SOLVED! Engine Bay Noises - Water Pump, bearings, lifters?

Blckshdw

Original poster
Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Alright, like I said in the chat thread, I think I'm just being paranoid, but since I got the trans replaced, I'm hearing all sorts of random, inconsistent, noises that worry me. For a while now, I've suspected my water pump might be on its way out, but my temps have stayed in acceptable ranges, and any noise hasn't been too alarming. A couple days ago, I thought I heard the characteristic rock in a tin can noise on a cold startup before work. When I got home, and made a recording, the noise was nearly gone. Only heard the clank a couple of times within a few minutes.

This morning, there was a loud and repeated knocking noise. Increased with RPMs, but it drove to work fine, and seemed to settle down after a few minutes. During my research, came across a number of threads and videos, among them was this video, cuz this is the same sound I heard (just a lot faster)


So that had me a bit nervous. Also saw that many suggested removing the belt, and seeing if any noises went away. But of course, when I started the truck to come home, the noise was gone. Shot some video anyway, stopped and removed the belt for a bit, and then spun the accessories by hand. When the belt was removed, there's a ticking sound that seems to be coming from the top of the engine. Is this the famed lifter tick that I've heard about? After tinkering with the fan, I'm pretty confident that it's time to order a new water pump.

Does anyone hear anything with their trained ears, that I should be mindful of?

 
Solution
I just had another thought about what the additional dynamics might be that could have contributed to a Water Pump Bearing Failure. IIANM... There can be small thin "Wheel Weights" that can be attached to the Fins of the Fan Blades at the GM Factory in order to achieve the affect of "Balancing The Wheel" ...so to speak.

It occurred to me that if any of those 'weights' came off of the Fan Blades or were intentionally removed... the resulting "out of balance" condition could put an additional axial strain on the Water Pump Bearings and presage an Early Failure of the OEM Water Pump. If nothing else... it will be worth checking to see if there are any 'clean spots' where such weights may have accidentally fallen off.

Blckshdw

Original poster
Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Also, oil level is normal, last oil change was in December. From what was on the dipstick, didn't see anything glitter-like.
 

mrrsm

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Oct 22, 2015
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I think you can rule out having any Bad Main Crankshaft Bearings... with NO sounds of any Rod Knock at Idle. Because of the careful Dynamic and Static diagnosis you performed... I'm +1 for Bad Water Pump Bearings because of the presence of Bearing Growl in the Water Pump Cavity when the Engine was Running at idle... its obvious absence when the Serpentine Belt was removed... and then the rattling sounds the Water Pump Bearings made when you were hand-spinning the Fan Assembly with the engine turned off. @Matt 's Water Pump R&R Thread is The BEST " How To R&R" for this repair...Ever.

You should be able to Breathe now, Carlton... :>)

 
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Mooseman

Moderator
Dec 4, 2011
25,258
Ottawa, ON
Since ot seems to be coincidental to the tranny R&R, maybe give the flex plate bolts a check.
 

Mooseman

Moderator
Dec 4, 2011
25,258
Ottawa, ON
Dis you try running it with the belt off? that would certainly eliminate anything with the engine itself.
 

Blckshdw

Original poster
Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Dis you try running it with the belt off? that would certainly eliminate anything with the engine itself.

Yeah, took the belt off right around the minute mark in my video. I'm sure the phone mic doesn't pick things up as well as a live ear, but it was a lot quieter.

Also use some sort of stethoscope or even a solid rod to pin point where the sound is emanating from.

With the belt off, the only sound I was unsure about, was a rapid ticking sound, seemed like it was coming from the top end. But it may be normal, or my imagination, since no one else mentioned it.


Went to look at water pumps on Amazon, and turns out I have 2 AC Delco units in my truck parts wish list. I can't tell the difference between the 2 other than model number and price. Leaning towards the OEM one, just because it's OEM. Anyone have any other recommendations to consider?

ACDelco 252-822 Professional Water Pump Kit for $40

ACDelco 251-731 GM Original Equipment Water Pump for $88
 

xavierny25

Member
Mar 16, 2014
6,323
Staten Island, N.Y
Have you tried removing the brake booster line and plugging it with your finger to see if that ticking sound goes away? I know this test doesn't confirm anything other then you might have a bad booster check valve(or whatever its called).

I replaced mine a while back(3yrs ago I think) when I had a ticking noice and it actually worked on removing that noice. I still get a slight tick ever once in a blue but only when I have the ac cut in and out and honestly it will tick for 3-4 seconds stop and then repeat 10-15 minutes later. I drive with the auto hvac set to 68f-70f, colder when the inside of the truck is hot as f#ck.

I grabbed the 40 dollar pump last time and it's working just fine for me.
 

Blckshdw

Original poster
Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Have you tried removing the brake booster line and plugging it with your finger to see if that ticking sound goes away? I know this test doesn't confirm anything other then you might have a bad booster check valve(or whatever its called).

Doing this hadn't even crossed my mind. It will be worth a shot, although I'll have no idea what it means if the ticking doesn't go away :bonk: I was only able to hear it, when the belt was off, and nothing else was running besides the engine.
 

Mooseman

Moderator
Dec 4, 2011
25,258
Ottawa, ON
They're probably the same pump. Just marketing saying it's a GM OEM part. I think you're on the right track with the pump.
 

Blckshdw

Original poster
Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Was halfway through the neighborhood on the way to the grocery store, when the water pump got consistently noisy, and quite loud compared to all week prior. Considerable vibrations with any application of throttle, so I babied it there and back. Also accompanied by a nice burning smell of some kind. As you can see there's a lot more play in the fan, than there was a couple days ago.


Luckily for me, while I was out, Amazon delivered the new pump, and I still have a couple jugs of Dexcool since I bought too much when I swapped out my T-stat last winter. Would have been nice if it was still morning, and nice and cool out. Parked head-in, and have a fan to try and cool down the engine bay. I'll use my air chisel to spin off the fan clutch nut. Time to sink or swim!!

20190428_142132.jpg
 

Mounce

Member
Mar 29, 2014
13,667
Tuscaloosa, AL
Possibly coolant drizzling out and burning or worse the fan touching the shroud or something. Also I never thought about it but I bet that's rough on the clutch wiring once it gets that loose.
 

mrrsm

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Oct 22, 2015
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Even though the outside surface of the Water Pump Serpentine Pulley is Smooth and Un-Grooved... the radical, wobbly motion of the Fan at its outer edges can tilt that pulley rapidly back and forth... acting like a Kid coming to a Skidding Stop with New Sneakers on a Linoleum Floor. This action can make enough additional sideways friction to wear in and Heat Up the Non-Ribbed side of the belt; possibly enough to make it melt, if the Serpentine Belt gets pulled tight enough against it in that area. Perhaps a better example would be like holding your palms tightly together while rubbing them rapidly back and forth ... it does not take very much of that action to make them soon become ...unbearably hot.
 
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Blckshdw

Original poster
Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
@MRRSM it did smell more like a melting rubber, than melting plastic type of smell, so that makes sense. And the fan was definitely a lot more wobbly than a few days ago. Got everything buttoned up, and let it run up to temp to burp the cooling system. No leaks, and most of all, a much quieter running truck.


Now just need to clean up the garage floor...
 

mrrsm

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Oct 22, 2015
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I just had another thought about what the additional dynamics might be that could have contributed to a Water Pump Bearing Failure. IIANM... There can be small thin "Wheel Weights" that can be attached to the Fins of the Fan Blades at the GM Factory in order to achieve the affect of "Balancing The Wheel" ...so to speak.

It occurred to me that if any of those 'weights' came off of the Fan Blades or were intentionally removed... the resulting "out of balance" condition could put an additional axial strain on the Water Pump Bearings and presage an Early Failure of the OEM Water Pump. If nothing else... it will be worth checking to see if there are any 'clean spots' where such weights may have accidentally fallen off.
 
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