15 June 2014

Booooo! Well, I guess I should be happy that the car ran great… last week. This week she’s back to being fussy, with not one, not two, but three failures in a single drive!

So I’m cruising down the coast highway, and at one point sped up briefly around slow traffic, and idle suddenly wouldn’t drop below 2300 rpm. Ugh, okay, that’s happened before, when the “push-lock” MAP reference line popped out of the throttle body. Since I was practically at my mom’s house I kept going, and about a minute later heard the alternator belt squealing… huh? That hasn’t happened since that bolt broke… couldn’t be that. Then while heading up the last street, I saw coolant trailing behind my car… seriously?

Yes, seriously… three failures.

Cutting to the chase: The alternator bolt broke – again. Grrrrr. The MAP reference hose had indeed popped out, and did so twice more on the way home. A silicon coolant bleed line “cracked” – the only way to describe the failure… Ugh, like I said, at least it ran great last week when it mattered.

The solutions:
1. The coolant bleed line – easy fix.
2. The MAP reference line – I’ve had enough of the push-and-lock fittings, they’re all coming out of the car.
3. The alternator is the bitch. The manufacturer has a fundamental problem which I now get to fix, since their supposed Honda bolt solution was apparently an excuse to cover up a defective design, one which causes the alternator to resonate at a certain rpm and start shaking – what else can break a bolt half way down its threads?

There are two possible fixes. One is to fabricate a separate mount assembly which picks up additional bolts on the block, making the overall mount stiffer and moving the resonant rpm higher, hopefully above the engine’s operating range. One guy had written me the first time that this happened and said he had the exact same thing happen several times. He even drilled out the block, Helicoiled in a massive grade 8 1/2″ bolt, and it still broke. He finally solved it by fabricating a secondary mount so that the alternator couldn’t wobble.

The other possible solution – maybe – is to leave the bolt out entirely. There are already two large bolts along the bottom, and if something like a Delrin spacer is installed where the aluminum one was, and the belt tensioned, it would compress the spacer and trap the alternator. I’ll have to think it through to decide if it’s a viable design. Having no bolt most certainly shifts the resonance point, very likely to a lower rpm, maybe even below the engine’s operating range. In any case, the good thing is that it’s easy to test since it’s rpm-related instead of load-related, so I can watch it while revving the engine. I’ll have to think it through a bit more…

And then there are the other goodies… more about that after the above is delt with.