Car Rolls When Parked In Gear

[markmullen]

Can anyone help? My girlfriend's 2000 W reg VW Polo 1.4 has developed a strange issue.

When parked in gear (any forward, 1st to 5th) on a hill the car will sit so long before lurching forward slightly, then coming to a halt, then a few seconds later it will do it again. It almost feels like the car is trying to jump itself off, even with the ignition switched off. It has only recently started doing this.

The handbrake will hold it so its not a major issue, just a puzzling one.

Any suggestions?

[AndyLB]

Try putting it in reverse.

[EDLT]

Its not it gear properly?

[busta]

Sounds like low compression. Has it done a lot of miles? Does it seem more sluggish than usual?

[markmullen]

Reverse does the same.

Car has done 48k miles, not had a hard life, serviced on time.

[stuart-b]

I may be totally wrong but i thought this was more to do with engine compression rather than the actual gearbox stopping the car moving. except of course if you put it in reverse with it facing down hill.

I dont think the gearbox itself causes much rolling resistance but turning over an engine is bloody hard work.

So maybe it is that

[Defcon5]

These gearboxes are utter garbage - is it definately being put in gear properly?

[wackojacko]

1.4 will be trying to turn over if it's a steep hill as the actually flywheel and engine mass is very little compared to weight especially if you're still sitting in it.

[thewhooshparrot]

Its just the weight of the car facing down hill thats turning the engine over,assuming its a small engine you can turn them by hand so not an unusual thing tbh.

[munroman]

You say it's not had a hard life.

10/11 years old, 48K, so less than 5K pa.

Possibly used on short journeys?

Could be carbon on the valves, so they aren't seating properly or sticking piston rings.

Might be worth giving it a bit of a ragging, low gears, high revs for quite a few miles, (once it is warmed up properly), and see how it runs after that.

A hard life to a car is lots of short runs and low revs, with stop/starts thrown in, give it an Italian Tune Up!

[DubZeus]

Worst gearboxes ever, made of chocolate...the only thing I hated about mine.

[Matt UK]

stuart-b said:

I may be totally wrong but i thought this was more to do with engine compression rather than the actual gearbox stopping the car moving. except of course if you put it in reverse with it facing down hill.

I dont think the gearbox itself causes much rolling resistance but turning over an engine is bloody hard work.

So maybe it is that

Agreed.

[busta]

Matt UK said:

stuart-b said:

I may be totally wrong but i thought this was more to do with engine compression rather than the actual gearbox stopping the car moving. except of course if you put it in reverse with it facing down hill.

I dont think the gearbox itself causes much rolling resistance but turning over an engine is bloody hard work.

So maybe it is that

Agreed.

Yup, except for the 'reverse facing downhill' bit. There is no mechanism in an engine to stop it being turned backwards by the gearbox, so the results would be the same as with the forward gears.

[fluffnik]

munroman said:

Could be carbon on the valves, so they aren't seating properly or sticking piston rings.

Slow creep against (leaky) compression stroke, jump as it passes TDC, repeat for next cylinder...

[sonarbell]

^^^^^ +1

[stuart-b]

busta said:

Yup, except for the 'reverse facing downhill' bit. There is no mechanism in an engine to stop it being turned backwards by the gearbox, so the results would be the same as with the forward gears.

Good point.

[markmullen]

I shall give it an italian tuneup for her.

If that works I'll take it to work and get one of our mechanics to put a 993 turbo engine in it for her

[The fatboy]

if your handbrake is fine, it should be able to hold it even you are on neutral, it may be either your handbrake cable have to be adjusted or the rear brakes are nearly have to be replaced and even both.

[jagracer]

DubZeus said:

Worst gearboxes ever, made of chocolate...the only thing I hated about mine.

Defcon5 said:

These gearboxes are utter garbage - is it definately being put in gear properly?

The quality or amount of food products used in the manufacture of the gearbox is irrelevant to this, it's all down to the compression in the engine or how steep the hill is.

[Monkeylegend]

markmullen said:

I shall give it an italian tuneup for her.

If that works I'll take it to work and get one of our mechanics to put a 993 turbo engine in it for her

How come the girlfriend has to make due with a Polo when you have all those nice cars available ?