Broken Tensioner Bolt

[06SubLegTx]

Okay, it's a 2006 Legacy 2.5i Limited.  I have owned this car for about a month and half or so. It has 99,500 on it. 

 

Today I am driving and the engine loses power/stalls, I try to restart it, with no luck.

 

I get the car home and want to make sure the timing belt was moving properly. When I remove the small part (driver side) I see metal shavings. I could press the timing belt down at least a 1/2" and I know that not good. I was honestly feeling a little sick/kind of depressed.  I let the engine get cold before draining the antifreeze. Remove all the stuff (belts, alternator, harmonic balancer etc) 

 

I take the remaining bolts out of the timing belt cover, and there it is, the Timing Belt Tensioner bolt had sheared off.... the tensioner was just floating it its area kind of...

 

I know the timing had to have moved, if you see the picture with the belt, the clip is to show you where it was...

 

According to Carfax the car had a cam seal(s) installed and Timing belt tensioner & Idler check on 10/10/16 @ 96,764 miles at a NON Subaru repair place in Round Rock, TX... I won't say who YET but they should have seen the tensioner leaking, and they of course didn't.

 

Now what to do next... I don't want a junkyard engine because - You get someone else issue.

 

Thoughts

 

[GeneralDisorder]

Yep. They over torqued the mounting bolt. Seen it MANY times. They caused the tensioner failure by improperly compressing it and then over torqued the mounting bolt.

 

Line up the crank to its timing mark (line on rear trigger point, crankshaft key at 6 o-clock) and see how many teeth the cams are off.

 

Most likely it's going to have a lot of bent valves. You can just do head gaskets and replace the valves. They are cheap. You will need to heli-coil ALL the idler and tensioner mounting points and replace all the bolts.

 

GD

Edited April 11, 2017 by GeneralDisorder

[06SubLegTx]

Yep. They over torqued the mounting bolt. Seen it MANY times. They caused the tensioner failure by improperly compressing it and then over torqued the mounting bolt.

 

Line up the crank to its timing mark (line on rear trigger point, crankshaft key at 6 o-clock) and see how many teeth the cams are off.

 

Most likely it's going to have a lot of bent valves. You can just do head gaskets and replace the valves. They are cheap. You will need to heli-coil ALL the idler and tensioner mounting points and replace all the bolts.

 

GD

GD, I purchased all the stuff from Subaru, and was going to do it a week ago... should have listened to my intuition. Do you think I will be able to extract the old bolt out, and hope they didn't strip it?  Are heli-coils really that reliable? 

 

If I going to do all the valves I might as well measure the valve tappets (buckets) to?, Head Gaskets Bolts?

 

Have you ever heard of this being done?  Inserts

[1 Lucky Texan]

GD - could he do leak down tests as-is?

 

 

anyway, if the engine was running when a car was rear-ended, it should be OK.  But, rebuilding one or both of your heads is probably cheaper than an engine purchase and swap....dunno.

[06SubLegTx]

GD - could he do leak down tests as-is?

 

 

anyway, if the engine was running when a car was rear-ended, it should be OK.  But, rebuilding one or both of your heads is probably cheaper than an engine purchase and swap....dunno.

Thanks, That is what I was thinking....

[GeneralDisorder]

You don't need deck plating till you are pushing over ~25 psi boost..... you have a non turbo with cast pistons and nearly 10:1 compression. Not happening. Besides, it's the wrong block. You start with ano EJ255 or EJ257 for deck plating. Which, by the way, is a mediocre solution vs Darton sleeves.... but that's a whole different discussion for a different forum.

 

Heli-Coil's are much stronger than the aluminum. Most racers heli-coil every hole on their aluminum blocks and heads prior to assembly to facilitate disassembly.... because race car.

 

Single cam engine have adjustable rockers, not buckets. And yes replacing the valves will require reseting the lash.

 

GD

[06SubLegTx]

You don't need deck plating till you are pushing over ~25 psi boost..... you have a non turbo with cast pistons and nearly 10:1 compression. Not happening. Besides, it's the wrong block. You start with ano EJ255 or EJ257 for deck plating. Which, by the way, is a mediocre solution vs Darton sleeves.... but that's a whole different discussion for a different forum.

 

Heli-Coil's are much stronger than the aluminum. Most racers heli-coil every hole on their aluminum blocks and heads prior to assembly to facilitate disassembly.... because race car.

 

Single cam engine have adjustable rockers, not buckets. And yes replacing the valves will require resetting the lash.

 

GD

GD, thanks a bunch.... I'm going to just pull the engine since I think I will have bent valves.... that way I can get the broken bolt out with better access

[GeneralDisorder]

Well the broken bolt is on a plate that unbolts from the block and fits in your hand. So you don't really need to do that.....

 

GD

[06SubLegTx]

Well the broken bolt is on a plate that unbolts from the block and fits in your hand. So you don't really need to do that.....

 

GD

I'm worried about the portion of bolt that is in the hole where the Tensioner mounts to..

 

I'm hoping that when the person who used a impact wrench or had the incorrect torque specs  didn't crank it down really hard, so when I drill it out, and use a easy out, that it will come out without any more damage. 

[DaveT]

I've heard of many disasters with easyouts... Probably better to use a left hand drill. If it doesn't come out while drilling, easy out is a big risk of getting a piece of hardened steel stuck in the bolt. I'd wait util someone can confirm this.

[1 Lucky Texan]

gd is telling you you can buy a new mount for the tensioner - no hassle and no helicoil.

 

gd - isn't there even a design change on the mount - if I recall correctly, it's an upgrade. (or maybe that's only on turbo engines, something about the steel insert the hydraulic pin rides against?)

 

 

anyway - it's number 9 is this diagram (part # 13156AA052 I THINK, confirm before purchase)

 

 

Edited April 11, 2017 by 1 Lucky Texan

[06SubLegTx]

gd is telling you you can buy a new mount for the tensioner - no hassle and no helicoil.

 

gd - isn't there even a design change on the mount - if I recall correctly, it's an upgrade. (or maybe that's only on turbo engines, something about the steel insert the hydraulic pin rides against?)

 

 

anyway - it's number 9 is this diagram (part # 13156AA052 I THINK, confirm before purchase)

 

 

Lucky, and everyone else thanks for the comments.

 

Lucky, the Part # 9 is correct...and it was my lucky day, I went to Subaru today, and while speaking with the parts guy, and a mechanic. I showed them my image of the broken part. They said they could help me. They had a engine replacement job almost done and the engine coming out was junk, so we compared part number, and the one I needed was on the junk engine, and in perfect shape..... they gave me the part for FREE...these guys are AWESOME.

 

I'm going to pull the engine out anyway to inspect and replace what is needed, Front / Rear Crank Oil Seals, Cam Seals, Oil Pan Seal, Oil Pan Pickup (I have heard they can break),  Anything wrong with the heads, new head bolts, gasket/seals and new guides and valves if needed...

 

Thoughts? am I missing anything?

 

Again, thanks to everyone here

[1 Lucky Texan]

wow - what dealership/shop was that ?

 

you may be making this a bigger project that needed. nothing wrong with that if you want a project.

 

front crank and cam seals are often, not always, changed at timing belt service. If they look dry, you could wait on that. never read of rear seal change as a PM - and although I understand on the oil pickup, I dunno if it's worth doing if you aren't into the pan for other reasons. Let us know how that goes. Kinda want a Killer B on my WRX, but, I'm afraid I would introduce a leak from the pan as I have no experience with modern sealant use.

 

if you pull the heads, it's my understanding the bolts are re-used. But, new cam cover gaskets would be a great idea.

 

kinda out of my element so, maybe gd or others can advise you better.

Edited April 11, 2017 by 1 Lucky Texan

[GeneralDisorder]

Head bolts are reused. DO NOT touch the crank seals, cam seals, or valve stem seals - they are Viton and are good for the life of the engine. Just put in new valves, set your lash, and put the heads back on. 

 

You don't need a pickup. That happens on 300 HP STi's, not the non turbo engines.

 

1LT - the pickup is easy. Use the new 3 Bond 1217H. Get it from the Nissan dealer. Much cheaper.

 

GD

[idosubaru]

1. I didn't read every word here - but it's possible to have a failure and no bent valves.  It's of course rare, but if you're the lucky person who had a complete failure and the valves settled without colliding you could get out of this with just a new timing belt, tensioner, and pulleys. 

 

install the new belt and tensioner and pulleys and do a leak down test.  or you could try to start it.  you don't even need to install the timing covers, crank pulley, and drive belts - just leave it all naked and do the test immediately after installing the timing belt.  it's hardly any work at all to test it and properly diagnose before moving forward. 

 

2.  If you repair - new Subaru headgaskets, new valves, resurface the heads, new timing belt, tensioner, and pulleys. 

[GeneralDisorder]

You don't need a leak down test. Just pull the valve covers and check the lash. Much quicker.

 

GD

[06SubLegTx]

I won't be able to removed the engine until this weekend.

I have to get an Engine Hoist and stand tomorrow.

After the engine is out, I am going to take off the heads for two reasons.

1. The passenger side is the original head gasket and I want to inspect it to be safe.  

2. The driver side has a newer head (looks like new head and that was not on the carfax report) I'am curious and I want to inspect it.

 

Since the engine is out I putting all new Subaru Seals (Both Cam Seal, Crank (Front & Rear), Oil Separator Cover & Hardware  (FYI- I have all the proper tools to install the seals in and I planned for this) just didn't think it would be this soon.

It's also getting new (Subaru Only) Thermostat, Temperature Sensor Sending Unit, Oil Pressure Sending Unit, PVC, Crank Sensor

 

Again, thanks everyone, and if you have thoughts I am open to them..

Mike

Edited April 15, 2017 by 06SubLegTx

[GeneralDisorder]

Don't touch the rear main seal, front main seal, or the cam seals. They are Viton and will last the life of the engine. Trust me - you'll potentially create more problems. People routinely get the rear mains installed incorrectly and they leak. If you don't touch them they will be fine.

 

GD

[06SubLegTx]

Don't touch the rear main seal, front main seal, or the cam seals. They are Viton and will last the life of the engine. Trust me - you'll potentially create more problems. People routinely get the rear mains installed incorrectly and they leak. If you don't touch them they will be fine.

 

GD

Okay, I have them case I have a bet valve etc, then I will have to. There is a machine shop in Ft Worth that specializes in Subaru, Volvo, Honda, VW and Harley Davidson engines. They do great work.

[GeneralDisorder]

Actually you will not need to replace them if you have a bent valve. The valves can be removed easily without removing the camshafts.

 

You don't need a machine shop for this. Just lap the new valves in and reset the lash. Can easily be done in an hour with a suction cup lapping handle, and a valve compressor.

 

This is the BEST valve tool we have ever used:

 

http://www.toyotool.com/index.html

 

GD

Edited April 13, 2017 by GeneralDisorder

[06SubLegTx]

Actually you will not need to replace them if you have a bent valve. The valves can be removed easily without removing the camshafts.

 

You don't need a machine shop for this. Just lap the new valves in and reset the lash. Can easily be done in an hour with a suction cup lapping handle, and a valve compressor.

 

This is the BEST valve tool we have ever used:

 

http://www.toyotool.com/index.html

 

GD

Which tool is it?

[1 Lucky Texan]

Okay, I have them case I have a bet valve etc, then I will have to. There is a machine shop in Ft Worth that specializes in Subaru, Volvo, Honda, VW and Harley Davidson engines. They do great work.

 

 

what shop?

 

yeah,  the rear main seal 'almost' never leaks - I think in years of reading across several subaru forums, I read of ONE leaking, and it may have been previously replaced. Inspecting the air-oil cover is a good idea, though,the problematic ones were the old plastic covers.

 

gd - are there spots on the crossover pipe he should look at? basically, where would you want to get your eyes to check o-rings/seals and for rust, etc.? what are the 'gotchas' to be careful about over or under torqueing?

[06SubLegTx]

what shop?

 

yeah,  the rear main seal 'almost' never leaks - I think in years of reading across several subaru forums, I read of ONE leaking, and it may have been previously replaced. Inspecting the air-oil cover is a good idea, though,the problematic ones were the old plastic covers.

 

gd - are there spots on the crossover pipe he should look at? basically, where would you want to get your eyes to check o-rings/seals and for rust, etc.? what are the 'gotchas' to be careful about over or under torquing?

1 Lucky, do you know of a good shop in Dallas, Ft Worth area?

[1 Lucky Texan]

1 Lucky, do you know of a good shop in Dallas, Ft Worth area?

 

 

I wish,... that's what I was asking you about.

 

I had to have 2nd gear/rebuild fixed in my WRX's trans - AWD Tuning in Flower Mound did it. But it's quite far from where I live. I think they were VERY fair with the price, just kinda slow getting it done.  Everything else I've done myself so far but, I really can't get deep into it and my age, lack of experience and lack of a 'helper', makes it more difficult to do 'heavy' wrenching. I recently had an air bag recall done (cost me $0 and I got a loaner) on the Outback at the new Sam Pack dealership in Grapevine - but their labor rate is $135/hr !!! It's an option but, pricey and still a longer drive than ideal.  Dunno what I'm gonna do when I need a clutch.  I might try MP Auto in Pantego - they've helped my daughter a lot and have good reviews - but I dunno how Subaru-experienced they are.  I guess a clutch change shouldn't be tricky for them.  If I needed an auto machine shop, guess I'd call Arlington Automotive Machine first and have a conversation, I just haven't needed that, yet.

Edited April 14, 2017 by 1 Lucky Texan

[GeneralDisorder]

gd - are there spots on the crossover pipe he should look at? basically, where would you want to get your eyes to check o-rings/seals and for rust, etc.? what are the 'gotchas' to be careful about over or under torqueing?

 

 

Not a bad idea to replace the coolant cross over pipe o-rings. Careful with the 6mm bolts they like to snap off if you have a corroded block. 

 

Pretty much any of the 6mm stuff like the water pump bolts like to strip out if someone has over torqued them in the past. 

 

One of my tech's insists on using an inch pounds torque wrench on the 6's, 8's, and 10's holding the idlers, etc. I don't personally, but it's up to how comfortable you are. We end up doing thread repair a LOT. Have had to do all the water pump bolts and all the coolant cross pipe bolts on a block more than once. 

 

Broken tensioner bolt is sure sign of ham fisted tool operator. Check all bolts for stretch, and all threads for damage. Probably best to heli-coil ALL the holes if any of them are suspect or stripped. It's cheap insurance really. 

 

GD