Anonymous writes:
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. Gears don’t matter as it simply increases the speed that the car wants to roll at. Strangely enough, the oldest car that I had driven was a 98 Integra that could sit on inclines all day without this ever happening. Common wisdom says you’re supposed to park with your PARKING BRAKE engaged and I do but I still get a bit scared and would like that secondary backup of my transmission being able to hold them in place. I’ve researched a bit on the manner, seen NOTHING related to this so I’ve more or less boiled it down to vehicle weight (both the recent cars are pigs compared to the Integra) and engine compression and gear ratio (both significantly higher in the more modern cars). Some insight on the manner?
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!
Sajeev answers:
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!
If your on a hill, after you push in the clutch, the tranny freewheels. The clutch disk isn’t touching the flywheel, so the car can move. When you let the clutch out, the clutch disk engages with the flywheel and you move forward. You can let off the brake, let the clutch out, and give it enough gas to move without stalling or rolling.
Roll back is really scary when it’s the car in front of me and I am afraid they’ll hit my grill. Part of the reason manuals are being KILLED in my city. The other part: people’d rather have that hand on a cellphone.
I’m glad manufactures are putting the hill-holder features back in manual-equipped cars. Makes a huge difference.
I have a hill-hold function in my car now. I have used it exactly once, to try it out. In the meantime, I have driven manual cars for 35 years and never rolled back into the car behind me yet.
th009,
whaddaya mean, you’re not incompetent? Get with the program, you darned relic!
I do think makers have gotten a lot better at idling the cars infinitesimally above the rpm and throttle position required to avoid a stall than they were in the old days. Combine that with some drive-by-wire throttle systems not being exactly the most instantaneous, and your balance trick is probably slightly tougher to pull off these days than in the days of carburators.
At the rate my memory (and probably the rest of my brain) is deteriorating, I’ll be incompetent soon enough!
I think you’re right in your conclusion. Though I have far more torque at my disposal than in the old days, so it’s still not so bad.
The trick to driving a manual on hills is to be quick quick with your feet. That is, best to move your right foot quickly to the accelerator, press in a little, while partially letting out the clutch, which you should begin to let out right as you release the brake so it can partially hold the car. Do it quick enough, the car will barely roll back, if at all.
Sadly, most people are not as quick with that as they should, so the car rolls back before the clutch engages.
That said, even many cars with automatics will have a hill holder, especially the automated manuals, like in the Ford Fiesta for instance since it’s essentially in neutral to disengage the clutch when at a stoplight.
I’m glad a hill holder is being reintroduced in so many cars as I can see it becoming a boon. Especially when having to get out of a parking spot on the street in the uphill direction, having to manipulate the clutch and a foot actuated parking brake in my old 92 Ford Ranger, that gets tricky so I avoided parking uphill whenever possible in it. The Hondas before it, no problem since they had a hand brake to manipulate.
Every now and then my supercharger causes my 300cSRT8 to stall when I do sudden reverse manuevers without giving enough gas. Problem is, only people with manuals expect a car to possibly stall and since my state is dominated by automatics, even if I try to pretend I have a manual and I’m out of gear – people don’t recognize it.
How exactly are Americans taught to drive? How can you have a discussion of hill-starts without mentioning the biting point of the clutch?
Here is the drill from where I come from, indeed a hill start is a compulsory part of driving tests.
With the parking brake engaged, press the clutch down fully, select first gear and then set the gas pedal to a depth of a pound coin (a figurative term as the depth differs between cars) so that the engine note changes to a lively but steady hum. The clutch pedal is then raised to about half-way until the biting point is reached (not too high that the car strains and groans, not too low that the clutch plates aren’t engaged). Now the car is prepared.
After making the necessary observations of the road ahead and behind and a signal if necessary, the parking brake is released and a little more gas applied and as the car starts to move forwards the clutch is smoothly raised to its fully up position and the left foot is taken off the clutch pedal completely.
This method when carried out correctly ensures that there should be no chance of rolling backwards and that the car will only move off when it is safe to do so immediately after the necessary visual checks of the road ahead and behind have been made.
All you folks above discussing how to hill start do realize the question is about PARKING, don’t you?
My ’88 Audi 4000S quattro non- turbo liked to run away down my steep driveway all by itself. Nothing quite like coming out of the house of a morning and NO car. Wait a sec, there it is, wedged between two trees, 100 feet downhill.
Didn’t use the parking brake due to icing up in winter, but changed my mind after that. You can guess what happened the next winter. Car would not move after a sudden deep freeze. AWD and stuck rear brakes. Interesting.
Went back to leaving in gear only. Wrong. Ran away again. Only car I owned that ever did it. So I tried an experiment. Sat in the car, engine off, in low gear and rocked back and forth in the drivers seat. After a minute or two, slowly at first, she motored off down the hill. Would have been better if I’d had the key in the ignition. No steering, no brakes with engine off, unless you push really really hard. The two trees completed my stop once again. Much fun.
I sympathize with Sajeev’s OP.
Interesting (and hilarious) story, another_pleb! Did you ever find out why it did that?
Just use the hand brake, rather than the transmission to hold the car in place. They’re generally cheaper to fix/replace than transmissions anyway.
Exactly. Even dealer mechanics seem to think that putting a car in gear when you have a manual is the same as putting a car in “Park” when you have an automatic.
It isn’t. There is a proper alternative: it’s called “Parking Brake” for manual-transmission cars. Probably a reason for that.
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SAABs required that you had to put the car in reverse before removing the key.
I put my Outback in 1st or R depending on which way the car is facing…plus the emergency brake. There isn’t alot of flat ground in Idaho.
It’s good practice to put it in gear as a backup, especially if the grade is steep, but at least let the parking brake hold the car, not the gearbox’s internal gears. Even in automatic cars I always used the parking brake for this purpose, with the same reason (cheaper to fix/replace). Plus, you had to use the parking gear sometime to keep the rear brakes adjusted (for those with drum rears).
Putting the transmission in gear while you park will not wear out the transmission. What are you worried about?
Parking in reverse offers the best hill holding. Because R is always the lowest gear ratio in the transmission, it takes best advantage of the internal friction and compression of the engine to keep the car from moving. Personally, I switch between 1st and R depending on whether my car is likely to roll forwards or backwards, this ensures that the engine will always rotate in the proper direction if the car were to roll away, or is hit from the rear.
Parking brakes almost always work best when the car wants to roll forwards, so leaving your car in gear with the brake on is likely unnecessary, however a parking brake is very limited in its ability to hold the car when it wants to roll in reverse. In this case, the use of R and the parking brake is the best option.
anonymic: bingo!
1st or reverse. Usually if I am climbing up my driveway (flat at the top), I leave it in 1st. If I was backing up the driveway I leave it in reverse. Then I always apply the parking brake. Otherwise my car is totally dependent on the engine compression/braking to hold it in place which is unreliable. I had a ’66 Mustang years ago that would slowly chug down the driveway in gear even with the lousy parking brake applied. There was SO much wrong with that car.
With an automatic I still apply the parking brake when parking. Then I move the gear selector into park. Keeps the parking mechanism from binding but if the parking brake should slip, the car of course can’t go anywhere because park will hold it.
Amazing how many people will park on the steep part of our driveway and not apply the parking brake at all. When they depart it requires either a big pull on the shift lever followed by a giant bang as the parking pin/claw releases. Now wonder their cars are clapped out so early. They don’t know how to take care of it.
The one that makes me cringe is when people slam it into park while the car is rolling a little or switch from reverse to drive what the vehicle is moving. It’s sloppy and probably a good reason they’ll need a rebuild before 125K miles.
When shopping for a car I honestly look for a manual transmission AND a parking brake lever in the center of the car. Yeah – a dying breed. The pedal parking brake is useless to me b/c sometimes I use the parking brake to hold the car on a steep hill in traffic to prevent rollback.
Pull up to the light on a steep hill, hold the car with the brake pedal, right before the light changes I’ll apply the parking brake while holding the release button to avoid wearing out the ratchet mechanism or making the noise or impeding the quick release of the parking brake.
Anyhow, move my feet to the accelerator and the clutch and before the light changes to green, let the clutch bite slightly and no throttle increase but the RPMs might sag 50 rpm and the fuel injection will compensate for that automatically. Light turns green – release the parking brake, allow the clutch to bite more and give it more gas all at once.
The car will take off with zero or almost no rollback and my passengers are unaware of what I just did. It reads as complicated but it’s easy.
I have not had to repair my parking brake in 237K miles of driving like this in the one car and 176K in the other car.
I still despise an automatic transmission. Rode in a VW DSG equipped vehicle over the weekend and it is a fair compromise but I still prefer to row my own gears and the DSG doesn’t seem like something that would last 300K miles without a rebuild.
I also feel like I remember hearing something about modern cars, having more efficient engines, were inherently inferior at engine braking. For what it’s worth, my 97 Cavalier was better at it than my 10 Civic, and they were about the same weight.
Assuming compression and gear ratios aren’t significantly different between the newer and older vehicles, manufacturers efforts to reduce rolling resistance and driveline losses probably play a large role in this.
That’s a very good point. Although I strongly doubt that a RWD car will ever have as little driveline loss than a FWD car, even a 98 model.
If I remember properly -and please correct me if I’m wrong-, in San Francisco you also have to turn the wheels toward the curb…the police will fine you if they find that you didn’t take that extra precaution while parking in its hilly streets.
Yep, they do that in Tacoma, but Seattle does not have a rule for that, as far as I know, but I STILL turn my wheels out when uphill so the rear of the front wheel can rest against the curb, turn in when parked downhill.
I use reverse for all parking since its even a lower gear than 1st when I had a manual, and used the parking brake when parked, be it level ground, or a hill, and Seattle has hills, some fairly steep too.
This is true for all of California, just especially so in San Francisco. It isn’t necessarily wheels toward the curb – ciddyguy has it right.
That’s a good idea anywhere you’re parked on a slope. Parking brakes do fail sometimes, and transmissions sometimes slip out of “park”.
Parking on hills is covered on page 195 of the 2011 edition of ‘Driving: The Essential Skills’.
If you park in gear without the parking brake, the weight of the car can move the wheels which in turn pulls the pistons in the engine up and down which causes the lurching motion you describe.
If you park facing uphill, you should have the parking brake engaged and front wheels turned away from the kerb, if the is one and away from the road if there isn’t a kerb. You should also shift the car into first gear.
When parking facing downhill, you should leave the parking brake engaged and have the front wheels turned away from the road and leave the car in reverse.
With an automatic transmission, you should always leave the gears in ‘Park’ when parking and follow the other instructions about the parking brake and wheel position.
As for the gearbox problem; you’re on your own with that one, mate!
Regarding your rules for turning tires away from the curb when parking uphill — those rules don’t work well in the city.
Turning your wheels away from the curb introduces the possibility of your car rolling out into the street if the car is bumped or pushed back and it starts rolling downhill. I nearly got charged with an expensive accident when my car rolled out into the street and hit three parked cars. The only thing that saved me was a security camera caught someone else releasing the parking brake and pushing my car back to cheat themselves some extra parking space.
So, forget the esoteric rules for parking uphill. As a practical consideration, I strongly recommend parking close to the curb and ALWAYS turning the front of your tires into the curb. This greatly reduces the chance of your car rolling out into the street and doing damage — whether it’s due to mechanical- or human-induced issues.
If the kerb is high enough, it will stop the nearside front wheel should the car roll backwards and that will prevent the car from rolling into the road. Parking uphill with the wheels facing the kerb will cause the car to roll further before its nearside rear wheel makes contact with the kerb.
Parking on a slope is more difficult than on the flat and can take more room. You should leave a larger gap between your car and other vehicles to allow more room for manoeuvering. A larger gap will help both you and others
The important thing to remember is how the car is secured with both the correct gears and a firmly applied parking brake. If this approach with brakes and gears were ‘belt and braces’ then turning the wheels is like sewing your trousers to your shirt – a last line of defence.
Wrong, Tacoma, a city requires you turn your wheels as described, or you get fined. This is so the car can roll into the curb either way and NOT into the street if your parking brake should ever fail.
The only way your car reaches the street with the wheels pointed away from the curb is if you didn’t park close enough to the curb.
I always leave my STi in 1st pointing uphill or reverse pointing downhill, as well as using the Parking brake. Why not use both if you have both?
+1 There is a reason it is called a “parking brake” not an “emergency brake” – and adjusting the parking brake or even replacing it is a heck of a lot cheaper than syncros (ask me how I know).
How would parking in gear on an incline wear the syncros?
I use reverse both up and downhill. There are no sycnhros and the ratio is usually greater than first. Having said that, once the gear is fully engaged, synchros are not doing the work. Engine compression works in both directions of rotation. I use both, just like I use the parking brake and park on an automatic.
Compression is not so much a factor for holding a vehicle while parked. All engines have small compression leaks due to the gaps in the piston rings. What counts is the friction of the engine (plus vehicle weight and gearing of course). Big engine, flat tappets, thick oil = lots of friction. Small engine, roller tappets, thin oil = less friction.
Since the OP says a 2nd-to-neutral shift also “crunches” I would not suspect the syncros; they are only active while shifting from neutral into a gear.
If the clutch mechanism was “crunching”, it should be independent of what gear is being selected. The clutch cannot tell what gear you are in!
Bottom line: set the parking brake and handbrake if you are on a hill.
I think that sign is in Canton PA, a nice small town that doesn’t like trucks using the Jake Brake
1st gear or reverse will give you your highest hill holding power. successively higher hills will hold less and less. The higher gears increase the road’s mechanical advantage on the engine. That’s one reason to bump start in 2nd gear instead of 1st – it’s easier for the wheels to turn the engine than it is in 1st.
Reverse will give you the most hill holding power. Reverse gear is almost numerically geared higher than 1st. The typical implementation of the reverse gear- is an additional sliding gear that slides over the first gear on the cluster. Hence it is an additional reduction of the first gear.
Did he seriously call his last car a “whip”?
Interesting problem, the only vehicle that has had a problem that I’ve seen was a diesel that was left in gear on a steep slope with about 8k of trailer behind it. I wonder if the slop in the drive train is what is the problem.
I’m glad someone mentioned above that the piston rings (seals) are not capable of holding pressure, but leak at a slow, steady rate. When you use only gear engagement on a hill to hold the car, the wheels are forcing air into and out of the cylinders. The engine will rotate slowly as the cylinders admit air in or out. Your car will move.
This reminds me of an incident my wife had with our MT Saturn L-Series. She forgot to do either one when she parked the car in our condo garage. It slowly rolled out into the middle where people drive by. She claimed surprise when she learned there is a bit of a slope. I found it later with a piece of wood behind the wheel and an orange cone behind the bumper.
I suspect that the crunching noise is coming from the clutch release mechanism. Do we know if this is a cable or hydraulic release clutch?