IMS BRG - 1-3 rear timing chain tensioner.
 

1999 2.5L Boxster 5 spd Manual, Engine out of the car.

Replacing the IMS bearing. Removed the 1-3 rear timing chain tensioner. It fired out from the case.
Removed the Oil pump. The slack side of the chain, tensioner side is so tight it is pulling the IMS shaft
against the case on the 1-3 side. I ordered a bore scope to try to see what is happening with that chain.
Does any one know if the chain tensioner plastic guides fail and wedge against the chain? If so is the
guide replaceable with out pulling the head?

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Did you remove the IMS chain tensioner? If you have tension and compression on the chains they will pull one way or another. Did you lock the crank at TDC?

It’s all difficult to know from your post.

^Again, did you pin the crank and lock the cams first?

I followed the procedure in the 101 Performance Projects for Your Porsche Boxster book. Project 14 IMS
bearing removal. I used the 3 setscrew method to lock the IMS sprocket. I marked the cam locations
as per this article.The cam locations have not changed.
Unfortunately, the 2015 updated procedure is not in the book. It includes the pinning and locking of the camshafts.
I do not have the timing tool. So I will have to make one.

Let me get this totally straight. You didn't lock the crank shaft at top dead center nor lock the cams? No? Oh boy, this is going to get interesting. Please post how this turns out in the end. I need popcorn!:corn:

The thread is going on in the 996 forum. You may soon find popcorn there.

Professor:
I reinstalled the 4-6 and the crank chain tensioners. I made a plastic IMS bearing with slip fits on the OD and ID. I used the existing flange to install this bearing
and pull the IMS shaft off the case while rotating the oil pump (cam shaft) in the wrong direction approximately 10 degree. I reinstalled the 1-3 chain tensioner. I rotated the crank one revolution CW to the TDC crank position. I pinned the crank. Checked the timing. Both sides are in time. I have made two cam locking fixtures. Will lock the cams and start the IMS bearing replacement again. I bought the LN eng, ceramic kit. I asked LN eng. if I should use this kit or the roller bearing kit after the fact. No response.
What kit do you favor?

I'm getting ready to change my IMSB in my 2004 Boxster. I noticed the project in the 101 Performance Projects gives a little different method than using the crank locks. I am looking for the best information and ran across your thread. I have not come across the 2015 update. Where did you find it? At this point, I have my locks in place and the crankshaft locked at TDC. I'm not removing anything until I am absolutely sure that I'm doing the correct thing! I hope yours turned out well.

The 101 projects caused me problems.
As the popcorn kibitzers above said, Pin the crank at TDC and lock the cams before doing anything. More importantly,
follow the instructions included with your IMSB KIT. I bought a set of tools to lock the cams and time the engine. I had lifter
problems and had to remove the cams.
Good luck and have fun.
Stan

Stan
I got back onto the Pelican Forum and found a detailed explanation that complimented the book. (I'm printing it so I can stuff it in my book.) I've replaced my IMSB and haven't taken any cam locks off yet. I'm planning on doing that today. Thank you for your reply.