2012 Outback Timing Belt Question

[Banjo1928]

New to this Forum but have had several Subaru's over the years. Yesterday I decided to replace the timing belt on my wife’s 2012 Outback.  The car has over 120,000 miles on it so I figured it was time.  I couldn't remove the bolt in the crank pulley, tried several times to place 8mm pins in two of the holes and wedged a pry bar in there and just could not budge the bolt.  I decided to order a tool to hold the pulley and just put it back together and wait.  So it wouldn’t be a total loss I changed the oil, put new plugs in it.  Went to fire it up and it would crank just fine but not start.  I checked and rechecked everything nothing lose all electrical connected. I had disconnected the battery so the car had no power for maybe 24 hours or so.

 

Now here’s the thing. During my little adventure when I was turning the engine over with a breaker bar on the crank pulley I turned the engine the other way (backwards) and by that I mean as if I was tightening the bolt and as I did it there was a popping noise.  I thought I’d pushed the pins into the crank pulley too far and they were dragging on the plastic timing belt cover behind the crank pulley.  Now I’m thinking maybe you can’t turn the motor on a 2012 Outback backwards and maybe the popping noise I heard was the timing belt jumping off the crank gear pushing the thing so far out of time it won’t start which then brings the 2,000 dollar question could I have got it so far out of time I damaged the valves?  I’m actually sick to my stomach thinking about this.  At first I thought maybe I used the wrong plugs or maybe some security system was wiped by having the battery disconnected for so long.

 

I’m an old shade tree mechanic and probably had no business trying to replace a timing belt on a 2012 automobile but I figured it’s a mechanical job not electronic just nuts and bolts.  It never occurred to me you could only rotate the engine forward by hand.  Hopefully it’s something else but I had to get up the courage to ask.  Sorry this post is so long but
I’d be interested in anyone’s thoughts on this.

[nipper]

You stopped at the noise?

 

The timing belt may have jumped. You (hopefully) shouldnt have opened the valves far enough for them to make contact with each other.

[Banjo1928]

Well, I er um, I heard the noise, thought it was just the pins I put in dragging on the plastic, heard the noise again, okay okay I may have heard it four times I'm such an idiot. So if you try and turn the motor backwards bad things happen? Everyone knows that but me, if I could have found a manual it would have said WARNING DON'T BE AN IDIOT AND TURN THE MOTOR BACKWARDS don't cross the streams Venkman.  Thanks nipper

[nipper]

Dont beat yourself up. If the valves hit each other it would have stopped you mechanically. 

[idosubaru]

backwards doesn't matter - you can turn a Subaru motor "backwards" all day long - it doesn't "know" what forward and backward are - it's just a bunch of pistons moving "up and down", it doesn't care about direction mechanically speaking.

 

that being said - yes you can totally turn the crank enough to slip teeth (not just backward but forward too).  if it slipped teeth while turning backward, it would have done the same thing turning it forward (tigthening).  

 

i'm confused by what you mean "pins" - if you turned the engine "backward" - then the engine should just rotate.  but what did you do to stop it from turning?

 

what most people do is just stick a long stout screw driver or socket extension into the rear bellhousing access hole under the throttle body on the back of the engine.  you can insert it into the flexplate there and prevent the engine from turning over that way.

[Banjo1928]

The holes in the crank pulley are smaller than most I have seen I found an old 1/4 inch extension that would fit in one but no other extension would fit. I measured the diameter of the one that fit and its shaft was 8mm so I took an old screw driver with an 8mm shaft and cut two pieces out of it (pins) and they fit nice and tight into two of the holes in the crank pulley. I then put a pry bar between them, wedged it against the center motor mount and cranked on the 22mm pulley bolt for all I was worth until it looked like I might be damaging the holes in the pulley where I'd place the pins and the bolt was starting to look a bit beat so I said I'll stop and get a proper tool to hold the pulley.

 

Now, I totally agree with you grossgary, the motor should not know or care. I watched a YouTube video and a guy did the job on a 2007 and he rotated stuff both directions no problem. But, on this 2012 when I was setting it up to find the perfect spot to brace the pry bar on and get the pins up tight against it I rotated the motor clockwise from my perspective looking at the bolt from the front and it made a pop or thump. I thought I'd pushed the pin into the hole on the crank pulley so far that it was dragging on the plastic timing belt cover. I moved it again and confessed to nipper in a PM that I moved it enough to hear that pop five times. The farthest thing from my mind was that I was making the belt skip on the gear. Turn the motor counter clockwise from my front perspective and the engine turns over no noise, turn it the other way and pop. Someone said with variable valve timing and water or oil pumps you can't turn em that way anymore. It makes on sense to me, crazy if you turn it the wrong way it jumps time.  I hope you are right, I really do because pulling heads and replacing valves is not going to be a lot of fun for me. Thanks for the response and any and all thoughts are appreciated.

[Banjo1928]

Received the crankshaft pulley holder and removed the crank bolt. It was definitely way off time thanks to me. As an experiment I took the old timing belt off put the new one on correctly then turned the motor both ways. I could not duplicate it jumping time. I spoke to a mechanic who works on Subarus and he did say if you spin it backwards it can jump but now that I have the timing cover off and can see everything it would not do it for me. The old belt looked good as did all the parts so I don't know how I managed it but I did.  nipper, you were correct I did not move it far enough out of time to bend the valves. Put it all back together no issues. I cranked it and it fired right up and ran so in spite of myself it appears I dodged that bullet. Thanks to all who helped me through this.

[Numbchux]

With any engine with a sprung tensioner, spinning things the other way can put slack in a different place on the belt that it can jump time. I don't think is new to a 2012, I've had it happen on an early '90s EJ22. It's rare, and requires the engine to be at just the right place in the stroke to keep the cams loaded against the valve spring in the right place.

 

 

Subarus with a manual transmission have a guide over the crank sprocket, and sometimes on a cam sprocket to help combat this (it's possible that a person might park the car with the engine off, and in gear, and have it roll backwards a hair and have this happen without taking anything apart).

Edited March 28, 2016 by Numbchux