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Old 12-08-2020, 11:54 AM   #53 (permalink)
Stubby79
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Join Date: Sep 2012
Location: Victoria, BC
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Firefly EV - '98 Pontiac Firefly EV
90 day: 107.65 mpg (US)

Little Boy Blue - '05 Toyota Echo
90 day: 33.35 mpg (US)

BlueZ - '19 Nissan 370Z Sport
90 day: 17.19 mpg (US)
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Quote:
Originally Posted by Stubby79 View Post

Of course, I haven't heard any pinging in the exhaust.
I take this back. Sort of. Just test drove it. There's a distinct growl and a rattle, any time under extreme load while under 2000rpm. It doesn't sound like marbles bounding around in my engine, though. I heard what sounded like the same rattle when I hit a small but sudden bump, so the rattle is just as likely to be from (not so good) engine vibrations making something else rattle. Dunno.

It happens regardless of if its extreme load while in lean-burn or if it's out of it, though the in-between - ie just after it goes out of lean burn but before you get the pedal down a lot farther, where it's not an extreme load for the throttle position - is fine.

I define "extreme load" as when the car is completely unable to accelerate, despite opening up the throttle more. Not usually a problem with typical gearing, but with the insight's tall gearing, it occurs easily. Typically gets worse the longer you stay in this state, though that could be the RPM's slowly dropping off. If it can pull out of it, it's not an issue. If you're over 2000rpm, it's never an issue. That makes it more pleasant to cruise over 60mph than it does at 55 and under.

She's definitely less stuttery. But it was after putting in some higher octane gas. It might be the same, it might be better after dicking around with the spark plugs. Hard to remember exactly what it was like a few days ago, after only a couple of trips with the higher octane in it. Whether or not it is, it's certainly no worse, which means I'll leave the spark plugs as is for now.

I put the new rotors on before going for a test drive:



I looked closely at the old rotors. Was looking for hairline cracks that I might have not noticed previously. Didn't find any. About the worst I found was this rash:



Might have been enough to have been doing it. If nothing it suggests that they're made of cheap metal, or at least cast on the cheap. Of course, it might not have been the rotor's fault, could have started as rust pitting, if the brake pads had sat there holding dampness against it for ages. But there is no impression of the brake pads there, while there still is elsewhere. Or some foreign material might have been ground in to the metal when braking hard. Who knows.

One would have hoped the sanding I did to them would have smoothed the edges of this rash and taken off the impressions left from where the brake pads sat for ages, but it obviously did not. A proper machining probably would have done it, though if it was the rotor itself at fault, it would have come back eventually. You have to look hard to find any of the swirl marks left from my sanding...plenty visible near the top in the pic, but for the most part, you could hardly tell.

The marks in the metal around the "drilled" spots appear to be more pitting/rash. More evidence to point at low quality metal and/or casting.

I didn't spend much on the new rotors, but they were one of the few on the "daily driver" quality from RockAuto. Heck they were cheaper than some of the econo-quality ones. But since they're not, I expect they will hold up a lot better than the old ones, and no drilling or slots in them to compound the likeliness of variations in the metal's quality.

I like the look for drilled rotors, but what's the point when the wheel completely covers them anyway? Not like I'm going to throw better looking wheels on it. The only thing I would consider are Civic VX/HX (whichever it is) ones. These are probably lighter still, and certainly more aerodynamic.

Anyway, it was SOOOooo nice to come to a gentle stop - like I usually do - without vibrations and the steering wheel shaking in my hands, so this was a distinct success that makes the car nicer to drive. As does less engine jerkiness from the gas and/or spark plugs. I'll be quite happy driving it daily, now. (until it starts getting below freezing and I want more traction, anyway).

45 minutes to change the rotors. Not quick enough to make Xist's list, but still quick....compared to two hours dicking around with spark plugs. Including starting up and cleaning up, everything torqued properly and checked twice(Cuz if you're not going back in again ever again, you should be damned sure its perfect).

Happy with her now, and for a job going finally smoothly.

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