What was the temperature of the motor when you made this attempt?

Mileage?

Location? Coastal?

 

This is actually very likely what the issue was.

The motor has ~120,000 on it and it's out of a Florida driven s2000 up until 2 years ago. I imagine the heat, salty air, and humidity has taken it's toll on the bolts and caused them to corrode as JFUSION said.. When I went to remove and replace the alternator, I had to use a floor jack handle as a breaker bar because the bolts just didn't want to budge.

 

But I guess you could say I have a cool souvenir now.

 

Put those on the wall!

 

It's not the torque that gave you the problem, it is a steal bolt going into an aluminum piece which causes galvanic corrosion. If massive amounts of toque were applied to those bolts, they'd just pull the threads out. Also, it might have been easier to just drill the heads off the bolts.

When you drill the head off, you can generally turn the rest out by hand:


FYI, salt does not stay suspended in air.

 

Crazy!

Personally I'd just replace the valve cover and the coil cover...everything shiny new.

 

Isnt this the reason they say in the DIY to use blunt impact to loosen them?? For example, hitting the allen key with a mallet.

 

"Galvanic corrosion. "

Yup. AKA: electrolysis across unlike metals. When you buy the new valve cover and spark plug cover PLEASE use some kind of durable grease (like Honda Moly Stuff) on the threads and head of the bolts. A light coat is all you need. Or anti-seize goop. Then, you will never have to post similarly painful photos, again.

In the future, if you have issues that may lead snapped bolts or rounded heads --- try warming up the car or applying local heat (with a heat gun or a hand torch). Then, tighten the nut ever so slightly by tapping the wrench, first. This helps to break the galvanic bond between the steel bolt and alloy threads. Hopefully, the crazy thing will come undone without major surgery.

My bet is the previous dude that took that cover off used US dimension allen head wrench. And slightly rounded the edges of the bolt. Then, your 5mm wrench wouldn't fit snuggly into the recess.

Good luck with the plugs!

 

That technique works very nicely on bolts that have been:

a.) torqued down to spec.
b.) non-corroded threads.

I tried that, neither were applicable in my case.


Trust me guys, I tried every trick in the book and this was more of like a last ditch effort. Not every s2000 is going to be like this one, but if anyone else ever finds themselves in the same situation, they'll know that it is okay just to cut the thing off. Might sacrifice a valve cover, but can't do much else.

 

I really feel the pain. Good luck getting those aluminum shavings out of the cover area. Not sure how you are going to do this, as they are not magnetic.

BTW... this electrolysis issue can be a fatal one. I had an old 1995 Honda CR500 dirt bike. Crazy-@ss HP. Like 52HP on a 221 pound bike (soaking wet). This year had a fatal flaw. The steel impeller of the water pump would react with the magnesium case and MELT the casting in the water pump. Leading to instant seizure. And since the water pump was cast into the main side case, you had to buy a whole new right case. Which was like $300. Plus, the cost of a new piston and sometimes new Nikasil bore cylinder head.

Good luck with the plugs. May the Force Be With You!