Broken bolt in cylinder head 2.5 (Thank you Lord!)

[a97obw]

Well, the Haynes manual I could not find the torque specs for the camshaft bearing cap bolts for the Phase 1 2.5. However, the factory info is 14.5 ft. lbs which should be just about 174 in. lbs........which is where the #1 exhaust bearing cap on the top bolt decided to call it a day. Just at the point I'm about to stop and back it off, things broke loose. As in all the way loose. I put the torque wrench down and sat there for a minute. To my PLEASENT surprise, removing the bolt revealed the bolt had failed and not the aluminum head.

 

That I can deal with!

 

But I'm not so sure about this Harbor Freight Inch Pound 1/4 inch drive torque wrench........that I compared and verified with my 1/2" drive torque wrench at 14.5 ft. lbs before I started.

 

So either chock one up for Subaru designing the bolt to fail before the threads in the aluminum head or I got lucky. (I'll take either.)

[Olnick]

I put the torque wrench down and sat there for a minute.

 

Great line! I've done the exact same thing.

 

Sounds like you dodged a bullet there. Good luck.

[paulivan]

I'm having same problem on 2.5L DOHC. Shearing new bolts at 14.5 ft.lbs. What was your solution or did you continue with success at 14.5 ft.lbs. I'm backing off to 10 ft.lbs because I'm tired of extracting broken bolts...3 sheared.

 

PT

[a97obw]

I had no problem getting the larger bolts---the ones that fit the center and rear camshaft caps to the head---torqued to 14.5 ft. lbs which is what was specified by the few pages of the factory manual that a vendor was cool to send me. However, as for the smaller bolts that hold the front camshaft caps---the ones with the seals----I think I had one of them go to 14.5, then the next one broke as I metioned in this initial message board thread. I broke all of those loose again and ordered 8 new bolts for the front camshaft caps, then went back and reinstalled everything, stopping short of the 14.5 for the front ones---probably 10 or 11 I would guess.

 

Check the Haynes manual for the specs.---I did find the specs for the 2.2 engine and I seem to remember 120-144 in. lbs which would be 10-12 ft. lbs.; if you are using a ft. lb. torque wrench this is probably right at the bottom of the specs for the wrench, but about the middle of a smaller 1/4 inch drive in. lb. wrench.

 

I put each bolt back in the same hole it was originally in, and before fitting it all together I blasted each hole with carb cleaner, then WD 40 and trial threaded the bolts to make sure they threaded easy. When I finally installed them, I put just a shot of WD 40 on the bolts and then tightened them as per the pattern several times just a bit mo' snug ( I can say that!) before reaching the final torque values. Hope this helps!