Did timing belt on ej25 engine. One of the timing idler bolt holes  (m10x1.25) is patially stripped. Whats the best solution to repair. Would a thread chaser be worth a try? Whats the best options after thread chaser. Helicoil, Time Cert, tap to next larger size. I know about, but have actually never done any of those methods.

Clean the threads with a chaser or tap and try a longer bolt. Often the threads are tapped further in than the stock bolt can reach.

Stick a small screwdriver into the hole to guage the depth, then find a bolt that's just a bit shorter than that.

 

If the longer bolt won't hold, a helicoil kit will work fine. Getting enough room to fit a drill in the car can sometimes be a challenge though.

As Fairtax stated, try chasing and add a longer bolt. I'd also recommend buying some red loc-tite (make sure bolt hole is clean and dry) and apply some to the bolt and it'll unlikely back out and you shouldn't need to crank it too tightly. 

 

In the future, if it's too tight too remove, add some heat to the bolt head and it should loosen.

 

In lieu of a heli coil, you could also try tapping the hole to the next size bolt as that's be a permanent solution, though you'd need to see if the tensioner's hole would need enlarged or not.

clean threads, try a longer bolt.  those big EJ bolts aren't terribly forgiving of that method though, make sure you can torque it tight enough.

 

drill and helicoil.  

 

a right angle drill is the best bet - some are low profile and fit in front of the engine..  i've rented one before.  you can dry a right angle drill attachment for a drill as well. 

 

put the drill bit in a vice and wail it as fast as you can with a hammer to shear if off.  while hard, drill bits are brittle and will shear with a fast enough blow.  that said - wear goggles and protect windows, or have it fly into a towel (hopefully) when that end shears off it'll bounce off every floor, wall, door, and ceiling in your garage.  gotta hit those bit bits pretty fast to shear off.

When I did my timing belt last weekend I stipped the top bolt on the water pump (2005 2.5i sohc)....I was pretty pissed because it wasnt even that much force!! 

 

Prob should have used a 1/4 inch drive socket!! haha

 

 

 

Anyhow I used a longer bolt and it worked for me also. Good advice from all 3 people that suggested it here. 

good job knocking out the water pump. definitely worth a shot nearly every time. the water pump bolts are much smaller, lower torque, short (so as a percentage the depth of the hole is much greater increase) - so those are nearly a 100% success rate. the bigger higher torque timing bolts might be a different story but hopefully it works for him, definitely worth a shot as it doesn't really cost anything.

Edited March 15, 201610 yr by grossgary

I just ordered a Mini Master Time Cert kit from Amazon.  Got $80 off for signing up for new credit card,so the cost was about the same as buying two helicoill kits. It comes with sixtiy m6, m8. and m10, inserts.There were two m10x1.25 stripped bolt holes on this engine. The second being the timing belt tensioner bolt. I get to learn a new skill with Time Cert.