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Jeff, I concur. However, before I move in that direction, there are a few variables I need to address. It may be a few weeks to provide the results of the bore score scope. My purpose is I don't want to do a repair K$ range..I would rather send to Jake and have him do the entire engine and know I have all the possibles covered going forward. I appreciate your willingness to work with me on this problem and I will keep you advised.
I was running DT40 until Jack Raby recommended 10w30 diesel to protect the engine from getting worse if bore scoring was the problem. So I changed oil Fall, 2019. Regardless of what oil I have used, the tapping continues. I have not used a recommended 5w50. Thoughts on this? What about the idle issue, 665 rpm is not correct when hot? Can bore scoring create a very low hot RPM?
Jeff, Loren, and Mike: Here is my data for my BoxS regarding oil pressure and warm-up condition. As you will note, I observed the car for an hour and took readings over that period. Summary of results: Cold temp oil pressure was 89 psi at start-up idle (and no knocking sound) and as the engine fully warmed to 98 degrees C, and oil pressure at idle (665) dropped (at the end of the test period, 60 minutes) resulted in a reading of 17 psi with the a very loud knocking sound. The trend data shows a correlation between engine temp and oil pressure and oil pressure and rpm. One aberration is at the the 48:00 minute mark where the engine/ecm voluntarily raised the idle speed to 800 for 3 minutes. The engine had no knocks and ran like a new engine over that 3 minute period. Then the low idle returned to 665 and the knocking was present until end of test. Please refer to the data collection sheet attached to this email for full test results. Jake Raby suggests a few tests and data collection regarding bore scoring using Durametric. Fuel trim, cam deviation, and rough running index. All data from these variables I have observed is within the range Jake has set on his video. Gentlemen, what is the next step? If you require more data, please tell me as I still have the OPG attached to the port and my PC in my garage. Thanks again! edebesoilpresstest04 BoxS.pdf
Thanks, Mike...I appreciate the compliment !
Oh...one follow-up: what is the thread size and standard for the port I will be accessing?
Jeff, It will be a few days until I can pull a kit together and make the test (once done I will report data...Can you ID the possible locations (schematic) of where I can "tap" in on the block? Ed
Jeff, That was replaced last year upon your suggestion...unless there was an update in the last year, I used the kit purchased at the local Porsche Dealer In Lancaster PA in early 2019. Durametric does not measure oil pressure on a 986...so I need to do a manual setup. Is there a kit made-up to do this for a Porsche 986? Pedro has one to install in the dash...I just don't have the time now to do that install. I am a college professor and because of Covid19, I have to teach this summer. Ed
Sorry...this is NOT my car...but has similar symptoms. I used this as an example for the discussion last year. Ed
Posted last year...idle speed is 670 RPM, OT-Hot (98 degrees C). If increase in RPM happen, noise disappears....as mentioned on prior post. Ed
Loren and Jeff, Thanks for the recent responses. I have additional data to share... Currently, cold start idle is 1100 RPM (+/-10 rpm), as the engine warms, the idle reduces to around 910 RPM. When the engine is at 90 degrees C (800 RPM) at full OT at 99 degrees C, the idle is at 650 RPM (+/- 10 rpm). (At 90 C, the tapping noise begins quietly, then becomes louder temp increases and the rpms fall). On the forums, correct idle is 780-800 RPMs. (If I am wrong here, please say so.) If by increasing RPMs by 20 (say 670 to 690), this quiets the tapping 95%. By my data collection, I am not at the factory spec for idle speed, then perhaps I should correct the idle issue first before I condemn the engine to a lifter repair? First, do both of you agree with my analysis? 2. What could be the cause of the low RPM? 3. My plan would be to start with changing plugs. (Past owner's shop used Bosch 4471's which I believe are incorrect and for 97-99 2.5 L.) Next, remove TB and clean it. (Here is the data from the throttle area: T-Plate POS 1&2 , 3.9 cold, #2- 2.3 hot; TPS1 (.66) hot, TPS2 (4.35) hot). Any other ideas or data I can provide? Again, I appreciate all the advice both of you have shared!! Ed
Hello again Loren and Jeff! Well, the injectors are all good and not emitting a loud tapping sound, just the typical rattle injectors make. Thought it could be the AC Compressor, so I removed the drive belt and started the engine, the tapping started again at 80 C. I have isolated the sound now in the general area directly below the ac compressor. I understand this is where one of the chain tensioners resides. Further research from prior responses to this topic have the possibilities of bore scoring to worn pads. So here is where I am with this investigation: I believe I have moved past the high level of damage, but concluding,... No CELs, It is not a noisy injector, Not the A/C compressor, Not exhaust leak, I have a clean oil toxicology report, The sound can only be heard at idle, however, just a slight increase in RPM say 50, the sound is gone. The reality here is increases in oil pressure results from a rise in RPM is worth considering as a suspect. Here is some data from Durametric from my analysis today all through from cold start and after 30 minutes of driving: (If I need to post other data, just state description) Camshaft Position Variance Offset 1: 1.28 Camshaft Position Variance Offset 2: 1.33 I believe a difference of 6 and under is favorable and a difference of 6 and over is a concern. IF I have no other evidence (i.e. CEL's, failed oil report, and positive Camshaft shaft data, etc). I am now down to a few other possibilities: I replace the tensioner regardless and determine if the problem still exists? Noisy lifter? Do I run an engine cleaner and if so, what do I use? Then a complete change of oil and filter. Check the #4 coil pack and plug. (Number 5 was fine). Oil pressure issue at idle? Take to Porsche Service Center for cam cover removal and diagnosis? Any other ideas?? I would like to repair the car myself. I have only put a limited amount of miles on the car over the last 3 years. It has remained mostly in the garage because I am afraid to drive it. Ed
Loren and Jeff....Using the advice provided last year, I am still trying to solve the tapping sound of my 986S. In review here is a brief report. Car starts fine. I have NO CELs. On cold start, there is no tapping noise. Once started and engine temp is rising, tapping starts on the left side around 180 degrees and continues to become louder as the operating temp hits (210 degrees). Now, here is where I am in my investigation: I have taken a sample of oil and sent to LN for analysis. There were no issues to report. The report had all "green" areas. I was on the phone with a Porsche vendor who asked if I have Durmetric and have I checked the injectors? I borrowed an "ears" analyzer and I can confirm the ticking is coming from the #5 cylinder on the left side of engine when at OT. When cold, there is no sound, in fact both sides have no noise prior to OT. I went to my Durmetric and used the injector "defeat" feature. I tried all 6 cylinders and when I removed #5 from the circuit, the ticking sound stopped. When I placed it back in operation, the ticking began about 8 seconds later. Have I confirmed that the injector is failing? I plan to replace the plug, coil pack and the injector in that order. Am I thinking correctly here? Ed
Thanks for referral....after viewing videos, I noticed there are some statements and conditions that do not match my symptoms. I will do the spark plug torque, inspect oil filter element, view drained oil from latest oil change, and send oil for analysis. Have ordered Engine Ear to determine if "ticking" is case related or cam cover. Will report when I have more info...Thanks to GSpence2, and Ahasi, for input!
Here is a link with the ticking sound. The engine is at 81 degrees C. Please note after the rev-up, the ticking quiets down for a few seconds, then after the idle re-establishes itself, the ticking returns. Will try requested test on variocam hopefully later today. More apparent from drivers side of car, than right. Ed