I noticed My 520i when parked on a hill, can move even if the 1st gear is on

(obviously can move if there is no handbrake).

I always tought that with the gear on, a car won't move and the handbrake is a security surplus. But I noticed that the car moves by little steps until I pull the handbrake. Never noticed on other cars, or almost not noticed so evidently.

Any advice? Is that abnormal?

 

Yes. The only thing keeping the car from moving is whether the wheels can move pistons against compression load. The smaller the engine, and also wear of engine factors in this, the easier for the car to roll in gear.
If on a hill almost any car will move some. An E60 wears 1600 Kg and up. Lots of weight to work to motor engine over.

 

maybe it can be a compression issue?

the engine is a M54, 6cyl.... not so small

 

Put the car in to reverse.

 

its normal with every manual car. when you park the car and leave it in gear, the engine being off is what holds the car in place. and with an engine off, it will turn, with enough force.
thats why you're supposed to use the parking brake.

 

iI knew higher the gear, lower the resistance an engine can oppose to the movement...why you suggest that option?

 

is the "enough" amount infact that I can't figure out.
As said in the topic, E60 is a heavy "beast", and I assume the force needed to put it in place may be a lot. But I'd never figure out that on a not-so-steep hill the auto would move.
but on another forum has same responses, so it's reassuring.

can you suggest me eventually seals/gasket to check (excluding head gasket ) to avoid compression loss?

 

You're right. I was wrong. Lowest gear. Reverse would be best. I'll go fix my original post.

 

You have two choices:
1. Stop car, remove a spark plug or injector on a diesel, stuff a rag into cylinder, and then put in gear and lock car.
2. Set the park brake and leave it in gear. Leaving it in gear is the back up to park brake if the brake is weak, not the other way around.

You can spend a lot of money on the engine getting the cylinders bored and oversized piston fitted with perfect dimensioning to assure the best ring sealing and you would have no assurance that it will not creep when parked on a hill with no park brake set.

Actually another choice: wheel chock blocks.

 

stop worrying about nothing. a car with a manual trans is not designed to hold a car on a hill. thats why cars have parking brakes. and no engine in the world will hold compression forever. it will always bleed off some.