Question about belt idlers

[ZiprHead]

99 Q45. I'm wondering about the belt idlers on this motor. One of my idlers on the A/C belt circuit has started whining. I know it's in the A/C circuit because the sound changes when I turn on the A/C. I've also got an oil leak and can't get in there to see where it's coming from but the stains on the concrete seem to be below the idler area. From looking at the idler parts here:

https://www.infinitipartsnet.com/?p=cat ... 45%20idler

I'm wondering if these idlers are lubricated by engine oil. As the idler squeal has gotten worse, oil leaking has also increased. It would be so great if the idler was the source of my oil leak because anything else will probably be so much more expensive to repair.

Am I onto something or is it just wishful thinking?

[my12by60]

Unfortunately, the idler pulleys do not retain any oil. The whine is probably just a bearing that is going bad in one of the pulleys. I had a bunch of oil leaks when I bought my 2000. The two heavy leaks were valve cover gaskets and the oil pressure sending unit (driver side of engine down in the oil filter area). After getting these areas taken care of, I still have a much smaller oil leak which I believe is the front timing cover seals. This leak is slow and tolerable as it is only a few drops per day. The timing cover seal leak is on the front of the engine in the area of the all of the pulleys. The front corners of the valve covers can also leak down the front of the engine. You might need to go to a car wash with some degreaser to clean as many engine areas as you can. This is what I did which helped me to figure out which areas I needed to focus on to stop or minimize the leaking. At my next oil change, I am going to use some Lucas engine oil stop leak and some high mileage oil to see if those will slow or stop the remaining timing cover seal leak that I am dealing with.

[ZiprHead]

Thanks. Wishful thinking then. I'd never seen an oil fed idler before but the complicated nature of the idler as shown in the exploded view made me wonder.

My oil leak is on the driver side. I know the valve cover gasket replacement on that side of the engine is pretty pelican (big bills).

Thank you very much for your help.

[Skibane]

Yes, bad idler pulley bearings are common problem on these vehicles.

Rather than replacing the entire pulley assembly, it also possible to replace just the bearings - if you can locate good-quality replacements.

(There are dozens of grades of bearings that will physically fit, but some of the cheaper grades won't last long enough to be worth the trouble.)

At one time, member TexasOil was selling complete bearing sets for a reasonable price - but apparently, no more.

[EdBwoy]

You might find the part numbers & other tidbits mentioned within this link helpful as you embark on this.
how-to-remove-ac-idler-pulley-t610972.html

[ZiprHead]

Thanks for the tip, Ed. I'll check it out.

[ZiprHead]

Anyone know a good source for a replacement A/C idler pulley? Infiniti part number is 119251P102 or 119251P103 (newer number). Dayco has pulleys for the alternator and water pump but not for the A/C belt circuit. IPN.com wants almost $85 for one plus I assume another 15 for slow shipping.

ETA: orderinfinitiparts.com has it for $75 plus s/h.

[EdBwoy]

I saw some Rockauto part numbers in that thread I linked. I think they said the replacements were a little smaller in diameter, but still functional.

Since I wanted to keep things as true to OEM as possible dimensionally, I chose to buy bearings and press them in.
But otherwise, if you want brand new OEM, it seems like everyone is around that 70-Dollar price range, even ebay vendors.

[ZiprHead]

Out of stock at Rock Auto. Genuine parts on eBay are a little cheaper but have free shipping so I think that's the way I'm going to go.