Engine trouble.. Pls help!!

MunkyHed

Alright biys!
I'm having trouble with my car lately... anyone have any idea whats wrong with it. I havent a clue!
Its a 00 Audi A3 5 dr 1.6L
Basically the problem is very intermittant and is composed of two main problems.
1. When i turn the key to start her up sometimes the engine won't engage, it makes the usual whining sound but the engine just doesn't kick in. After a few goes it always starts but i understand that this can be bad for the starter motor.
2. While driving, sometimes the throttle takes on a life of its own. I could be driving along and going from 2nd to 3rd or 3rd to 4th gears and the throttle just gets stuck at about 3000 revs! I have to pull in to the hard shoulder straight away. When the car is stopped and in neutral and my feet are completely off the accelerator the engine is still roaring away at 3000 - 400 revs. and sometimes it keeps rising slowly.
Scary stuff eh! I've put her into a local garage and he found no fault but i'm bringing her back at the weekend. I'm just afraid he won't be able to duplicate the fault and therefore not be able to fix it.

Sorry for the long-winded post!
Any advice??
Munky

le-dub

I don't mean to cruel, but even if someone told you what the problem is and how to fix it, i don't think from what you have said you will have a clue what to do. The best thing to do is leave it into a garage and get it looked at before you so some real damage to your car and could cost a lot to fix

SouperComputer

it could be a gummed-up throttle body. Fairly common though.

You need to grab a can of carb cleaner and clean the throttle valve. A few peeps on boards have posted about it before so you might find some other posts.

MercMad

Yes or it could be a sticky throttle cable !

A lot of new cars WILL NOT start if the throttle is depressed whilst turning the key !

So if your cable is sticky (I assume you have checked your floormat is not fouling the pedal ) then the ECU sees the throttle IS open and the car doesn't start so well !

This also explains your intermittant problem with the revs rising erratically !

alias no.9

On a VAG 1.4 or 1.6 engine, the imediate suspect has to be a gummed up throttle body. Did the garage just hook it up to a diagnostic or did they do some investigative work?

Lex Luthor

If you don't get an answer here, your best bet is to post on an audi specific forum....I use them a lot for my car and find them a mush better source of information

http://www.audiforums.com/
http://www.audi-forums.com/

There is a mechanic in Sallins who specialises in German cars and I'd recommend him if you live nearby. He has all the equipment to diagnose your problem and he won't fob you off like the dealers do.

MunkyHed

Great help guys. I was thinking it was a throttle related problem alright but i wasn't sure if the computer was at fault. The car will be hooked up to a diagnostic computer at the weekend. I like the sound of gummed up throttle tho. Hope i'm on the right track!
@ le-dub - I have absolutely no intention of touching the engine myself. i was just hoping this issue had popped up before and i could get my mechanic to have a look at a soecific area instead of traoubleshooting himself and maybe getting the wrong diagnosis.

Thanks again everyone! I'll pop over to the Audi Forum for a look.

AMurphy

MunkyHed wrote:

Alright biys!
I'm having trouble with my car lately... anyone have any idea whats wrong with it. I havent a clue!
Its a 00 Audi A3 5 dr 1.6L
...
1. When i turn the key to start her up sometimes the engine won't engage, ....

2. While driving, sometimes the throttle takes on a life of its own. .....
Sorry for the long-winded post!
Any advice??
Munky

1; Does the starter simply spin freely or does the starter AND engine spin.
A free spinning starter is nothing rare, just needs either to have some parts replaced, lubed and cleaned. If the engine spins but does not start.. go to problem 2

2: this engine has a fly by wire throttle I'm pretty sure, so there is no cable to stick, but there is a lot of electronics to go haywire.

it could be sticking, a failing servo motor, bad electrical connections or a bad ECU (I hope not).
A spining engine and a sticking throttle could also explain the failure to start... ie it sticks closed on that occasion.

Start with a throttle clean and a recalibration if necessary.

MunkyHed

Thanks Amurphy, I'l let ye know how i get on over the weekend. She's going in for the day to the mechanic on saturday. Hope he catches the problem. I'll orint out all of your ideas on the issue and see if they can help him diagnose the problem. While the car is in the garage there'll be plenty of drinking done! Happy St Paddys day all!