My Mustang reverses itself out of the driveway overnight.

Details: 05, GT, Manual, 160k, new OE clutch kit, Clutch master, slave.
I park in 1st gear with the ebrake pulled semi-tight (I'd like to get some longevity out of it).

My problem here is that if my ebrake didn't even work, my car should sit tight in 1st gear and not reverse itself out of my driveway, even at an incredibly moderate pace. I'm told I have low compression. I have yet to do a compression test. The car burns a bit of oil as well. The car drives and sounds fantastic. I let it warm up before I drive it every single time I take it out. I fill it up with mid-grade. I have only driven it wide open twice and I was told by the previous owner that taking these engines to their limit is really bad for them.

If someone could give me an answer as to why my car moves against the selected gear, that would be great. I don't know if this is a common problem or not. If I need to find a replacement 4.6 on Craigslist or something, what kind of money am I looking at? At the very least I'd like to perform an OE comparable rebuild and just drive my car as is in the meantime.

To make things clear: I'm not asking for a solution to keep my car from backing out. I can buy a chock for 5 bucks and I can pull my ebrake all the way up. I'd like to know why my car can't hold itself in gear without an ebrake or chock.

Thanks all!

How steep is your driveway?

And this isn't considered 'tech' on this forum. Your thread will probably be moved to the appropriate sub forum.

Spinks said:

I park in 1st gear with the ebrake pulled semi-tight (I'd like to get some longevity out of it).

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that's a new one on me - 11 years I've been involved w/ S197 chassis

Spinks said:

My problem here is that if my ebrake didn't even work, my car should sit tight in 1st gear and not reverse itself out of my driveway, even at an incredibly moderate pace. I'm told I have low compression. I have yet to do a compression test. The car burns a bit of oil as well. The car drives and sounds fantastic. I let it warm up before I drive it every single time I take it out. I fill it up with mid-grade.

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KISS - car slipped out of gear or was never in gear.

Spinks said:

I have only driven it wide open twice and I was told by the previous owner that taking these engines to their limit is really bad for them

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WTF.... drive it like you stole it, guys have pushed 400+ whp on these cars to 6500 rpm over and over.

Spinks said:

If someone could give me an answer as to why my car moves against the selected gear, that would be great. I don't know if this is a common problem or not. If I need to find a replacement 4.6 on Craigslist or something, what kind of money am I looking at? At the very least I'd like to perform an OE comparable rebuild and just drive my car as is in the meantime.

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never heard of such a thing and the motor is not the cause.

skwerl said:

How steep is your driveway?

And this isn't considered 'tech' on this forum. Your thread will probably be moved to the appropriate sub forum.

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boardline - I'm going to leave it here for now.

skwerl said:

How steep is your driveway?

And this isn't considered 'tech' on this forum. Your thread will probably be moved to the appropriate sub forum.

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My driveway isn't very steep. My car is super lower though so I do have to enter at an angle. The previous owner had the reversing out issue when his ebrake cable snapped and his driveway wasn't steep AT ALL. It was an incredibly slight incline.

Also, that's okay. I looked through the other forums and most of it seemed like general discussion. I feel like the specific part or malfunction would be considered technical, but I'm all for organization, especially if it helps people like me get help!

stkjock said:

that's a new one on me - 11 years I've been involved w/ S197 chassis

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It's got a new ebrake cable and pulling them tight loosens them. Not instantly, but over years time. I'd like to not have to fuck with it for a long time if possible.

stkjock said:

KISS - car slipped out of gear or was never in gear.

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No. It was in gear when it had made itself to the end of the driveway. I double checked because I was so surprised by it. That's why the clutch was replaced. I thought it wasn't fully engaging sense it was in gear.

stkjock said:

WTF.... drive it like you stole it, guys have pushed 400+ whp on these cars to 6500 rpm over and over.

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I'm told the mod 4.6s have blowby or burn oil so if you're really pushing it and you haven't checked the oil level recently you could be doing some permanent damage.

stkjock said:

never heard of such a thing and the motor is not the cause.

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I've talked to a lot of professionals and they all are telling me it's a compression issue. I do know that the previous owner had tightened a spark plug that backed itself out. Maybe the compression/combustion is pushing it out again? Maybe the threads in the head are fucked.

Spinks said:

It's got a new ebrake cable and pulling them tight loosens them. Not instantly, but over years time. I'd like to not have to fuck with it for a long time if possible.

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first time in 11 years I ever heard of such a thing. the ebrake freezing yes, but never wearing out.

stkjock said:

first time in 11 years I ever heard of such a thing. the ebrake freezing yes, but never wearing out.

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It goes for any e-brake that uses a metal braided cable. If you pull it as tight as you can, over time it will stretch. After it has stretched, its tightest setting will be less effective. It's not a Mustang thing. Just a non-hydraulic e-brake thing.

o.0 do I smell a troll..

06monera96 said:

o.0 do I smell a troll..

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No I promise I'm not. I've been asked that a lot. I was hoping joining a chassis specific page would give me a quick answer. Clearly this is unique even to the chassis.

The car does not have such low compression that it allowed the car to roll out of the drive way in gear, end of story.

RocketcarX said:

The car does not have such low compression that it allowed the car to roll out of the drive way in gear, end of story.

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Give me your reasoning.

Look, I agree with you. I feel like I could take the engine out of the car and 1st gear would hold it in place. I'm told by mechanics everywhere that I'm wrong and that the air pressure in the cylinders is what holds the vehicle in place. This makes no fucking sense to me, but people who handle shit like this for a living are telling me otherwise. What is your reasoning. What could you use as proof that this is incorrect?

I think even if you had no spark plugs, the friction of the engine, transmission, rear end, and tires would hold the car on a slight incline. If your clutch isn't engaging, I could see it rolling like that but you'd have a noticable issue with driveability.

Bingo said:

I think even if you had no spark plugs, the friction of the engine

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None if there is oil in it.

Bingo said:

, transmission

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Completely depends on the gear.

Bingo said:

, rear end

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Moves freely

Bingo said:

, and tires

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Move freely and are stopped only by obvious obstructions.

Bingo said:

would hold the car on a slight incline. If your clutch isn't engaging, I could see it rolling like that but you'd have a noticable issue with driveability.

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You're wrong about pretty much everything here. I do appreciate your input. If you're trying to help, I appreciate that, but if you don't have any idea what is causing this problem, I'd like if you let the experts chime in. Mind you, I don't know why I have this issue either. I'm relying on people who know the answer. I don't. You don't. Let's see who comes out of the woodworks.

So do this, put he car in gear, no E brake and push it...let us know how that goes.

Too much missing info. I'll wait for the Paul Harvey version.

if the car is pointed tail first down a hill, dont you use reverse not first?

honestly not sure, i rarely ever have to park on a steep hill, let alone worry about the car rolling on one

RocketcarX said:

So do this, put he car in gear, no E brake and push it...let us know how that goes.

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I'll do that. Not a joke.

skwerl said:

Too much missing info. I'll wait for the Paul Harvey version.

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I'm a mod on two model specific Vbulletin boards. 10,000+ members combined. I get that there are inside jokes here. I understand that you are asked a lot of stupid questions. What information would you like? I am looking for help with my car.

Careful about who you are claiming are not experts. Look at the post numbers on these guys, they ARE experts when it comes to Mustangs and I am with them. I've never heard of compression being the issue and if you can find the info that shows definitively that its compression that holds a car in gear post it otherwise don't tell them they're wrong. Because your responses to Bingo, are wrong.

1. Oil does not eliminate friction
2. 1st gear is very hard to turn
3. Rear end doesn't move freely - hint it's connected to the trans which when in gear and clutch is depressed is mated with the flywheel which is why Bingo mentioned it
4. Wheels really don't move freely - gears connect to driveline which is connected to trans which... see item 3

Good luck. Hope you figure it out on your own because you just pissed off everyone who was willing to help you by telling them they are wrong when they gave you very good advice.

I had a feeling this guy is trolling...

these cars use a composite cable not a metal braided one.

does the motor turn over when its rolling down the driveway? if so, yes you have almost zero compression in that thing.

if not, your clutch cant hold the weight of the car. check your install.

if it runs good pull the ebrake up further, problem solved.