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There is still the vacuum issue. But you would have to use a smoke machine because of the flashing CEL You could try disconnecting the MAF. If that helps the rough running try the voltage and resistance test for the MAF. I am trying to exhaust the list of easier items for you. " Checked the cam timing and both banks are on the mark aligned with the timing notches while flywheel at TDC. " I presume you mean you confirmed the exhaust cam is in the correct position. What about the Inlet cam notch ? Did you work on any area of the engine before this rough running happened ? AOS for example.
Timing tool. With the engine in place you can't use the big timing tool.Pity because it works great out of the car ! We can tell you how to time the cams to the engine at TDC when you are ready. You lock the crankshaft at TDC for cyl 1 or 4 (depending on the Bank you are working on), hold down both cams with the saddles and turn the cams using a 22m wrench on the camshaft - very very carefully. If you are very careful in allocating the cams little or no adjustment will be necessary.I use assembly lube on the saddles.
First make sure you got all the bolts from the cam cover. Some are rather concealed.It may be hard to dislodge the cover. Find the pry points and be very careful not to break off a tab on the edge of the cam cover. Bank 2 Tensioner for the IMS to Ex Cam chain is under the a/c compressor.It acts on a huge 'paddle' to tension the long chain Do not confuse this(like Pelican do) with the Variocam actuator -that they also call a tensioner. That Variocam unit sits between the 2 cams .The real Tensioner is under the a/c compressor. That is why we never call the Variocam actuator a tensioner.The short cam to cam chain is only for transmitting motion from the exh cam sprocket to the Inlet cam.This is the one with the colored(sometimes) links that has the tricky spacing between divots on the sprockets of the Exh and Inlet cams.
All my comments relate to Bank 1 on the M96 Boxster engine. The 3 o'clock descriptors relate to the hour hand of an imaginary clock face when facing the notched end of the inlet cam.
If you have any doubts about the Lifters 'ticking' , now is the time to remove/check/replace and consider trying to measure for wear in the bores of the lifter carrier.Yes I am paranoid because this is a very time consuming job to do - twice or 3 times ! Lifters have dropped in price now that generic replacements have been identified.
Broken Bolt See Post 11 here: https://rennlist.com/forums/996-forum/994577-welding-on-the-car-engine-disconnecting-the-battery-only-step-needed.html and https://rennlist.com/forums/996-forum/989630-exhaust-bolt-broken-in-head-don-t-panic-get-this-simple-drill-guide.html Stainless steel stud kits are available inexpensively on EBay. No more bolts !
The link you gave has one blurred photo of the notch at the end of the Inlet Cam of Bank 1. It is very important because it shows the controversial "2.45" position not the 3.00 position of the notch . This is for TDC Cyl 1 ,Bank 1.That is also what the FSM shows in a diagram. See the 2nd photo here: http://www.rennsportkc.com/anatomy-of-an-m96-engine-rennsport-kansas-city/
Schnell Gelb replied to Kim's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)If you do not need to Pass a Smog Test ,just use extenders on the 2 new rear O2 sensors ? Just be careful you get the correct design to fit the limited space. Of course this would be illegal in many States but not yours ? It would fool the rear o2 sensors into not throwing a code even if you gutted the cats I say "gutted" because old cat bricks get loose and may restrict the exhaust flow. I am not recommending this just offering a theoretical
Schnell Gelb replied to RedRotors's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)So to eliminate a lot of variables,why not do as suggested and idle the engine with the MAF cable disconnected at the MAF ? Not a brilliant suggestion but quick,simple,does no harm and costs nothing. MAF problems sometimes set no codes. You must have codes associated with the rich stall condition? If you disconnect the battery ,remember to follow the Initialization Procedure
How to check Cam Timing with a Misfire: You need 2 Tools imho: 1. Durametric -to read Actual Values and Deviation. Also check the specific misfire codes. 2. The Baum or LN tools to physically set or check the timing of the 2 Camshafts. The problem is you may have a flashing CEL so running the engine any longer than necessary is bad. You can eye-ball the half-moons and the Inlet notch to get maybe +/- 20 degrees Crk. Almost useless. Before you consider removing the Camshaft Cover to investigate ,do some research or start a separate Thread because access is awful with the engine in place. Check the many easier issues like basic maintenance, MAF ,Vacuum Leaks. For example the AOS hoses/connectors/seals. Disclosure: I am working (again I am embarrassed to say!) on a Bank 1 misfire and am investigating every alternative to removal(again!) of the Cam Cover. Mine is a 2001 S with a recently rebuilt engine.Codes are P0300,0301,0305 .These are Porsche Codes 62,63,67 per Durametric.. In my case the Actual Value for the timing (cold)on Bank 1 at idle is negative 10 degrees. Bank 2 is less than 2 degrees. It runs rough stinks of gasoline and has a flashing CEL with codes as above. New plugs.coils,injectors,new CkPS,new cam to cam timing chains but a suspect Variocam Actuator. Strangely the static Cam Timing is perfect. The IMS to Cam chain is original but 'good' the chain tensioner seemed very strong when I did this same job a month ago. If you must remove the Cam Cover - the best write ups have recently lost all their photos due to the Image Hosting Providers going awol. Insite had the best and it was linked and used many times .But without the photos it is not as usful. The FSM has the basics. For example: http://986forum.com/forums/performance-technical-chat/26418-diy-setting-cam-timing-m96.html Maybe someone on RennTech has a solution ? Pelican has a useful Section intended for the 996 http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/16-ENGINE-Camshaft_Swap_and_Valve_Train_Repair/16-ENGINE-Camshaft_Swap_and_Valve_Train_Repair.htm or the Boxster version - but you already have the book? http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner.htm 1.Just be careful about Wayne's ambiguous use of "Chain Tensioner". Sometimes Wayne means the Variocam Solenoid+Actuator assy., sometimes he really means one of the 3 actual Chain Tensioners. 2. I don't understand why he removes the Camshaft Sprocket (Figure 8) from the Exhaust Camshaft with the IMS-to-Cam chain still under tension. For Bank 1 that you are concerned with ,the big nut for the Chain Tensioner is easily accessible on the underside of the engine . Why not remove it before trying to remove the Sprocket ? 3. Note Fig 18 - one of the few remaining photos showing the correct (8) link spacing between the cams.Mark the 'divots' with a paint pen.New chains may not have the helpful colored links ! 4. It may not be a Timing error if the notch of the Bank 1 Inlet cam notch points slightly upward (& toward the passenger side rear wheel) with the engine at TDC and the Exhaust cam correctly positioned with the LN tool.The FSM shows the notch at roughly 2.45 , not 3.00. 5. Access requires removal of many other parts. Then need to drop the engine as far as possible. If you are not using a lift ,this would be difficult.
Cam Timing - maybe, but it would have to be a common component to both Banks if 1,5=Bank 1 & 6=Bank 2 are causing the codes. That is why I suggested the basic cam timing check by removing the green plugs. Vacuum leak is still a possibility if the misfire is caused by an excessively lean condition in those cylinders. The plug color may give clues? My speculation is not authoritative so best for you to gather evidence and let the smarter guys comment.
Agree with the deferred maintenance diagnosis .If the plugs,seal,coils are old - it is prudent to replace all in my experience.It will eliminate all those issues from any future diagnosis. Seems you have misfire on cyls. 1,5,6. So both Banks are affected. Are you sure the 6 was not a 3 ? I ask because that would have limited the diagnosis to Bank 1. In turn that would have suggested a need to check the static timing (the green plugs job). Were the plugs tips wet with gasoline or oil ? Was the body of the plug wet with oil(seal leakage)? Once you've done the parts replacement work let us know what codes you get? A good idea to poke around looking for vacuum leaks. For example the AOS hoses and their brittle connectors and missing seals?
There is a metal washer inside the Green caps. Use a SOFT scraper. I use a hard plastic. Acetone /alcohol will soften it. You need a perfect surface.Don't drop bits of old sealant . Before you go furrther make sure you mark the Scavenge pump orientation.You need a replacement (giant size) "O" ring Ask here about the stage at which you may want to remove the big chain tensioer. that bears on the paddle for the IMS to Cam chain. Great progress and loved your electrical diagnostics !