Piston Slap: A Stupid Question About Engine Retardation?
I’ve got somewhat of a stupid question; why does my car roll when it’s parked in gear? My current (135i) and my previous whip (Mazdaspeed3) don’t like staying on any inclines without teetering ever so slowly backwards in a scary, slow, lurching motion.
Another silly question is have you ever heard of a car making a slight leaf crunching noise when engaging into gear? And not just any gear but a specific gear. (2nd) I’ve got this issue currently and it drives me nuts because I’m getting all sorts of dealer nonsense saying it’s a pressure plate issue or they don’t hear anything while forums have told me that it may be the release bearing is loose, or the the release fork isn’t properly greased . Bear in mind that this is all Greek to me. It’s not a very loud sound, something that I’m cursed with for living in a relatively quiet neighborhood when I’m shifting, dreading the 2nd to 3rd gear shift as right when 3rd is engaged and the clutch is released… “crunch”. Or 2nd to neutral. “Crunch”. No other gear! No clutch vibrations or anything. It’s barely audible in the cabin but when the windows are rolled down, I can definitely hear it. One little itsby bitsy “crunch”. I had actually overlooked this issue for quite some time as there were a bunch of leaves during autumn but once the leaves cleared, I realized that my own car was CRUNCHING.
Hopefully it’ll be something you can use, thanks for the reads, your columns are awesome!
Thanks for your letter and the Kudos. No, it’s not a stupid question!
Like you suggested, hill holding prowess depends on the engine braking skills of your motor. The bigger/heavier the car, the more engine braking you’ll need to stop the inertia. And, like you noted, engine braking comes from the compression ratio of said engine’s design. While both the 135i and the Speed3 have high compression ratios (10.2:1 and 9.5:1) for turbocharged motors, perhaps that isn’t enough for the vehicle’s weight, gearing and slope of the incline. And depending on the motor, your Acura had ratios that may or may not prove my point.
Then again, the Integra is much lighter than your last two vehicles…and was geared to compensate for a lack of turbo-torque in the powerband. Especially in first gear. With more gear and less weight, I bet that’s why the Integra fared better. But I’m sure the B&B will pull up gear ratios and prove me wrong. I’m cool with that.
Now about the silly crunching question: that’s tough. The items you discussed could be the problem, but I think the synchros are at fault. That’s because it happens as you release the clutch in a certain gear. Judging by your cars, you might be a hot rodder. A racer. A gear jammer. If so, it might be time to find that next car of your dreams. I’m just gonna go waaaay out on a limb and guess that you don’t keep these hi-performance machines for longer than 5 years. I just love how transmission problems bring out a craziness in a diagnostic blog posting!
Latest Car ReviewsRead more
Latest Product ReviewsRead more
- Golden2husky Cash for clunkers was a horrible waste of resources. "Car dealers are asset rich and cash poor. Cash flow is something we look at every single day in a car dealership," she continued. "What if that $200,000 the government owes me is the same time I have a big payroll, and I have floorplan to pay off and, oh, it's tax time? All of a sudden, the dealer is in a cash crunch."Oh, my heart is just breaking for them...and with all that ADM, they can go screw themselves...they should have a line of credit. Use it.
- Sgeffe How much of a current draw is one of those digital plates?
- Ajla I had a chance to drive a few Toyota/Lexus products the last two weeks. The turbo-4 is basically charmless. I don't see much reason to go for it over the over the 2.5L or a HSD hybrid. Maybe if you live at higher elevation?The "HybridMax" is interesting. The stronger rear motor gives it more of a RWD feel. It isn't a sporty powertrain but was reasonably smooth and powerful.
- MaintenanceCosts A fair deal would be a single tier with at least a 33% raise for everyone over the life of the contract to make up for recent inflation and quite a few below-inflation years.Retiree health benefits and pensions are ridiculous, could legitimately bankrupt the automakers (unlike the raise), and shouldn't be in the deal.I'd really like to see the union accept a bit less cash and go after the 32-hour workweek harder. I think all of our society would be better on a four-day-a-week schedule, with little if any loss of output - business after business has found that people are more productive with four-day schedules, and almost everyone who tries it keeps it.
- Jordan Mulach Hey Matt, this story has already been uncovered as not being the Camry update. Toyota US actually took independent digital renders and used them.You can see more about it from the artist here: https://www.instagram.com/p/CxmR8idB9C3/?img_index=1