Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical chat

Reply
 
LinkBack Thread Tools Display Modes
Old 11-19-2017, 10:48 PM   #1
Registered User
 
Join Date: Dec 2014
Location: SF Bay Area
Posts: 239
Timing 360 Degrees Off. What is the quickest way to correct?

Hey Guys,

I need help with the most appropriate and fastest procedure to fix my mistake. I was replacing a bad lifter on bank 4-6, but I set the engine to the wrong TDC (the index cam was pointing outward instead of inward). I only realized when I put it all back together and went to check the timing.

What I was thinking of doing is:

- Remove the 4 bolts on the exhaust cam sprocket (see below) to allow it to rotate 360 degrees

- Undo the chain tensioner to relieve some pressure from the sproket
- Lock the cam in position with the cam holding tool
- Rotate the engine 360 degrees
- Check the timing (should be correct now)
- replace and torque the 4 bolts on the exhaust cam sproket

Edit: this is a 5 chain engine

Let me know if I'm missing something or if my procedure doesn't make sense.

Thanks!


Last edited by martsink; 11-20-2017 at 08:35 AM.
martsink is offline   Reply With Quote
Old 11-20-2017, 03:55 AM   #2
Beginner
 
Jamesp's Avatar
 
Join Date: Mar 2013
Location: Houston
Posts: 1,659
Garage
The year of the engine might make a difference, 5 chain versus 3 chain after 2003.

I would not attempt this until one of the more experienced members chimed in. Ok, I would, but I view mechanical disasters on my own stuff as "learning experiences". It might be safer to take to long route by did assembling and reassembling.
__________________
2003 S manual
Jamesp is offline   Reply With Quote
Old 11-20-2017, 08:49 AM   #3
Registered User
 
Join Date: Dec 2014
Location: SF Bay Area
Posts: 239
Quote:
Originally Posted by Jamesp View Post
The year of the engine might make a difference, 5 chain versus 3 chain after 2003.

I would not attempt this until one of the more experienced members chimed in. Ok, I would, but I view mechanical disasters on my own stuff as "learning experiences". It might be safer to take to long route by did assembling and reassembling.
Haha I'm on the same page as you. Where's the fun if you don't completely f something up once in a while...

Its a 1999 car, so a 5 chain. I figure its already at TDC, so turning the engine should not cause any damage, granted I hold the exhaust cam locked in position.
martsink is offline   Reply With Quote
Old 11-20-2017, 02:59 PM   #4
Registered User
 
Join Date: Dec 2009
Location: Orange County, CA
Posts: 1,261
Quote:
Originally Posted by martsink View Post
Haha I'm on the same page as you. Where's the fun if you don't completely f something up once in a while...

Its a 1999 car, so a 5 chain. I figure its already at TDC, so turning the engine should not cause any damage, granted I hold the exhaust cam locked in position.
Since our engines are "interferience motors" I doubt that you will be able to rotate the crank 360deg without the piston hitting the valves...
Perhaps you may be able to 'walk the cam' while rotating the crank to avoid interferience. (I did it a couple of months ago on the Alfa Romeo because forgot to lock the tensioner and the timing belt
jumped a theeth but was able to set the timing without removing the cams.
Gilles is offline   Reply With Quote
Old 11-20-2017, 03:41 PM   #5
Registered User
 
Join Date: Feb 2005
Location: It's a kind of magic.....
Posts: 5,157
The correct way to do this is to remove the cams from both cylinder heads, closing all the valves. Then rotate the engine to true TDC, and start over reallocating the cams.
__________________
Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
JFP in PA is offline   Reply With Quote
Old 11-20-2017, 04:06 PM   #6
Registered User
 
Join Date: Dec 2014
Location: SF Bay Area
Posts: 239
I thought about this some more and yeah, I guess i have to start over... Thanks for the help!
martsink is offline   Reply With Quote
Old 11-21-2017, 08:01 PM   #7
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,011
It is very easy to get confused or disoriented doing this. Just follow the entire FSM sequence. If you want a toe-curling example of what a mess you can get into and the color charts + tools + advice to get out of it, hop over to Renntech 986 Forum.
You have to be absolutely sure you get TDC+valve overlap.
This is not a job to re-do ! Access is horrid.
https://www.renntech.org/forums/topic/51555-cranks-but-no-start-misfire/

Gelbster is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 11:16 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page