Welcome to the North American Subaru Impreza Owners Club Monday April 21, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 09-04-2013, 03:22 PM   #1
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default Used TDC when installing timing belt on rebuild.

As the title says I used the wrong mark when installing the timing belt and figured that out when she wouldn't start. It's a new engine rebuild. I understand that the engine is an interference design in respects to the valves but what about the pistons to valves? The engine turned freely by hand. By my figuring, if the pistons are lagging the valve train by 90 degrees then only the intake valves are at risk. I also read that possibly Subaru may have engineered the engine so that there is no valve to piston contact. Has anybody (not afraid to admit it) done this and was able to correct the timing without damage? Thanks.
* Registered users of the site do not see these ads.
Portland Dave is offline   Reply With Quote
Old 09-04-2013, 04:01 PM   #2
Dillinja666
Scooby Newbie
 
Member#: 332644
Join Date: Sep 2012
Chapter/Region: SCIC
Location: A whales Vagina
Vehicle:
07 STI
It's white

Default

Yep, if you can spin it by hand you didn't contact. You know when you contact cause you can feel it unless you were using a huge bar when you were turning the motor over and bend the valves by hand. Re-set your timing belt and give it another go.
Dillinja666 is offline   Reply With Quote
Old 09-04-2013, 04:28 PM   #3
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default

Hmmm, when I said by hand I meant using a socket and breaker bar. The only thing I think I ever felt was resistance when the valves were compressing.
Portland Dave is offline   Reply With Quote
Old 09-04-2013, 04:45 PM   #4
tibug
Scooby Specialist
 
Member#: 273906
Join Date: Feb 2011
Chapter/Region: NESIC
Location: Yes, I feel wonderful tonight.
Vehicle:
2003 Outback
I like trees

Default

That sounds normal. You can take the spark plugs out to eliminate the compression variable and see how freely the engine spins. If timing is off enough then the pistons will hit the valves After a little google digging, some people have done the same thing (crank 90 degrees off) with no ill effects...

http://bbs.scoobynet.com/general-tec...ming-belt.html

...As Dillinja said, I'd reset the timing and see where that puts you. If the engine rotates freely with the cams and crank correctly aligned (take the spark plugs out to get a better feel) then I would just fire it up. I think the alternative is to remove the heads and check all the valves and pistons for signs of impact. I definitely would not do that, but if you wanted to be 100.00% sure, that's the way to go...
tibug is offline   Reply With Quote
Old 09-04-2013, 05:31 PM   #5
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default

The engine was on the bench with no plugs when I checked it. Thank for the link, my searches never pulled that one up. My hope is that the intakes are starting their way closed when the piston reached top and you get a near miss instance.
Portland Dave is offline   Reply With Quote
Old 09-04-2013, 10:29 PM   #6
Dillinja666
Scooby Newbie
 
Member#: 332644
Join Date: Sep 2012
Chapter/Region: SCIC
Location: A whales Vagina
Vehicle:
07 STI
It's white

Default

Ya man you're fine. Ive seen these things scary far off and after a correct installation of the timing belt run perfect. If you made it around by hand with a breaker bar and you were not giving it serious effort to actually bend a valve by hand you're fine to reset everything and throw it in the car. The poor subarus I have seen roll into my shop when I was spinning wrenches would make you cry sometimes. Couple teeth off timing wise on a hand spun motor = no issues. Hell I had one where the guy kinda did the same thing cept he couldn't make it spin all the way around so he brought it in. I thought he had something 180 out and tried every combo of cam/crank there was. I ended up pulling off the head thinking he bent something and found the hose clamp for the fuel line had fallen in the cylinder while he had the heads off and he didn't see it. Slapped it back together with a new head gasket ( guess the right side the first time!) and off it went.
Dillinja666 is offline   Reply With Quote
Old 09-07-2013, 05:58 PM   #7
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default

I got the timing straightened out and she started right up. I ran her for 10 min at 1500 rpm. Stopped allowed her to cool off and topped off fluids.

Now another issue has come up. At a cold start everything sounds good but when the engine gets up to temperature I get a knocking sound that I've narrowed down to the left head on the exhaust side. A consistent volume just above the normal valve train noise. Reminds me of a bad lifter but we don't have those. Sticking valve?
Portland Dave is offline   Reply With Quote
Old 09-07-2013, 06:12 PM   #8
Dillinja666
Scooby Newbie
 
Member#: 332644
Join Date: Sep 2012
Chapter/Region: SCIC
Location: A whales Vagina
Vehicle:
07 STI
It's white

Default

valves adjusted properly?
Dillinja666 is offline   Reply With Quote
Old 09-07-2013, 07:03 PM   #9
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default

As far as I know, I had Bearing Service here in Portland OR do the work. New seals, guides, passing leak down test.
Portland Dave is offline   Reply With Quote
Old 09-13-2013, 10:04 PM   #10
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default

Well, yes these are interference engines and yes the pistons did hit the intake valves on all cylinders. No use screwing with it so back to the shop for the heads.
Portland Dave is offline   Reply With Quote
Old 09-15-2013, 11:21 AM   #11
kellygnsd
Scooby Guru
 
Member#: 32669
Join Date: Feb 2003
Chapter/Region: SCIC
Location: Rancho C
Vehicle:
2007 2.34LR, EFR7670
LINK G4 hybrid STi

Default

That sucks dude. Did you not have a shop manual handy when you set the timing? I could forward you a copy of the procedure if you don't have it.
kellygnsd is online now   Reply With Quote
Old 09-15-2013, 10:52 PM   #12
Portland Dave
Scooby Newbie
 
Member#: 59891
Join Date: Apr 2004
Default

Thanks, but I do have a manual and stupidly got the marks wrong cause I wasn't paying close attention. The manual really stresses on how to properly move the cams when attaching the belt but has a one liner for the crank markings. Any suggestions on good replacement valves?
Portland Dave 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 Off
Forum Jump


All times are GMT -4. The time now is 11:12 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.