Primary chain not allowing IMS to align!

[xtremizt]

Hi!

After having searched online for days, devouring through the service manual and trying as many tricks I know, I come to this forum with great hope...

I am in the middle of rebuilding a 987-1, M97 (3.4) engine that failed when a connecting rod bolt came loose. So far I have the bottom end put together with a brand new crankshaft, bearings, rod, rod bolts, etc. Now the issue that I have is that the primary chain won't sit flat on the teeth crankshaft. Due to which the IMS is being pulled up resulting in the cover not being able to be installed.

I have attached some photos of what I am dealing with, I assume that someone with more experience than myself on a Porsche might have faced a similar issue and can offer advice? Please... :-)

 

[Ahsai]

I assume the tensioner of the chain has not been installed yet? Any free play if you push on the IMS chain paddle (via the tensioner hole)?

Are you sure the chain matches the gears on the crank?

[xtremizt]

No the tensioner hasn't been installed yet. There is some play, yes, but not enough to let the IMS drop lower to line up with the cap. 

 

The chain is original and the crankshaft is new, identical part numbers to one that came out though. If I turn the crankshaft, the chain links will sit properly over a few teeth but then form a kink where it touches a chain guide on either side. Turning it further raises the entire chain off the teeth. I hope I'm making sense here as it's a bit of a predicament to describe via text.. 

[Ahsai]

I see. I think I know what you're talking about. I have seen a post or two about the same problem and I'm trying to find those posts. If my memory serves, it's something to do with how the chain was installed on the crank and chain guide although it's difficult to imagine how because there are not many ways the chain could fit. I think the solution was to refit the chain and chain guide.

 

I'll post again if I find those posts.

Edited October 13, 2018 by Ahsai

[xtremizt]

58 minutes ago, Ahsai said:

I see. I think I know what you're talking about. I have seen a post or two about the same problem and I'm trying to find those posts. If my memory serves, it's something to do with how the chain was installed on the crank and chain guide although it's difficult to imagine how because there are not many ways the chain could fit. I think the solution was to refit the chain and chain guide.

 

I'll post again if I find those posts.

I went on another search mission going through multiple pages of results with various keywords, but no luck ?

Without the tensioner installed, I shouldn't even be having this issue. I hope I don't have to split the cases again. 

[Ahsai]

I found the thread https://rennlist.com/forums/996-forum/851856-ims-tube-totally-misaligned-2.html

 

Please read carefully and see if it applies to your situation as there are different styles of IMS. Good luck!

[Ahsai]

Actually it should apply to you because the problem is on the crank side, which has only one style of gear.

[xtremizt]

On 10/14/2018 at 6:28 AM, Ahsai said:

I found the thread https://rennlist.com/forums/996-forum/851856-ims-tube-totally-misaligned-2.html

 

Please read carefully and see if it applies to your situation as there are different styles of IMS. Good luck!

Thanks again for finding that out for me. 

I kept fiddling with it for a couple of days in order to not have to split the cases and got it right in the end by locking the IMS by using a hex socket in it's rear end while rotating the crankshaft to make the chain sort itself out! I got lucky this time. 

This forum is great, so many more educational tips as compared to most other online forums!

[Ahsai]

Glad to hear you got it sorted without splitting the case!