LOL, good job. You really should have a working parking brake anyways so it's really no question if you should be fixing it or not.

Peter

 

I had an old 85 GMC Sierra that would roll backward like that, while in any grear including reverse.

 

Unbelievable.. Hey OP, your car is broken, stop driving it immediately, just because BlackZ06 says so!!

Amazing arrogance (and ignorance) from some folks here - BlackZ06 - are you sure you aren't "Evil-Twin" in disguise?

 

Nope .... but I "channel" Evil-Twin sometimes .... and you explain to me how a car "in gear" is doing what the OP claims ...... what part of the drivetrain is not connecting the rear wheels with the engine and then MAGICALLY reconnects when the engine is running .... which "magical" part is it ?????????

Or .... maybe, just maybe, I'm correct when I say he is not getting the car in gear .....

So looking forward to your explanation ......

 

Considering you took my jab in stride, I am obligated..

In a 4-cycle engine, there is no such thing as a "perfect seal". Some engines have better seals than others. There is always a small percentage of "leak down" (hence the term "leak down test", whereby a piston is brought to TDC on the compression stroke (int and ex valves fully closed), the cylinder is pressurized w/ compressed air, with 2 sets of gauges - one set measures the inlet pressure, one measures the outlet - the difference is the percentage lost, i.e. how good do your int, ex and rings seal. It's never perfect (or the piston couldn't move in the bore), but on some race bike motors I've built I've seen it as low as 2~3%.

So.. You should understand any motor under "load", i.e. trans in gear and gravity trying to pull it down a hill, *may* (depending on that all magical cylinder sealing described above) eventually turn-over. And once it gains a bit of momentum it may roll at a fairly good clip (a bit more than a crawl) until the pavement evens out and gravity's effect is less than the transmission multiplication ratios and cylinder sealing.

I always like to use extremes to make a point clear; say you put a car (any car) in gear, made sure the rear wheels had enough traction (no sliding aloud), had an 18-wheeler roll up to the rear bumper and start pushing.. Can't you imagine at some point the rear wheels would drive the trans which in turn would start to spin the motor over? Do you think the trans would break first? Does that make any sense to you? Have you ever heard of push-starting a car? Same concept, no difference. In the OP's case, instead of 5 guys pushing on his rear bumper, the weight, steepness of the grade and gravity are doing the work instead.

You can try this at home; get a breaker bar and a socket, throw it on the alt pully nut, and start applying force. You can turn the motor over by hand, with all the plugs in place. How do you think a starter works? Hopelly I've provided you (and others here) with enough examples to understand what is happening with the OP's car (and mine as well).

Simple. No "broken parts", no "guy doesn't know how to put his car in gear", just simple physics.

 

Having owned my share of British and Italian cars (Fiats ... not Ferrari's .... ) I am well aware of how push starting a car works.

I have also seen that a car can be rolled in gear by a steep hill, or by being pushed hard enough ..... I totally agree with you there also.

Now go back and read the OPs description of his problem. He is describing a car in NEUTRAL, not in gear ..... or that's the worst "explanation" I've ever read of a car rolling in gear with the entire drivetrain being rotated ......

Here's his EXACT words from the original post .......

The real problem is my car rolls backwards in any gear. I saw it is recommended to park in reverse. Still rolls. And when I say rolls I mean like I have the clutch pedal depressed.

I don't understand why the transmission is not holding. Is the engine compression bad? 85k miles. Is the clutch slipping?

I understand the importance of the parking brake and will always use it once I adjust it, but I've never seen a car roll like this before. Any ideas


Does that sound like a car rolling in gear .... NOoooooooo .... because HE IS NOT IN GEAR !!!!!!!!!!!!!

I think we can let this go now .... I think we're all in agreement at this point ....

Steve

 

Got to agree with you here Black.. either that or his engine compression is so pathetically bad that the motor WILL turn easily.. He rally should just jack up the rear and put it in 1st gear.. Try turning both wheels at the same time forward.. Pop the hood and watch the motor.. It it turns.. the car is IN gear and bad compression. It it does not.. Car aint in gear.. should tell the story right there..

 

Good explanation, but I don't think any of us were under the impression that leaving a manual car in gear magically locks the rear wheels.

Using your push start example, that's why you disengage the clutch while pushing the car to get some speed up, then "pop" the clutch to turn it over. It's kind of a biotch to push the car with first engaged.

Incidentally, I think your write-up is also the perfect explanation for why 8cyl of compression is more difficult to overcome than 4cyl, gearing and vehicle weight held constant.

 

Maybe the OP is using AMSOIL, and the engine is super slippery ! Everyone knows AMSOIL is the best oil on the planet, and makes the rotating assembly in an engine virtually frictionless..............

 

...but Royal Purple will make your car roll uphill while parked in gear.

 

Come on, just trying to have a little fun. Someone would believe it...

 

okay, so my '97 C5 6spd does the same thing. I have owned the car for 4 years 70,000 miles (car now has 135k miles) and the condition has not worsened over time. Depending on the slope it moves pretty fast but i'm not going to win any box car derbies anytime soon. It is not effected by putting it in 1st or 5th or even reverse.

"condition" = I park my car IN GEAR on any unlevel surface and it SLOWLY rolls downhill. My parking brake does not work so for 4 years i just don't park on hills or i use the rock method. As it rolls it does make a faint sound like gears in motion or the sound of drum brakes slipping (audible even when parking brake is off) (likely clutch slipping?).

factors - I know my clutch hydraulics are in poor shape. I can easily believe that there is some blockage in them preventing the clutch from 100% disengaging. it seems after it has been driven a little hard that it tends to move more easily while in gear. Shifting into first has always been a little resistant. I have flushed the tranny with synthetic fluid which helped tremendously. tranny fluid had little or no effect on the problem at hand.

Could it be a problem with incorrect fluid in the differential? I have never flushed the fluid in the diff. If not, my money is betting on the clutch and/or clutch hydraulics allowing the car to be ENGAGED IN GEAR and ROLL (but maybe not as freely as he described, that scares me). I would love to know exactly what the resolution is. Is it possible that the clutch pads have fluid on them reducing friction? I'm hoping to do the clutch/hydraulics install in the near future. If we haven't found out by then i'll report back the result. Thoughts?

**UPDATE so i parked on a steep hill last night to check it out and the first time i had to jump back in my car because it was rolling so fast i didn't think it was going to stop at the bottom of the hill. The second try on lesser grade i looked under the hood and sure enough the engine is turning over as the car rolls. Besides fixing my ebrake, what does this mean? My engine output has never appeared to suffer. No other problems, it just rolls downhill sometimes...

 

I think you missed his point. When an automatic is in PARK the differential still must hold to prevent rolling. Just as in a manual car if the engine isn't turning. The fact that an automatic has a parking pawl is irrelevant. (Unless the engine is turning) If an automatic car had a diff that was so bad it wouldn't hold, it would also roll away.

By the way....I'm on no ones side here... He was a bit harsh, but his facts on this particular issue are accurate.

 

These problems are not rocket science to figure out. It's the clutch or the compression.

Have a trusted associate get in the car and put it in gear. (INSURE that it is in gear) Open the hood and have him/her let off of the brake. If you can see the engine turning when the car moves, it is compression. If it actually IS in gear and the engine is NOT turning it is the clutch.

 

Agreed. I'll check it out and report back.

 

hey corvette people. a couple days ago I noticed the same thing with my rsx, I googled the problem and found this thread so I'm just curious to see what the results are.

in my case I could tell the engine was turning by the jerky way the car was rolling backwards, I could feel the compression strokes, so I'm gonna run a compression test when I get home since people seem to think that is one possible cause

 

Two things to keep in mind .....

1) ANY manual transmission car will roll when in gear if the slope is steep enough.

2) The parking brake is provided to assist in keeping the car from rolling.

In San Francisco it is illegal (and will get you a ticket with a hefty fine) if you park your car on a hill without "curbing" your wheels. If your car is facing uphill you turn your front wheels to full left lock (as if you were making a hard left turn) before leaving the car. If the car starts to roll the front wheels will contact the curb and the car should stop rolling. If you face downhill ... turn your wheels to the right.

Anytime you park on a slope "curbing" your wheels is good practice, if you can. Setting a working parking brake is also very important. Cars will roll against engine compression.

Finally, when it is time to replace that RSX .... take a look at a Corvette .... you will discover a whole new world of driving experience ..... real torque from the engine ..... excellent handling .... I (and every other Corvette owner) eat RSX at the race track (road course and drag strip) for breakfast ... we eat Porsche for lunch .... we have dinner on Ferraris .....

 

Thanks for the info . I should probably clarify a bit. I didn't park the car and have it roll away(whenever I am on a hill I always put it in gear AND use the e-brake), what happened was I was in the car doing something to my radio and I let out the e-brake so i could reach something easier with the car in 1st gear and it started to roll back in a jerky manor everytime the engine turned over.

I was asking about this on clubrsx and half the people say its normal if the hill is steep enough and others say their could be a problem with the clutch or compression, so I am just trying to find out whether something is wrong or not, but I guess the only way to do that is a compression test..the car has always consumed oil so maybe it is a compression issue...idk

also I parked my gf's 5 speed civic in the same spot and it didn't roll. I was thinking my lightweight flywheel might make it easier to start rolling

 

It is NOT your clutch ...... also your flywheel would have nothing to do with it.

Yes, possibly low compression would contribute to this .... so a compression check wouldn't hurt. I still wouldn't be too worried .... gearing has a lot to do with this issue also ..... I have no clue about how steep a slope it takes to get an "in gear" RSX to get rolling ..... but comparing it to your g/f's Honda isn't a fair comparison. Kinda like me comparing my g/f's Pontiac GXP Grand Prix to my Corvette .... both made by GM ... but TOTALLY different cars.

Finally ... made an edit to my previous post that you missed .... you should go back and read it .....

 

lol I am aware of the prowess of corvettes. also I should probably warn you not to under estimate RSX's...there are some turbo guys out there putting down 400-500whp on the stock motor and I believe there is a kit in the works for 1300whp or something(on built internals obviously). of course that is only useful on slicks and probably totally destroys the handling. but yeah of course the mighty vette is a far better performance platform then a wrong wheel drive I4 honduh(acura )..lol...u guys better look out for the GT-R though

and I agree about the clutch...a slipping clutch would make the car just roll back as if it were in neutral and make it impossible to turn the motor...and my clutch is new anyway