Ok, This week I plan to pull the top and adjust the valves as I seem to have loss some power. here is a little feedback on this.

Last month it seems I was losing a little ump on the get up and go... so I thought Id change the spark plugs and air filter. Well the #1 coil pack bolt was tight all the way out so I took it slow, the intitial loosening was super tight, it cracked and just super tight all the way out. So moving to #2 It too was super tight ( and I got some upper body strength too ) so it finally cracked loose ( which I though and caused my socket to fly off ) found the socket and went to get the bolt out, couldn't find the head....hmmm (feeling around) so I get a light and lo n behold..... it snapped off, pulled the coil pack and wouldn't luck have it, snapped flush even with the surface. So I go buy an angle drill and pull out my extractor set.. drilled the pilot hole then size it, the extractor wasn't budging it. I was afraid...SNAP ! well shit, so I jig around with it and get that one out ( hardened steel, cant drill em ) so I drill it out bigger, still the extractor wont budge it. SO, I just drill the whole bolt out. Bought a couple bolts and nuts and put the coil pack back on, returned the plugs.

Fast forward to today. I'm going to pull everything and the coils will be exposed since 3 and 4 were in assessable to do anything as why I didn't attempt it before. Now with the cover and all the stuff out of the way if the bolt snaps I can just drill them out. Just wondering if anyone else had to do this?
I thought of taking it to the dealer but I don't want them to snap one and say I need a whole new head or something. Any advice? Ive used PB blaster, WD40 and other penetrants to try and loosen these bolts but still tight and I left them alone... only for a few more days until I tear it down.

 

Man...sorry for your troubles. That does NOT sound fun!

I've always used PB Blaster and had good success, but I guess that isn't working here. A good friend of mine swears by Kroil. I've never tried it, but I trust his advise.

Another thing I'd give a try is putting a 1/4" socket extension on the head and hitting the extension with a hammer. See if you can jar it enough to loosen it some. Not trying to turn it. Just a dead smack on top of the head. Amazing how much a tap with a hammer can help.

Can also try doing it with the engine hot. Just be careful so you don't get burned.

 

With the engine hot spray the bolt head with circuit chiller then gently try and turn the bolt out with a SMALL wrench.. Sometimes chilling the bolt on the warm motor will allow the bolt to shrink enough to break loose.

 

The bolts are threaded into through holes. The penetrating mix ( kerosene, acetone and ATF) has to be applied from the bottom side (easier said than done!) to the warm (30-35 Degree C) engine (place rag on the heat shield /exhaust manifold during application!) than drive car for a short trip. Repeat this application few times. I used this method to remove stuck O2 sensor from cast iron manifold on full size GM car and it worked.

 

Yes I tried both of those methods, chilling the bolt and getting penetrant from underside to the threads hoping it will help. I did it before and left it after the #3&4 wouldn't budge, added some recently in hopes it worked into the threads before I attempt it again maybe tomorrow. I really don't look forward to the headache but have to start somewhere right....lol

 

Also invest in 11/32 or 3/16 left hand cobalt drill bit (it is not that expensive) for drilling out the broken part of the screw. The key point is to guide it correctly. I never saw or used this method on "in car" engine, however a drilling jig made from 5/8 by 3/4 steel bar containing 4 3/16" dia holes (which are counter bored to 6 mm dia over 5/16" length (to accommodate for sticking screw stumps) can be used for this job (it can be kept on the engine by adding two round cylinders 3/4 inch long (machined from plastic such as Delrin) which will fit into the spark plug wells let say on 1 and 4 cylinders).
So , remove intake plenum
next,drill the heads on the remaining bolts using 1/4" bit and remove the coils.
after that, drop the jig in place
then drill the bolts out while holding jig in place with your hand (I wish I would have an angle drill.)
At least this method will save threads on the head

 

I used an automatic center punch on the one that broke with the reverse drill, went all the way through the bolt and it was still in there, tried a larger extractor and it still wouldn't budge so I just drilled it out and used a bolt with a nut. I didn't get to work on it today, raining today and tomorrow ( no garage) so probly next weekend?

 

I'm not sure what the maintenance history has been on the car, but I read similar posts from owners on other forums too. I feel so badly for you Sono. I suffered a broken bolt on my truck and its extraction was a failed mess.

I can't understand why people don't read tightening specifications, nor use a torque wrench nor anti-seize as they work. They could save themselves and others a lot of grief.

Gen2 coil pack bolts are to be tightened to only 6 FT/LB (72 IN/LB) and that's probably a match to yours. Sigh.

I wish you success with your work.

 

On my Fit I tried 12 point socket and noticing that it was about to round the screw head, so I promptly switched to 6 point one and finished the job.
I can speculate that trough hole exposes entire thread to environment causing aluminum to corrode and jam the lower portion of the threads

 

Yea, the Coil pack bolts likely would benefit form some anti seize.. Steel in to aluminum is always dicey..

 

To me it seemed someone used locktight on the threads, but then again everything under the hood looks 100% original.

 

Ive broke intake bolts off in the heads of my truck, luckily I was able to extract them but yes, it is a PITA to begin with. I am having second thoughts to just bite the bullet and let the dealer mess with it... but then again, Id rather save that money BUT if it does snap, I'm back to square one...lol

 

Apply mix twice a day for one week; it should be able to finally free the threads.