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UAL96AMT · 03-18-2024, 09:47 AM

I have a question regarding a rather strange reading and symptoms i'm experiencing on my '99' Boxster tiptronic 164K miles. I purchased this car not running. It had a bad transmission but included a replacement with the car. The price was low enough that I figured, "lets take a chance". The seller claimed the engine was good, just a bad tranny. Okay, like I said the price was right. After towing the car home I started straight away and removed the engine/transmission assembly so that I could split the two and replace the transmission. This is my first Boxster... I also learned about various small items internal to the engine that should be replaced while the engine was out. It included an LN Engineering IMS bearing, Vario Cam Pads, cam chain guide rails, and a bunch of other stuff. All went well and the car sprung to life without hesitation and runs smoothly and evenly. Fast FWD 6 months... SAI fault CEL went on then off. Then SAI CEL illuminated and stayed on. I went through the steps of checking the SAI system out. Fan runs and operates, puts out good air. To make a long story a little shorter I ended up replacing every single component in the SAI system including the fan. No Help! I then went to check intake manifold vacuum to see if there's an issue there. 13in Hg steady. I felt this was a little low and since the SAI system is powered by vacuum and actuated by electricity I decided to check cam timing with my Launch CRP129 scanner. I found that bank 2 cam was off by 756.32 degrees when at operating temp, and upon first start up it's 25+ degrees then starts climbing. Since these readings are impossible I threw a Hall sensor (cam position sensor) at bank 2. The results were the same. At this time I have removed the engine (again) to check timing. it's still dead on, no issues with timing, and yes, it runs fine, only issue is rather low intake manifold vacuum and SAI fault. I have rung out all associated wiring on the engine harness, and associated hall sensor wiring. Ring out good. At this time I'm at a loss. I can find no obvious faults and am considering throwing a vario cam actuator at bank 2. Has anyone come up against this set of problems before? Thanks for the interest and assist.

03-18-2024, 09:47 AM	#1
UAL96AMT Registered User Join Date: Mar 2024 Location: california Posts: 3	Untenable cam timing results I have a question regarding a rather strange reading and symptoms i'm experiencing on my '99' Boxster tiptronic 164K miles. I purchased this car not running. It had a bad transmission but included a replacement with the car. The price was low enough that I figured, "lets take a chance". The seller claimed the engine was good, just a bad tranny. Okay, like I said the price was right. After towing the car home I started straight away and removed the engine/transmission assembly so that I could split the two and replace the transmission. This is my first Boxster... I also learned about various small items internal to the engine that should be replaced while the engine was out. It included an LN Engineering IMS bearing, Vario Cam Pads, cam chain guide rails, and a bunch of other stuff. All went well and the car sprung to life without hesitation and runs smoothly and evenly. Fast FWD 6 months... SAI fault CEL went on then off. Then SAI CEL illuminated and stayed on. I went through the steps of checking the SAI system out. Fan runs and operates, puts out good air. To make a long story a little shorter I ended up replacing every single component in the SAI system including the fan. No Help! I then went to check intake manifold vacuum to see if there's an issue there. 13in Hg steady. I felt this was a little low and since the SAI system is powered by vacuum and actuated by electricity I decided to check cam timing with my Launch CRP129 scanner. I found that bank 2 cam was off by 756.32 degrees when at operating temp, and upon first start up it's 25+ degrees then starts climbing. Since these readings are impossible I threw a Hall sensor (cam position sensor) at bank 2. The results were the same. At this time I have removed the engine (again) to check timing. it's still dead on, no issues with timing, and yes, it runs fine, only issue is rather low intake manifold vacuum and SAI fault. I have rung out all associated wiring on the engine harness, and associated hall sensor wiring. Ring out good. At this time I'm at a loss. I can find no obvious faults and am considering throwing a vario cam actuator at bank 2. Has anyone come up against this set of problems before? Thanks for the interest and assist.