I should worry about or if I should just stop worrying but its a 12k investment and I'm now flag broke lol. Also oil pressure is about 58 hot with 15w50 and 70-75 @wot.
Old 09-28-2015, 12:41 AM
  #2  
Mod with training wheels
iTrader: (16)
 
smokeshow's Avatar
 
Join Date: Feb 2009
Location: Detroit
Posts: 7,738
Received 202 Likes on 138 Posts
Default

How much run time/miles on the engine?
Old 09-28-2015, 12:45 AM
  #3  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
lukn4trbl355's Avatar
 
Join Date: Aug 2010
Location: Gurnee, IL
Posts: 741
Likes: 0
Received 1 Like on 1 Post
Default

I think 400 to 450ish
Old 09-28-2015, 12:57 AM
  #4  
Mod with training wheels
iTrader: (16)
 
smokeshow's Avatar
 
Join Date: Feb 2009
Location: Detroit
Posts: 7,738
Received 202 Likes on 138 Posts
Default

Could just be that you're hearing the rings on the cylinder bores. They're much louder before the engine is really broken in. They make a faint scrape noise when you crank an engine with a ratchet after assembly, which can sound like a whirr at running RPM.
Old 09-28-2015, 01:05 AM
  #5  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
lukn4trbl355's Avatar
 
Join Date: Aug 2010
Location: Gurnee, IL
Posts: 741
Likes: 0
Received 1 Like on 1 Post
Default

Hmm does make sense we ended up using stainless rings and I know that's a tough surface . I'm hoping I'm just over reacting and that it's something minor. It's probably got 15 hard pulls on it and runs flawless other than the low rpm bucking but it's a large cam with big time rotating mass. The only way I can describe it is just like a dull whine/whirr but what your saying does kinda make sense just don't know why it's louder in some areas ya know?
Old 09-28-2015, 10:28 PM
  #6  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
lukn4trbl355's Avatar
 
Join Date: Aug 2010
Location: Gurnee, IL
Posts: 741
Likes: 0
Received 1 Like on 1 Post
Default

Nobody else has similar issues or the same sound?
Old 10-03-2015, 10:34 AM
  #7  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
lukn4trbl355's Avatar
 
Join Date: Aug 2010
Location: Gurnee, IL
Posts: 741
Likes: 0
Received 1 Like on 1 Post
Default

Thinking about it as well do you guys think there's any chance the oil pump somehow could have shifted? I mean I can't think of anything else that would make that noise other than the pump/timing chain.
Old 10-21-2015, 11:19 PM
  #8  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
lukn4trbl355's Avatar
 
Join Date: Aug 2010
Location: Gurnee, IL
Posts: 741
Likes: 0
Received 1 Like on 1 Post
Default

I just thought about it. Harmonics could also cause a whine correct? I just noticed only at idle my asp ud junk has a slight wobble to it which with any increase in rpm goes away as well as the noise
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Idryfly5
GMT 900 Trucks General Discussion
2
09-02-2022 08:55 PM
murderedSS
Tuning, Diagnostics, Electronics, and Wiring
27
10-12-2015 11:13 AM
TAPyvehc93
GM Drivetrain & Suspension
4
09-14-2015 01:22 PM
dselby25
TOWING & OFFROAD PERFORMANCE
2
09-11-2015 05:03 AM
Boyes50
FUEL SYSTEMS
2
09-08-2015 12:06 PM



Quick Reply: Whirring noise...normal or an issue?



All times are GMT -5. The time now is 11:17 PM.