Engine whine - oil/water pump, or worse?

[climberbry]

Greetings! My 07 4.0 4runner (90k miles) has recently developed a "whine". Tested by taking off serpentine belt, still whines. Dealer thinks it could be a faulty oil pump. Couldn't it also be water pump or pulley(s)? The only reason I can tell that they jumped to this conclusion is that they saw this same thing happen on an FJ recently. Are there any tests that could be done that could determine which it is or isn't (e.g. pressure test)? And, is there anything that I could do to rule out the transmission before getting in too deep in costs here?

Otherwise, car runs great.

P.S. They want $1200 to replace the oil pump.

Thanks for your time!

 

[JEL]

The 4.0 isn't know for being "easy" on water pumps, and you're at that mileage where it's a distinct possibility, IMO that seems more likely than oil pump but others with more experience may have more wisdom than I.

 

[gm350reratliff]

You can rule out the water pump if you took off the serpentine and it was still whining. The water pump on the 4.0 is driven by the serpentine belt. The 4.0 water pumps due tend to weep a little but unless it is constant dripping, it is perfectly normal.

Can you tell if the whine is coming from the front of the motor or the rear ( closest to the transmission)?

 

[progress4m]

You can rule out the water pump if you took off the serpentine and it was still whining...

OP stated that they tested it:

…. Tested by taking off serpentine belt, still whines…

To OP: unfortunately the dealer could be on the right track here..… Sounds like oil pump…

 

[climberbry]

OP stated that they tested it:


To OP: unfortunately the dealer could be on the right track here..… Sounds like oil pump…

progress4m,

So, it sounds like the water pump is not driven by the timing chain, unlike the timing belt engines? I guess that would just leave the oil pump/gears. They said they used a tool to hear where the sound was coming from (they called it something like a sophisticated stethoscope) and they said it was from the area of the oil pump, with the caveat that it could be sound transferred from the torque converter or even tranny.

Thanks again

 

[climberbry]

I came across this article on narrowing down torque converter and transmission whine noise.

Symptoms of a Transmission Oil Pump / Torque Converter Diagnosis

Thinking of checking the transmission filter... Also, wondering why there wouldn't be any idiot lights going off if the transmission pump were restricted in any way... Anyway, this article makes it sound like it is probably not the torque converter, as I get the whine in park and neutral...

 

[progress4m]

progress4m,

So, it sounds like the water pump is not driven by the timing chain, unlike the timing belt engines? I guess that would just leave the oil pump/gears.

Yes, that is correct;
With timing belt engine (in most cases) WP is driven by Timing belt;
With timing chain WP is driven by serpentine (accessory) belt like in 4.0 4Runner engine and as you have mentioned you have the same whine sound with serpentine (accessory) belt off… that leads me to believe that it is oil pump…
OR… there is a chance you have too much backpressure on the oil pump and it makes it whine… have you recently changed your oil and more importantly the oil filter..?

 

[climberbry]

Yes, that is correct;
With timing belt engine (in most cases) WP is driven by Timing belt;
With timing chain WP is driven by serpentine (accessory) belt like in 4.0 4Runner engine and as you have mentioned you have the same whine sound with serpentine (accessory) belt off… that leads me to believe that it is oil pump…
OR… there is a chance you have too much backpressure on the oil pump and it makes it whine… have you recently changed your oil and more importantly the oil filter..?

Actually, I believe the dealer changed the engine oil and filter just before I bought it.

 

[climberbry]

Issue Resolved

I took my truck to another mechanic. Turned out to be just the idler pulley. The dealer doesn't know his a@@ from a hole in the ground.

 

[skott]

Glad you got it fixed, but didn't you say it whined even after you took off serpentine belt?

 

[climberbry]

Glad you got it fixed, but didn't you say it whined even after you took off serpentine belt?

Yes. Actually, it was the dealer's mechanic that claimed to have taken off the belt as part as his diagnosis. He was suffering from cranial-rectal inversion...