Accelerator blown?

redtom

Was idling at a junction on fri night after a 3 hr drive, car was out of gear, my feet weren't near any of the pedals when I noticed the car sounded like it was revving up and down and then I saw the rev needle was going up and down too - when I had to move off, I put it in first and lightly pressed the accelerator but the car revved away like mad and the needle shot up before I moved - the accelerator pedal feels quite loose too but I can't remember if it was like that before

situation didn't improve much over weekend, but sometimes the car sounded normal enough and there was none of this revving up and down - had it in an Advance Pitstop but couldn't get much of a clear answer as to what was wrong and they couldn't take a proper look at it til monday - couldn't leave it there as I had to head back home today, made it back in one piece tho

another thing I noticed is that when I was moving along and accelerating, the car didn't respond straight away and then the acceleration kicked in quite suddenly, same thing when taking foot off accelerator, car didn't respond immediately but then suddenly slowed down with a jerk...

Taking it to a garage tomorrow but was just wondering if anyone recognises what it might be?

Mr.Diagnostic

redtom wrote:

had it in an Advance Pitstop but couldn't get much of a clear answer as to what was wrong and they couldn't take a proper look at it til monday

Hi,

The right thing to do is to bring it to a garage as you have said you plan to. There is no way that anyone could tell you online what the fault it. the type of fault you describe could be caused by many different things, most of them simple.

What struck me about your post was the mention of Advance. Advance are geared up to fit general service parts and do not get involved in diagnosing running faults. The best thing you could do with any advice you get from advance is ignore it.

Sorry I cant be more help.

redtom

Cheers - new to this motoring lark, so learning all the way (first issue with my first car)

antodeco

Did u drive behind any truck that was shooting out aload of muck or dirt? Sounds like ur air filter may be a little blocked. As previously said though, it could be one of a few things

redtom

Not that I can remember - just hope I can describe the problem clearly enough for whoever's looking at it to give them something solid to go on

crosstownk

What sort of car is it - year? make? model? This info is critical.

Best solution is obviously a garage if you don't know to much about cars and/or would prefer not to. You're wasting your time with Advance for diagnostics - as Mr.Diagnostic said, they are really only equipped for the really obvious and routine stuff, although some branches are better equipped than others.

mantaraver

I would bet money that your acellerator cable needs to be lubricated or replaced. Do I get a prize ?:)

Puff Puff Pass

try giving it throttle by pulling the cable under the bonnet does it react the same?

crosstownk

A lot of assumptions here - until we know the make and model we won't even know whether the car has a throttle cable or has an electronic throttle.........

mik_da_man

I had a similar problem on An Astra I owned and it was the Crankshaft sensor.
But as said above it could be a number of different things

redtom

Thanks for suggestions so far - it's a 96 Polo, 1 litre - off to garage over lunch and book her in - hope it's something simple

crosstownk

A 96 Polo has a throttle cable - but I doubt it's at fault. The first place to start is at the throttle body - get it cleaned and reset. It could also be a dodgey lambda probe or possibly a bad plug lead. Either way it will need a diagnosis machine to be 100% sure.

Vinnie K

crosstownk wrote:

A 96 Polo has a throttle cable - but I doubt it's at fault. The first place to start is at the throttle body - get it cleaned and reset. It could also be a dodgey lambda probe or possibly a bad plug lead. Either way it will need a diagnosis machine to be 100% sure.

Have to agree with you there, there all common faults with the polo, make sure your mechanic has a diagnostic machine to pin point the prob straight away or else he could be running up extra cost eliminating(spelling) problems one by one!

cantdecide

i had a beemer that used to hunt (rev up and down) it was the lambda sensor. might be the air mass meter. im getting one for my audi tomorrow. €100 exchange from main dealer.

Darragh29

redtom wrote:

had it in an Advance Pitstop but couldn't get much of a clear answer as to what was wrong

Mistake number one. Just ignore anything these guys have told you.

redtom

Booked into garage tomorrow morning - how do I ask him if he's got a diagnostic machine without sounding like I haven't got a clue what a diagnostic machine actually is (which I don't)?

BeardyGit

Lads,

Some of the advance garages are actually running diagnostics now. I know the Carlow depot have a qualified mechanic now and a full diags system running off a HP tablet PC, with all sorts of dongles and sensors etc. They're doing timing belts etc.

Don't knock advance as a whole - Each depot differs from the next.

Gil