Piston Slap: Time to Twist Up the Tach?

TTAC commentator David Holzman writes:

Sajeev,

I have a new (to me) ’08 Civic LX 1.8 liter, stick, bought with 35k on the clock. The previous owner was a woman who traded it for a RAV4 I think (I bought the car from a Toyota dealer). I’m guessing partly based on gender stereotypes that she wasn’t availing herself of the high revs to flog a lot of performance out of the car.

If I want to wind it up a lot, does it need first to be broken in for high revs ? (Red line is 6750. I’ve taken it just a little beyond 5. It seems happy to do that.) If so, what’s the best procedure for this? For whatever it’s worth, after slightly under 2,000 miles since the dealer change the oil, it’s still clear, though ever so slightly darker than the first time I drove the car, about 1800 miles ago.

As an aside, for anyone interested, I got 36 mpg from Boston to Quakertown, PA, 34 from Quakertown PA to northern Virginia, against a strong headwind, and 39 driving home from NoVA, including a brief traffic jam on America’s Main STreet (the New Jersey tpk), and a drive through Manhattan, with a 70-plus mph average on the highway.

Best, –David

Sajeev answers:

First, I gotta compliment your machine’s inherent beauty, compared to the 2012 I sampled recently. Second, gender stereotypes? That’s just begging to be 100% wrong. Come on, son…welcome to the current millenia!

Let’s be clear on one point: the Civic (@35k) is already broken in, it’s too late for that. 6750 on the tach’s been your friend since you drove it off the lot!

Now let’s look at the logical extension of this question: what about a “warm up” procedure before twistin’ the Civic up to redline? Everyone has an opinion on the matter, and since TTAC readers seem to like my opinions, here goes:

1. Unless we are in below zero degree weather, there’s nothing wrong with immediately driving a vehicle after the initial cold start. Quickly move off the lot, but don’t move fast. Idle time is serious engine wear time: slowly circulating cold oil is a no-no, you want oil temperature up to spec ASAP. In a safe manner!

2. Do NOT rev it to red line until the temperature gauge is up to its normal place (whatever that is) for about a minute or so. Oil takes a little longer to get to temperature than engine coolant, and since many vehicles don’t show oil temp, just hang around for a while as the oil plays catch up to the coolant. Accelerate modestly, taking full advantage of the engine’s torque peak at this time. Google wasn’t helping me, but I expect the torque peak on a Civic LX is around 4000 rpm. So keep the motor in that general area while accelerating, or lower: traffic conditions determines this, obviously.

The insane high torque peak of some cars (Scion FR-S and even the 3.6L DI Cadillacs, to a lesser extent) give me serious pause on my advice, but whatever. No theory is perfect.

3. Once the motor’s lived at normal coolant operating temperature for “a while”, your only worry is the rev-limiter: try not to hit it. So now you can just go right ahead and beat the living shit out of that little motor.

Have fun!

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry.