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Performed · outcome unconfirmed · Original poster
And the assembly procedure used by the manufacture was not meant to be disassembled.
Leading evidence: 'Use by the manufacture was not meant' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'usually in the actuator' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Replace solenoids' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
Downside it only has a 25* capability whereas the "vane type" used on the 3.6 3.8 has a 50* capability.
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Performed · outcome unconfirmed
I'm more familiar with the vane cell actuators used on the VW 3.2 and 3.6 VR6 engines.
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Suspected cause · Original poster
If you are watching cam adjustment on a scanner and one bank is slow to move, or slow to return, the problem is usually in the actuator.
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Suggestion · Original poster
I'll do a video showing how to do a bench on these actuators using 2 bar air pressure and a 9v battery to turn it on and off and verify function on the bench, or if you just got deep pockets just buy new ones, they only about 1k each..lol
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Suggestion · Original poster
If you see green rubber bits in your oil filter, it can come from one of the 4 o-rings, OR the spark plug tubes on the 3.4, that is the only green rubber used on the 3.4 engines.
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Here are the pics of the exploded view of the vario-cam actuator for the 3.4 engine used in 1999 2000 2001 (996) and the Boxster 2.5 2.7 and 3.2 1998 1999 2000 2001 2002.
Failure of this actuator can cause codes P1325 (bank 2) and p1341 (bank 1 ) for DME 5.2.2 .
Failure of this actuator for DME 7.2 can cause codes p1524 p1539 (bank 2) and P1530 p1539 (bank 1)
Looking inside you can see the various parts that make the actuator work, and the problems that can arise. There are 4 green rubber o-rings and 1 nylon "piston ring" that can fail or wear out. A switching valve or "plunger" with a small return spring, an electrical solenoid which can fail.
If you see green rubber bits in your oil filter, it can come from one of the 4 o-rings, OR the spark plug tubes on the 3.4, that is the only green rubber used on the 3.4 engines. So if you see green rubber in your oil filter, or see someone post about green rubber in their oil filter, it comes from either the vario-cam actuators or the spark plug tubes.
Sometimes when the green o-rings fail you can find then hung up on the switching valve or "plunger" which causes the acttuator not to retun to rest position.
The solenoid is just an ON/OFF and usually either works or it doesn't. Testing with a 9v battery while running and watching cam advance on a scanner is an easy test, as is listening for the "click" with engine off
If you are watching cam adjustment on a scanner and one bank is slow to move, or slow to return, the problem is usually in the actuator. A failed rubber o-ring, sticking piston or plunger. This actuator is full advance 25* by oil pressure when switched ON, and is return to rest 0* by the chain torque while running and the solenoid/valve is switched OFF.
I'll do a video showing how to do a bench on these actuators using 2 bar air pressure and a 9v battery to turn it on and off and verify function on the bench, or if you just got deep pockets just buy new ones, they only about 1k each..lol
exploded view
view of the four green rubber o-rings and black nylon "piston ring"
bore of the vario-cam actuator where the piston/tensioner slides
four green rubber o-rings and one black nylon piston ring
tension-er/slack adjuster is a "lifter style" with a large spring also the switchingb valve or "plunger" with small return spring
internal sealing grooves and piston ring groove without o-rings and piston ring
Yep, pretty simple concept. It keeps the same tension on the chain, but moves the "slack" from one side to the other advancing the intake cam buy sliding the whole tensioner assembly/rubbing pads.
It's very robustly built, but can have some simple failures.
Downside it only has a 25* capability whereas the "vane type" used on the 3.6 3.8 has a 50* capability.
It is VERY VERY difficult to remove without damage, so don't attempt unless you are prepared to destroy the assembly.
There is a large wire retaining ring that is "crimped" or "swedged" into place and not meant to be removed, on the large side of the bore.
No internal parts are available.
And the assembly procedure used by the manufacture was not meant to be disassembled. The large retaining ring is "swedged/crimped" into place, and the piston and pad mounts are also "swedged/friction welded" into place on the hollow shaft.
Using these assembly procedures means it would probably be more cost effective to just to CNC a new housing and machine a new hollow shaft.
Very clever, the tensioner is needed anyway so why not make it adjustable? Naturally this is only practical with the 5-chain engine design and can only provide "on/off". I have never seen one like this before. I'm more familiar with the vane cell actuators used on the VW 3.2 and 3.6 VR6 engines.
The 911 Mezger engines use a third type, with a sliding helical gear driven by oil pressure. If you're interested read about my adventures with my P1325 code on my 996 Turbo engine, with pictures of the actuator ->
https://rennlist.com/forums/996-turb...-annoying.html
Yep, I remember when I first saw those sealing rings on the Turbo engine at the four day P10T Class at the Porsche Training Center in Atlanta. My first though was of the fragility and importance placed on those rings, too soft and they would wear and leak, too hard and they would be brittle and crack up.
Looks like yours and others have proven my "gut instinct" to be right..
Good job on chasing down that demon !!! (even if it did take you a while )
Four day training on Turbo GT2 and GT3 engines, I have 17 similar Porsche Certificates
Thanks man, I'm just spreading the knowledge around when I can/feel like it, no need taking it to the grave with me....
That's just with Porsche, I have much much more with Mitsu and FoMoCo . The Carrera GT Training Certificate is the most rare, very few people have been to it, and the class was only given a few times..
Your UAOS is a much needed and fruitful culmination of all that training & experience! While I doubt it will make you wealthy, I hope it gives you a little extra income and a sense of great accomplishment! It's really a huge contribution to this community and the DIY sensibility in general. Keep up the great work!
Thanks dporto , The UAOS has been a good little extra income to make life a little easier. I priced it affordable to everyone and less than the Porsche Motorsport AOS even though it is way more technically sophisticated, and haven't done any big advertising ( not really in the budget) to keep from being bogged down. But I did have to remove my website link from my signature as requested by Rennlist, so it may be even harder for people to find where to buy. So keep up the WOM word of mouth ... But LN Engineering has them now so that will help.
Does anyone know where I can pick up the spring (all the way to the left in the image) that goes under the plunger and solenoid below? It is not a numbered part and places want me buy an entire variocam. I just need one spring.
tension-er/slack adjuster is a "lifter style" with a large spring also the switchingb valve or "plunger" with small return spring
You can buy the one in the pic for $1 plus a small S&H fee. PM me. Snell Gelb lost one from his a couple of years ago, and put the car back together not knowing..lol he had to do it all over after we figured out what was wrong. ...I hooked him up too with the little spring.
Important little bugger !!!!
Your "little spring" is carefully packaged in a cut-out of cardboard and in a small padded envelope, shipping label created, will be dropped of at USPS today, you should get a notice with tracking # in an E-mail.
Don't loose that little sucker they are as rare as hen's teeth (but De Jeeper has a back-up), and only come with a $1K assembly !!!
Don't feel bad about loosing that little spring, here is a long thread where Schnell Gleb rebuilt his engine and lost that spring unknowingly a fought for it for a long long time.........
https://www.renntech.org/topic/50995...w-limit-value/
Ok I promised a simple bench test video. Please excuse the video quality, I had to do the video on my old flip phone, ( really needed 4 hands) my new high tech Sony digital cam-corder evidently doesn't have the proper UHS-1 class 10 memory card to be able to transfer the high def video to my laptop .
Simple te4st shows using a 9v battery to test the solenoid for "click" with only 9v, so if it works with only 9v, it will definitely work with 12v+.
Using only 1 bar air pressure in to the only oil hole in the bottom, the vario-cam moves easily and solidly to full position, then after hooking up the 9v battery the movement is now opposite in function and will quickly and solidly move to full position. Very simple test to unsure the performance of the actuator when not installed in the engine and running..
You Tube
Lee Jenkins at Hartech has taken the time and energy to source the O-rings and rubber piston ring and packaged a kit you can buy for about $125usd, also can get it from Slakker if in the USA..
It is a much needed item and all actuators on the 5 chain engines should be refreshed at this age anytime they are out of the engine...
The "trick" to get the actuators apart without damage is to depress the piston before attempting to remove the big wire spring clip, if you don't depress the piston first, you will destroy the housing trying to get the clip out...
Hi
in my 996.2 engine the actuators leaks internally at the electric conection. I have now no failure message. But I think there will be a problem in the future. Now I have dismanteld the exhaust and you can reach the solenoids more easy.
What is your opinion? should I profilaxy change the solenoids?
Your 3.6 engine ( 996.2) is a "3-chain engine " and is a whole different animal...( Vario-Cam wise )
This thread is for the 3.4 " 5-chain engine " ( 996.1 ) .....
Please start a new thread on your issue and list the fault codes along with any relevant pictures or assessments. You will get the help you need ...
This is a source reference. Confirm exact model applicability in the original material.
