Help troubleshooting an engine whine

[Berty_K]

Here's a video recording sound from the 4 corners of my engine bay (Front driver, rear driver, front pass, rear pass). https://youtu.be/c19-39yFcpM

If I start the car (hot or cold), there is no whine. The whine only starts once I get the engine past 2k, and does not go away after. The whine is then constant, even at idle.

I initially thought the whine was coming from the alternator or powersteering pump, but when I check both with an engine stethoscope, I didn't hear anything out of the ordinary.

The alternator is OEM. Power steering fluid is topped off (pump is oem). 3 idlers and 1 tensioner are less than a year old.

Thanks in advance for any guidance.

 

[Berty_K]

You can here the whine about 8 seconds into the video.

 

[DZNUTS]

The noise is at its loudest at about 18 seconds in. If there are any vacuum lines over there, spare them with a soapy water mixture and look for leaks. Does the pitch change with rpm? Does it change when applying the brakes?


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[Berty_K]

The noise is at its loudest at about 18 seconds in. If there are any vacuum lines over there, spare them with a soapy water mixture and look for leaks. Does the pitch change with rpm? Does it change when applying the brakes?


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Great idea. I'll give the soapy water mix a shot tomorrow.

Pitch drops slightly as RPMs go up.

Haven't tried the brake theory, but will try tomorrow.

 

[AuSeeker]

If you apply soapy water to any vacuum lines you will not get bubbles, it will be sucked into the engine, a mistake IMHO!!

 

[Berty_K]

If you apply soapy water to any vacuum lines you will not get bubbles, it will be sucked into the engine, a mistake IMHO!!

Do you have a better way to test for leaks?

 

[AuSeeker]

Do you have a better way to test for leaks?

https://www.google.com/search?q=aut....69i57j0l2.12102j0j7&sourceid=chrome&ie=UTF-8

 

[Berty_K]

Sound seems to be coming from the engine block itself. Checked with a stethoscope and its loudest by the middle coil. Any ideas?

 

[Berty_K]

This is awfully close to what I'm hearing https://youtu.be/gH0ztn1QzMQ

 

[Seymore Butts]

Put the stethoscope near the timing chain. I had a Nissan Pathfinder with defective timing chain tensioners and it sounded like that. However, not nearly as loud as that last video you posted.

 

[Berty_K]

Put the stethoscope near the timing chain. I had a Nissan Pathfinder with defective timing chain tensioners and it sounded like that. However, not nearly as loud as that last video you posted.

Yikes. Hoping it's not a timing chain.

Noticed my mechanic used a smaller oil filter. I'm gonna play it safe and change out my oil with a larger filter. I'm hoping its it's some thing like a clogged oil filter.

 

[DZNUTS]

The idea with the soapy water in a spray bottle is that if you find a leak, the engine RPM will dip for a split second.

You aren’t going to do any harm to your engine with the few drops worth of soapy water you’d be introducing to it


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[Berty_K]

For posterity sake... it was the oil filter.

I normally do oil changes myself, but was in a pinch and had him do it for me. He used a filter similar in size to the 90915-YZZD1.

Put in fresh oil and a bigger filter and the car is back to humming happily.

I'm guessing the sound was the oil pump straining from a clogged filter.

 

[Seymore Butts]

A clogged filter would cause its internal bypass valve to open, preventing any additional strain on your oil pump.

 

[Berty_K]

A clogged filter would cause its internal bypass valve to open, preventing any additional strain on your oil pump.

Any idea why I was getting the noise then?

 

[AuSeeker]

A clogged filter would cause its internal bypass valve to open, preventing any additional strain on your oil pump.

Any idea why I was getting the noise then?

What brand filter was on it when you were having the issue and did you use the same brand, type and weight oil to resolve the issue as what was in it?

But my best guess is the bypass/filter was defective, or the oil itself could be a factor.

The bypass in a oil filter opens more often then most would think, when the engine is cold the oil is thicker and may have trouble passing through the filter medium and thusly the bypass opens, also under hard acceleration the oil pressure jumps quickly and the bypass will open until the oil pressure equalizes in the filter, the bypass pressure level is usually between 5 and 20 PSI between the 2 sides of the filter medium, if you think about it the oil really doesn't need to be filtered all the time so the bypass is opened anytime the PSI gets high enough to open the bypass which is more often then you think if you watch the oil pressure, if the bypass is stuck closed or sticks from time to time even if the filter is not clogged the engine will be straving for oil at times.