Just replaced timing belt on my 98 Outback and now idles rough. Now I'm worried...

[cheetah8799]

Greetings everyone. I'm new here, but have owned my 98 Legacy Outback (w/ 2.5l engine and 5sp manual) for about 4 years now. This may be a long story, but I really could use some advice from other Subaru owners and mechanics.

 

A few days ago I finally took apart my Outback to fix an oil pump seal leak that I've had for almost 2 years now. It's the main seal on the crank shaft that goes throught the oil pump. Apparently this is a common problem with the Subaru 2.5l engines. While I was at it I decided to replace the timing belt as well since I had to take it off anyway. The car has 109k on it.

 

Prior to doing this, I copied the Chilton's manual pages relating to timing belt installation and removal for my engine.

 

So I went at it. No problems til I took off the belt. Chilton's didn't warn me that the left side camshaft sprockets were under tension and would spring free when I removed the belt! I now have a document from engwrench.com that shows the proper tools to hold them in place, but hindsight is 20/20. They sprung, but didn't rotate super far, so I think we were able to line them back up by hand later, they may have damaged the valves though...

 

So by now my dad arrived to help. He wasn't too worried (i was...). We replaced the oil pump seals and started work on installing the new belt. We lined up the TDC on the right side camshaft sprockets without any trouble, they weren't under tension. The left side ones were, so when we go to putting the belt over them, my dad used a socket wrench to rotate and hold them in place while I seated the belt.

 

We got the belt seated, and installed the idlers and such. At this point everything was lined up. We double and triple checked everything. The only problem though was that the double-notched markes on the right camshaft sprockets were a tad off. Not a whole tooth, but a little. Apparently from what I've read, this means the engine is a little off, but it can't be fixed.

 

So we put it all back together, but now for the bad part that really has me worried.

 

The engine now idles really low. No strange noises, but really low, and it putters a little coming out of the muffler. It also idles rough, so when I sit in the car I can feel the puttering. Same frequency as the exhaust puttering. When I apply gas and put it in gear the car runs great. I've driven the car about 40 to 60 miles since doing the work, and no warning lights or anything have come on.

 

SO! Now what? I'm thinking the engine needs to be timed, and I have a timing light, and know how to hook it up, but not sure what to do next. I can't find any documentation on exactly how to do this. I also am not sure if I messed up the valves. From what I've read, it's really easy to do on this engine... I suppose that could account for the puttering if it is firing wrong, but I'm not sure.

 

If anyone here can help, I'd really appreciate some advice right about now. Before I freak out any more...

 

Thanks.

-Josh

[subiemech85]

IF there is a coil pack, then there is a "set timing" procedure, usually involves messing with a wire

 

IF you disconnected the battery, the car might have to "re-learn" how to run correctly

 

I'm NOT experienced with NEW GEN SUBARU

[lmdew]

I'd pull it back apart and re-check the timing. I've done a few of these and even with triple checking, its not hard to get one of the 5 gears off just a tooth. Also, when the tensioner takes up the slack, it may repoistion things some.

 

Did you get the belt with the timing marks painted on it? Make sure you're on the correct crank gear timing mark and its alignment is correct.

 

Look twice.....

[cheetah8799]

I'd pull it back apart and re-check the timing. I've done a few of these and even with triple checking, its not hard to get one of the 5 gears off just a tooth. Also, when the tensioner takes up the slack, it may repoistion things some.

 

Did you get the belt with the timing marks painted on it? Make sure you're on the correct crank gear timing mark and its alignment is correct.

 

Look twice.....

yep, it had the marks on it. We actually got those lined up the first try.

 

As for looking twice, well, how does 3 or 4 times sound? I think our big problem though is that we may not have turned the engine by hand enough to get it to move stuff around, just in case.

 

I'll take off the covers tomorrow and see what it looks like.

 

-Josh

[theotherskip]

check that you reconnected the air intake hose between the IAC (idle air controller) and the main hose connecting the air filter to the large plastic chamber before the throttle body. there are a couple of connections along the bottom of the hose that are easy to miss, and they can cause a bad idle if they are not connected...

 

hope that solves it...

[Adnan]

Hi,

 

I'm not convinced that the engine can be a bit off and that's okay. Since cam and crank gears are keyed, that's highly unlikely. Did you compress the tensioner using a vise and locking pin? Perhaps it hasn't extended all the way as yet and is allowing more slack than it should have.

 

I recall that when I did my '96's belt, I didn't notice the painted marks and put the belt on backwards. Strangely enough, the timing marks were just a hair off which suggests that the teeth have a slight angle to them. Make sure yours is on the right way (sounds like it must be if the painted marks line up).

 

Good luck, and by the way, I also had my left cams spin on me. Didn't seem to hurt anything, as she ran just fine.

 

Regards,

Adnan

[cheetah8799]

Hey guys, guess what! I got the rough puttering idle taken care of!

 

I opened it back up and looked at the timing. When everything else was lined up, the lower left (when facing) was off by 1 tooth counterclockwise. So I rotated it clockwise one tooth. I was able to do it because the belt was just barely loose enough all around to get it to rotate under the tension.

 

Anyway, I started it up, and it was smooth! I put it all together and drove around the block a few times to make sure. Every time I stopped to check, the puttering was gone, and it idled smooth!

 

I'm going to take it for a drive to the store and see how it goes for a longer distance.

 

 

As for the slow idle though, it's still idling around 400rpm. It's supposed to be 600 - 800, so I'll have to maybe figure that out still.

[Adnan]

Hi,

 

Glad to hear you found the problem. The belt should not be loose enough for you to rotate the pulley one tooth, sounds like the tensioner isn't applying the correct pressure. You may want to check into that.

 

Do you think you may have a vacuum leak? Did you disconnect anything related to the induction system? That might be the cause of the low idle, particularly if it runs fine at higher RPM. Check for leaks downstream of the mass flow sensor or any loose or soft hose connections. You may have bumped a marginal hose and not realized it.

 

Regards,

Adnan

[cheetah8799]

Adnan, I agree, the belt was a little more loose than I thought it should have been. It was really tight trying to get it on, but now it's loose. weird.

 

It wasn't loose loose though, still on pretty solid, and to actually rotate the sprocket I had to use a 10 - 12" wrench and crank on it kinda hard.

 

 

I'll take a look for any hoses or anything that may be old/soft/disconnected. I made sure to put everything back on that I took off, but you never know... especially with rookie mechanics like myself.

[Adnan]

Hi,

 

Just had a nasty thought - is it possible that your belt jumped when you first cranked and started the engine?

 

You mentioned that you had multi-checked the alignment and one would have little reason to suspect that you missed one wheel. Given that the belt feels loose now, it may have jumped on you. That would be an undesirable thing, to say the least, as it may do it again.

 

Something doesn't feel right about this. Did the tensioner feel okay? Did you install the belt around the pulleys in the right sequence? Did you spin all the idlers to see if they were smooth and not binding (as idlers do need replacement, sometimes)? I'd urge you to keep a close watch on this as the last thing you want is a bent valve.

 

Regards,

Adnan

[cheetah8799]

Well, when we installed the new belt, it was really tight to get on there. From what I'd read in the Chilton's manual, the way to do it was to get the belt on, then install the final idler pulley. We did that, and getting the last idler pulley on was really tough because of the tightness of the belt. When I released the tensioner, it did put more pressure on the belt.

 

 

Regarding the tensioner. Chilton's said to compress it in a vise to get the hydraulic piston to go back inside. I did it, and very slowly as the instructions said. I used a small allen wrench to act as a pin, and it held ok. And when released, it the piston did come back out. The Subaru documentation I've read from endwrench.com says to NOT use a vise, and that a special hydraulic vise is required to re-insert the pin, and that doing it any other way will damage the tensioner. I'm not sure how much of that is fact or not, but it's possible I suppose.

 

Is it likely that the tensioner is messed up?

 

 

Another thing to note is that when I first started working on this project, I was trying to locate the oil leak. I removed both side covers, and only the bottom of the middle cover. That's when I found that the oil was leaking from the oil pump seal on the crankshaft. To see that, I had to use my fingers to bend the belt up and out of the way a little. Not in a damaging way, just to get it to move a little. I don't think it was really any tighter or looser than what it is like now. I could be mistaken though, hard to say for sure.

 

 

I guess the thing for me to do now is to take apart the housing again and look at the timing. If it is off, then I know something is moving that shouldn't be...

[Adnan]

Hi,

 

Using a vise ought not to damage the tensioner, if done slowly. However, the Haynes manual does say that the piston should not be pushed in past the locking pin hole or damage could result.

 

I find it surprising that you could bend the belt up a little even. Is this a genuine Subaru belt or an aftermarket one? Were the idlers in good shape? Also, to my previous question, is the belt on the right way around?

 

One thing with that crank oil seal leak is that oil gets on the timimg belt eventually and then gets flung all around. Did you wipe down all the gears and idlers with alcohol to thoroughly degrease them? If not, the new belt could also be contaminated.

 

Boy, I'm out of ideas. And you still have the mystery of the low idle. There is absolutely nothing that could affect the idle RPM in this procedure other than the intake air tract. You sure all of that went in nice and tight? One thing to try is to find the wires going to the idle control motor (IAC) and see if disconnecting it makes any difference to the idle. If not, you may have a bad IAC or bad wiring, just a coincidence.

 

This will prepare you for the next fun task that is most likely headed your way - replacing the valve cover gaskets on both banks. The right side is easy, the left will leave you cursing and tearing your hair out at times.

 

Keep us apprised on what you find. Sorry I couldn't be more help.

 

Regards,

Adnan

[cheetah8799]

Adnan, thanks for all the great assistance. All the suggestions here are way more than I could have come up on my own.

 

The belt is a genuine Subaru belt, and yep, it's on the right direction.

 

The original oil leak was very minor, and only dripped very slowly down the oil pump housing. I'd be suprised if much got splashed around like you described. I didn't look too hard though.

 

I think my immediate concern now is the belt tension. In a week or so I'll open it up to check the belt and see what it's like in there. I'll try to get into the tensioner and see if it's tight like it should be. I don't want to tear off the whole pulley and stuff, so hopefully I can just get in enough by pulling back the top of the central housing piece.... i hope....

 

The low idle isn't a critical issue at the moment I guess. I'll check the areas you suggested though, just to see. I did test today the air conditioning, since when on it should raise the RPMs to 700 - 900 I believe. According to my tac, it did go up to around 600 - 700 I suppose. Not as high as it should be, but a definate increase. That's a good sign.