Injector sleeve and injector O-ring lifespan

[bugstrider]

Hello everyone,

I've been doing a lot of forum research on an up-coming repair that many if you have done. In the PPI I had done on this car recently, the mechanic reported that the car had unmetered pirate air getting past both the injector and sleeve o-rings.

From what I've gathered, the injector o-ring replacement is pretty straight forward, however, I think the sleeve o-ring will be a little more of a challenge but it's doable.

Now here is my main question. In researching the cars maintenance history, both sets of these o-rings and sleeves were replaced in 2001/2002 and for rounding sake, have 60k miles on them. Is this a normal life span and should I even worry about the injector sleeve o-rings?

Cares, comments, or concerns would be greatly appreciated.

Cheers Trevor

[timmy2]

If the mechanic detected air leaks then change them...
O-rings have a life span of about 10 years. Yours are due.

[allaircooled]

I'm kind of in the same boat as you. All though I haven't detected any leaks around my injector sleeves, I have all my intake runners removed from the engine all ready. Mine were done sometime before I got the car and I have owned it for about 10 years now. I all ready have the parts so figure I might as well take care of it now.

[Bob Kontak]

Originally Posted by bugstrider

..............however, I think the sleeve o-ring will be a little more of a challenge but it's doable.

Believe the orange sleeve is crimped into the runner. Use a dremmel to shave the squeeze points down if necessary. I don't remember what type drift I used to re-set them. Maybe just a center punch.

Probably biggest risk is breaking parts off of the sleeve and have them drop down onto the back of the intake valve. May be wise to pull a few of the easy runners and get a system figured out before tackling the stinker (#6) if you do it in place.

I replaced mine in 97 and then replaced again in 2010 as I had the engine out. They were getting hard but not as hard as when I changed the originals. Ten years is a reasonable time window.

[bugstrider]

Thanks for the input everyone.

Allaircooled, I love the direct approach. Not much more is needed...."Yours are due", lol

As mentioned above by Bob, my major concern is having a piece drop into the intake. My plan is to rotate to TDC of each cylinder as I progress. It is my belief that should that occur, it would make it easier to retrieve any FOD that might be there. From earlier posts, I can use the dowel with grease to get any foreign material out, compressed air, and then scope with the new little bore camera the Mrs. got me for Christmas a couple years back. I haven't had a chance to see if the three metal set crimps/punches have been removed. In a perfect world, removing the intake runner would be best since they could be thoroughly cleaned. However, this being our first 911, I am concerned about creating a bigger issue with the CIS system by disassembly since I'm way behind the learning curve.

Cheers Trevor

I can't believe I waited 45 years before getting a 911

[Bob Kontak]

I would pull an easy runner off, find out what threaded tap will fit the skinny part of the orange sleeve bore easily and use that to extract the part. Or at least something along those lines.

Maybe a dowel the same size as the bore with some super glue? You will know if the part has integrity when it pulls out.

[nicfranc]

I tried this method on runner number four and was successful but it was nerve wracking worrying about pieces of the brittle
sleeve breaking off and falling into the intake.I wound up pulling the whole CIS off and am glad I did.
I was able to install gaskets and O-rings to the box as well as check for cracked hoses and lines.
It is mostly labor the parts are inexpensive. Now my engine runs great.

[Bob Kontak]

Great googly-moogly. An easy out. How easy is that?

[Charles Freeborn]

I used an easy out too. Worked well. I also swabbed out the hole with numerous long handled q-tips and solvent. Was a gunky mess in there.
If you really want to be careful about it all, rotate the engine so at least the intake valve is closed on each cyl. Then you can shop vac - blow out any debris that falls in.
-C

[bugstrider]

Thanks again for the all of your input. Box showed up today carrying all sorts of good things for our engine.

Injector sleeves, seals, intake seals, shifter bushings, and security lug nuts, and a nifty injector removal tool. Its like Christmas but in January.



Nicfranc: In looking at your picture, the old sleeve has a gouge as if you extracted it without removing the metal factory crimp. Was that the case or is it just a scratch?

cheers

[nicfranc]

Nicfranc: In looking at your picture, the old sleeve has a gouge as if you extracted it without removing the metal factory crimp. Was that the case or is it just a scratch?


I used a Dremel tool to remove the little indents and after new sleeve was installed I made new indents with a punch.
I also rotated engine on number four cylinder to TDC and used a shop vac to remove any debris that might have fallen in.

Again after doing the number four runner sleeve while in the car I then decided to remove the CIS and work like a Gentleman.

With the CIS out you can check everything and replace all worn parts, gaskets,hoses, lines and such. You want to make sure you have no fuel leaks or vacuum leaks.
I discovered that the aluminum vacuum pipe under the air box was broken and there is absolutely no way I could have seen that and I would have never resolved the vacuum leak that was making my engine run poorly.

The best thing about the process is that I became familiar with the system and am now comfortable working on it. I would recommend getting some gauges to check the fuel pressure. This way you have a base from which to work.You don't want to just guess and start replacing parts as it could get expensive.

I am an old VW guy and this is my first Porsche. With the help of this Pelican Community I have had no problem making the transition. It is not that difficult just take your time.