misfires attributed to lifters 00 996

how many of u have had to replace lifters due to misfire codes??

We see lots of lifter issues with 5 chain engines.. Most of the time they never throw a CEL.. Usually a CEL comes from a variocam related issue.

we've had many......expensive code lite to turn off

I had it on my car. Thank God for CPO.

the trouble is that the lifters deform over time and the top pof the variocam plunger (small area in center) sticks to the bore in the larger section of the lifter... this starts out as sparatic and become permenant. The "repair" is to replace the lifters OR if you are really cheap... pull them out and disassemble them, hone down the edge of the smaller (variocam) part and reassemble them... I have a feeling this type of thing is going to become more and more common. I have detailed pictured of the area I am talking about and will upload them for you tonight sorry, its not good news - at least its something new to talk about and not the same old "hash"

aracer - Is your a 3.4 engine as referenced by Jake Raby or a 3.6 as referenced by Ed. The intake lifters on a 3.4 are different than on a 3.6.

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The OP's title says 00 996, so it's a 3.4 liter.

DOH - me and reading... We had a 3.4 with this, thought it was a lifter, turned out to be a broken valve spring.

ivangene, Jason emailed me about that one.. I helped him with the diagnostics :-) The '00 engine is a 5 chain, the lifters in these engines become sticky due to debris being collected inside them. The lifters only have one hole and are at the end of the oil system, where all the debris ends up. It is fairly common for us to teardown a 45K mile engine and it have 90% of it's lifters stuck in the collapsed position. Nothing solves this other than replacement with an upgraded lifter, an engine flush is THE WORST thing that can be done!

Hell of a catch on the spring. I am so happy to see the level of diagnosis going up and the repairs on these coming in and just getting done, and right back out. Its amazing!! Wasnt that long ago when the 996's had not been opened up and fixed... there really wasnt the "know how" and now its like an explosion... Your rebuild class was the ignitor for the explosion AWESOME!!

Off topic, but I've been continually impressed that Ed can drive his car so fast, it stretches. Assuming this is simply a function of warp speed rather than wind pressure, this may be a practical demonstration of relativity. The faster he goes, the more space it occupies. Amazing pic.

Thanks James...one either goes fast or gives the impression of going fast If anyone is interested I will throw up the originals on a new thread (avatar and sig pics) - kind of interesting to play with photos... I never am quite sure how I end up where I do, and sometimes I dont even know if I like it, but its fun

What kind of time frame is it to get to the lifters? Sorry to hijack...

Lifters are generally a 16 hour job if the lifter carrier is removed and cleaned along with the vario cam components and etc.

I assume thats for a 5 chain motor - leaving the motor in the car, right? Is the 3 chain about the same time wise. I know that getting the cam timing tool in there is really tight REALLY TIGHT - do you drop the motor or just battle it out for space?

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So, if I understand correctly, it's common for a 45k mile motor to have the lifters bottomed out and stuck, clattering away and unable to pump up? This would cause a huge decrease in power and a very noisy motor. Is there a problem with debris laden oil supplying the lifters? Is the filtering system lacking in this area? In many high performance motors only clean filtered oil and sometimes filtered and then screened oil is only allowed to fill the lifters, preventing contamination issues. I understand pure synthetic oil is not the best lube lifter wise as it bleeds down and won't hold pressure like a parafin based oil. If it's not IMS, it's now lifters that freeze.

The 3 chain is more difficult, we made a tool just for doing them in car/ 996. The book time for this is pretty much a joke, it doesn't give any time to clean parts or do the job thoroughly.

OH I would like to hear Jake on this, But from my own research I think what I have come to discover is that there is actually a very tiny amount of oil inside the lifter and it doesnt look to have a way out therfore resulting in the oil that was in there many moons ago is still there despite the oil changes. This is just what I think based on what I have looked at. - Do you see a way for the oil to "leave" or be replenished inside the lifters? In the 3.6 motors I have taken several lifters apart and from the way it looks the oil in there presurizes and then returns to normal presure. The there is a pin that slides across the lifter locking the internal section to the outter section for normal operation (IMO the outter section is allowed to "give" when there is no presure and thus run on the center section of the lifter - correct me if I am wrong) when there is no pressure there is a spring that pushes the locking pin back to the other side. the pin is actually a step pin and the plunger that slides it locks 1/2 of the lifter and the pin itself locks the other 1/2 (side) its very ellegant in its simplistic design and very precision in its MFG.. despite the effort to keep the oil clean there is still signs of debris on the lifters I have examined that cause micro scratching in the sides of the inner lifter (see pics) The second part of the problem is that the upper edge for some reason seems to mushroom out. is that from heat? presure when they "stick"? wear? poorly heat treated parts that dont have enough strenght? I dont know but yes, they will mushroom and begine to stick or not fully retract. these lifters must be replaced. The reasons fro these things happening is a mystery to me. Could be too much lugging around or not changing the oil with the right oil or regular enough intervals... I just dont know. I am tired and a bit scatter brained right now so - this is good, I am curious to hear from others about what is being seen and what the reasons behine them could be please enjoy some close ups - I dont know where my "exploded" views of the internal pieces of the lifter went, maybe I deleted them... last note, if you are local and stop by the shop we have a "model" I made using an old lifter that you can see the way it works, fun to play with...helps to understand the variocam plus system - its a really cool system!! just going to say, choose wisely, some shops are really doing what it takes and some are not...the internal workings are complex and very detailed...I wont say more about that (today)

we have a caymen, owner thought lifter bad......(another lifter story)......however, upon removal of oil filter...yuk........THERE WAS MORE THAN THE LIFTER TO CREATE THAT NOISE......rod bearing got a liitle less bearing on the crank and more bearing in the filter!! LIKE Raby using the 5 chain, 3 chain lingo!!:-).....looks like another 3 chain rebuild at FM. BTW-off topic ANYONE know of a comprehensive document detailing the all the dimensions of the 996 geabox for reference...........performed a bunch of rebuilds but using my own (doh) understanding and pictures for reference. NOTHING from PCNA that represents a proper understanding of the 'FACTORY" (AUDI) SPECS. THANKS m

COMMENTS-Interestingly enough.....failure DOESN'T necessarily translate into "NOISE". Using the factory diagnostic tester and "seeing" misfires can be the first telltale sign. I can only say that we have performed this service MANY times due to the CEL. It's been a not so uncommon failure for a while now and am surprised by this string. It is so AWESOME to see so many of u focused; those pics and detailed line of thought on the lifter issue is wonderful. Makes my job easier:-) wish I had time to spend with u guys more often. M