Whining Noise
 

Changed my oil cooler lines, everything works fine exept for a whining noise my car makes, almost like the entire engine noise has changed. People who have never heard a rx8 engine would not notice it as being abnormal. Its like a whine/buzz that increases in pitch and volume as rpms increase, kind of like a super charger but with the pitch and volume thing. I would be lieing if i said i didnt like it, it sounds like alien technology :mdrmed:. I didnt ask about it earlier because i thought for sure it was just like a zip tie rubbing on one of the pullies, or the airbox. However after almost three days, I am unable to locate what or wear the noise is coming from. During the oil cooler line change I removed the battery and box, airbox, and oil lines... nothing else was touched, besides the electrial connecter behind the pully so i could pump oil back into the coolers without starting the engine. Could any of that cause a change in engine sound? The car runs same as before, starts in less than a second, idles with no vibration, no power loss, oil pressure (stock gauge) is the same, and temp is not high.

** I would like to stress how normal it sounds. It is less like a whine, and more like an completly new engine nosie. The motor and the new pitch go hand in hand.

EDIT_ UPLOADED A SOUND CLIP

any chance you are using the aux input like for a ipod or anything

Nah, I am familiar with alternator whine, its not as high pitched, and again... its not really a noise that is seprete from the engine noise. It is more like the tone of my motor has changed when i replaced the lines. What i am asking is, could new oil lines cause a change in engine tone, or is it something that i have not assembled correctly and neglected to tie down. I have looked at a few sound clips recently of the series 2 rx8s, my engine rev sounds alot more like one of the newer cars... which is leading me to consider the possibility that increased oil flow is causing the new tone, and perhapes my old lines where somehow restrictive, but at the same time i also feel as if this were true, then my oil pressure on the stock guage would be differnt and it isnt. I am unsure if i should get it checked out or accept the slightly altered tone. I wish i had a before and after sound clip... unfortunatly i do not.

Still sounds like a bad battery connection where you will hear the whine through your speakers.

Otherwise there is a motor for pollution on start up. Those are known to go bad. Maybe that is stuck on.

You can unplug it. To check look On passenger side

Also, water pump belt can whine too.

Go to club meet. Sounds are hard to ID over Net your whine is a clunk to me.

Everyone describes thing differently.

interesting. A good way to describe my noise is like when you have power steering maxed out and it makes that buzz type sound. A pump going bad would make sense. Its coming from around the upper intake manifold. I took a long screw driver and held it against a few parts of the motor and listend to it at idle. It is deffiently the loudest around the upper intake area. Is that where this pollution pump is located?

upper intake manifold is on passenger side.... And how important is this motor for pollution.. if its not needed for engine function then by all means screw then environment

Got a sound clip, hopefully its noticable in the video!

Sounds like something is in the intake.

should let the hooker out of the trunk.... just sayin :dunno:

First off.......quit looking at the oil gauge in the car.................it's basically a dummy gauge.
I don't think it's the air pump(what someone above mentioned and is for emissions).
Think I would take the intake track apart and give it a look. You didn't "f" up one of the screens did you?
I'm assuming you had to take the accordion out and stuff to get to the oil cooler lines.

I checked the airbox but havnt checked the plastic manifold. Ill have to take a look tommarow morning. Thank you all for the feedback... there was not a hooker in my trunk at the time zoom

I'd hate to bring up a a new comment but...
 

Did you ever figure out what it was? I just did and oil change and a new oil filter and it now has that alien buzz that sounds sooooo nice but it's kinda scary since I've never heard it before and I've had the car about 4 months and I just did my first oil change on it??

Thread necromancy!

I seem to be having the same problem as the OP, and, oddly enough, after building and replacing all of my oil lines, just as he described as well. I'm not sure what to make of it, but the description he provided is spot on.

he said the noise was loudest near the UIM in post #5

can you confirm?

admit it, you love to play “doctor” :suspect:


https://cimg0.ibsrv.net/gimg/www.rx8...ec38773f6.jpeg
.


did you replace them with aftermarket lines?
.

I don't think it's coming from the UIM like the OP stated, so that part may be different.

I think it's coming from the one of the if not both of the bottom oil lines, one of them goes to the front cover, the other goes right underneath the oil filter pedestal. It would appear to me there is some resonance happening. Looking at the OEM oil cooler set up, they are about half rubber and half metal, with lots of insulators. These are just Fragola fittings I made with PTFE line, but there is no sound insulator, it goes from metal fitting, to a metal external thermostat that's metal on metal mounted, to a metal oil cooler with no real cushion in between. I've also noticed the sound is worse when the hood is closed, it's definitely resonating through the body. I swapped out the alternator with a spare I had on hand, with no change. After swapping the alternator there isn't much left to test besides the water pump, but that was replaced with the new engine. I pulled the AC belt and ran it to make sure it wasn't the idler or compressor and there was no change there either.

And after doing some more specific searching, I came across this: https://www.rx8club.com/series-i-tro...-lines-221936/

I don't know if the guy in this post put on aftermarket lines or OEM ones, but now I appear to be the 3rd person to report a similar noise problem on this forum, after changing the oil lines. EDIT: Actually, he was using the racing beat oil lines, according to comments on his YT video.

The only reason I can think of that this sound wasn't happening before with the original redhorse rubber lines that came with the kit is that the rubber lines do insulate somewhat, the PTFE inner lining is super thin and doesn't seem like it would be as good of an insulator as rubber, and it's certainly not as thick. I can feel the vibration in the line that matches the sound. That's my theory, anyway. It makes sense in my head, not sure if it does in the real world. But common sense would dictate that if the car wasn't having a problem, and then you changed something, and now it is having the problem, it's something you messed with.

I think I need to find a way to insulate these stainless lines that are coming straight off the engine somehow, maybe some insulating rubber clamps or something similar. I tried to take a video of it, but it's hard to capture. It just sounds like if you have solid motor mounts and the frequency increases exactly with RPM.

go buy neoprene hot water pipe insulation at Home Depot et al and some temperature resistant tie wraps …
.

Okay, figured I'd post my solution in case anyone else came across this problem:

https://cimg7.ibsrv.net/gimg/www.rx8...bd9aaf0df8.jpg
https://cimg8.ibsrv.net/gimg/www.rx8...66bdf1c3b2.jpg


I ordered some neoprene and as suggested above, wrapped and zip tied the lines, taking care to insulate any part of the lines that would come into contact with the frame of the car. It's not my best work and looks kind of hackish, the proper way to do it would be to take the lines off the car entirely and insulate them on a bench, but I did not. The sound is still mildly present, I would imagine with a more thorough job it could be eliminated entirely, but it is tolerable now and I am willing to accept it as is. And I see yet again replacing the lines with a better product in the future, so when that time comes I will do it properly.

The gas pedal isn't vibrating and it doesn't sound like I have a supercharger. Mazda went through a lot of trouble engineering a solution to reduce NVH and resonance through the oil lines, just throwing some steel braided ones on there will change the sound a lot. I'm of the personal opinion that unless you need to change your oil lines for a specific reason, don't, or just install new or refurbished OEM ones. This one goes in the same category of cold air intake bin, sure you can replace it with something aftermarket and it will look cool, but it will be objectively worse than OEM.