I believe it does ('placebo affect applies to cars'), my engine seems smoother and quieter and more powerful after changing the secondary chain tensioners yesterday...and my love for the car has also inreased a ntch or two, if that was possible.!!? LOL..Allan

 

It definitively works on cars!

Whenever I detail my car, it runs better.

When I change my oil, she runs better.

Or maybe I just think it does, lol??
Vector

 

I washed by XJ8 and changed the oil yesterday -- this thing's going to purr today!!!

 

I believe someone above mentioned using tape on the bit. That's the safest bet in my book. I use this often, especially when I'm trying to not drill too deep into something.

Clean the bit really well, then put a number of layers of black tape on the back side of the bit. Roll it on about 1/8" thick, then it cannot possibly fall through. If desired, leave about 1/4" of the end exposed so you can still grab it with vice grips. I always used my fingers, and never had trouble getting the orafice clean, but maybe mine was never very dirty.

This is not the correct bit, and the tip is broken, but I used it just to take this photo to show an example.

 

How about six inches of coat hanger wire with a loop rolled at one end?

Or one of those metal kebab skewers?

 

Now you're talking! I think I'll try one of those ideas.

 

[QUOTE=Vector;766505]I read the instructions about cleaning the part load breather with a drill bit every time you change the oil and I have done so for all of my DIY oil changes.

There is a caution in the instructions to be careful and to not DROP THE DRILL BIT INTO THE CAM COVER!

Well, today I dropped it!!....>>>>>>

Well Vector my son...you have been getting carried away ;o)=)

For starters, it is not necessary to clean said orrifice every time you do an oil change....that's patently excessive.
The correct proceedure is once every 30-40,000 miles.

You should not be using a drill bit by itself...far better to use one of those pencil chuck holders that lapidarists use to hold your drill bit.
Check my Power Base pics for the proceedure.

The Part Load Breather has a 2.5mm orrifice and the idling and slow speed smoothness relies on this size.
Excessive cleaning will alter the hole size.

Now, unless your car operates in an extremely hostile environment, ie a lot of stop start driving over very short distances and using poor quality, that constant cleaning is a NO NO! ;o]
The PLB hose gets brittle enough with heat work hardening without constantly
placing iot under stress by taking it apart.

It's imposible for the drill bit to drop all the way into the cam shaft housing because there is a baffle plate built into the breather assembly.

Far better to err on the side of caution than to get over enthusiastic about orrifice cleaning....reminds me of a joke....not repeatable here ;o)=)

 

Ok, so I decided to check out my car -- first off, I couldn't find the tool to take off the PLB tube, so I improvised with a long, skinny needle nose pliers (see photo) that I could gently push into the slots and it easily popped the connector off. Next, I tried to take a photo of the inside where it might need to be cleaned (see second photo). It looked clean, but I wanted to jam something in there to see if it came out clean. I didn't have a 3/32 drill bit, so I used a 3/32 Allen wrench and the next one smaller. Didn't want to force it down too far, so I just wriggled it around a little, and very carefully, and it came out clean every time. So, I guess mine was cleaned by my mechanic when the tube was replaced, or for some reason I'm either not pushing in far enough or it just wasn't clogged. My idle is slightly rough, that's why I wanted to check it out.

 

Maybe the result of the placebo effect, but I do believe my engine is running better now. Even seems to have partially fixed my ride quality issue that I've been discussing in a different thread.

 

I didn't see a response to this question. The TSB notes the last affected VIN is F25708. My VIN is F29932 ('01 XJ8). Further, the TSB was amended in 2004 so any mistakes in numbering would have likely been cleaned up by then. Just curious as to whether anyone has knowledge *why* they stopped recommending this procedure midway through the MY?