Getting some whine with my cooler

[DRC]

Not sure if this is the best place to post this question but since it’s about a 4th gen, I will give it a try…

Okay, now this is starting to bug me a bit. About 3 weeks back I finally got around to installing an engine oil cooler. I am using a Glowshift sandwich adapter at the oil filter and have AN-10 lines running to my cooler core. Anyway, at this same time I started noticing a whining sound coming from my engine. Prior to installing the cooler I never noticed this whine but it is possible that it could have started sometime over this past winter before I installed the cooler and I am just hearing it now since it’s starting to warm up and I have had the windows down, etc.

I have a 08 v6 with 33,000 miles on it and the whine is more like a whirring sound. It sounds like I have a blower. Whish I did. The sound is very noticeable between 5mph and 40mph and most noticeable during deceleration in this speed range. When I am coming to a stop, after removing my foot from the gas, you really hear the whine. You know how when you take your foot off the gas and the RPM’s drop down then kick up a little bit around 1,000rpm, this is where the whine really can be noticed. My 12 year old son keeps asking me what’s wrong with my car? Once I come to a stop the whine starts to fade away slowly while idling. Also, the whine can be heard if I am in park or natural and hold the engine stead at about 2,000rpm’s so it’s not coming from the tranny.

I have found some other posts on the board about 4runners making a similar whine but these seemed to be related to a faulty belt tensioner, worn serpentine belt, bad alternator and a few unknown reasons. I have inspected all of these and everything seems to be in good working order. I can’t seem to find where the whine is coming from. I have had my head under the hood while the wife held the engine at 2,000rpm’s and I could hear the sound but could not find the source. It almost sounded like the noise was coming from the oil cooler lines. Is this possible? Can the sound of oil pumping through the lines / cooler make this kinda sound? Is this just a common 4runner sound that I am just noticing now and should not worry about?

Any advise / suggestions?

 

[Pegleg]

Not saying that it is the trouble, but yes, a line under enough suction to collapse it or even partially occlude it will most certainly cause a whine. There shouldn't be that much pressure in the system, however, unless those lines are really low grade garbage. If THAT is the case you'll soon have bigger issues than an annoying whine.

 

[DRC]

Thanks for the suggestion on the oil lines. I am running Russell Proflex braided stainless lines in AN-10 so the I.D is about 5/8” which makes the passage nice and wide. I think Russell makes a quality line or at least that is what others say. These lines are rigid as heck so I am not getting any collapse or fluctuation in the line. I am using AN high flow swivel fittings at the ends and I made sure when I installed the ends that I had no flap or anything like that. I don’t think the lines themselves are the cause of the whine but then again I have never worked with braided lines nor have I had an oil cooler so I have no frame of reference.

I don’t really know when the whine started. I am about 98% sure it started when the oil cooler went in as I am really anal about noise and I am sure I would have noticed this before but I can’t say for sure. I keep wondering if it’s the oil pump itself making the whine. I really don’t know much about oil pumps. Can an oil pump whine? Could the pump be overworked trying to push oil through the cooler?