Car shake

**neodhanjal** · 05-02-2008 08:00 AM

Hi Guys,

Complete noob here...just hoping you guys can help me narrow down what the problem might be:

I have a A4 B6 1.9TDi (the 130 one) with around 78000 on the clock

Now when I start it, the car has a slight shake when idle. Its not steady, but more like a pulsing shake...car becomes steady and then shakes again - this happens in a cycle of around 5-6 seconds between shakes. Its very slight but very annoying.

It happens wether the car is hot or cold...doesn't seem to make any difference. I've changed the air filter, timing belt was done not so long ago but apart from that i'm outta ideas...

Someone mentioned it may be the glow plugs, but 1 - can't actually find where they go (removed top cover and just have no clue) and 2 - thought that if the issue remains after the car is fully warmed up, it normally isnt plugs.

All help appreciated.

Thanks

**audipotential** · 05-02-2008 08:10 AM

Originally Posted by neodhanjal

Hi Guys,

Complete noob here...just hoping you guys can help me narrow down what the problem might be:

I have a A4 B6 1.9TDi (the 130 one) with around 78000 on the clock

Now when I start it, the car has a slight shake when idle. Its not steady, but more like a pulsing shake...car becomes steady and then shakes again - this happens in a cycle of around 5-6 seconds between shakes. Its very slight but very annoying.

It happens wether the car is hot or cold...doesn't seem to make any difference. I've changed the air filter, timing belt was done not so long ago but apart from that i'm outta ideas...

Someone mentioned it may be the glow plugs, but 1 - can't actually find where they go (removed top cover and just have no clue) and 2 - thought that if the issue remains after the car is fully warmed up, it normally isnt plugs.

All help appreciated.

Thanks

Why dont you just change your spark plugs. Shouldnt cost more than 20 bucks. Im willing to bet your gap is screwed up.

Take your coilpacks out and there they are

**pondside36** · 05-02-2008 08:26 AM

If I read your post right, you have a european diesel A4, so no spark plugs... does it vibrate after you drive and then come to a stop at idle?

**neodhanjal** · 05-02-2008 08:54 AM

Originally Posted by pondside36

If I read your post right, you have a european diesel A4, so no spark plugs... does it vibrate after you drive and then come to a stop at idle?

Yup...no plugs...just glowys

Yup...I can drive off and everytime I hit a set of lights and stop, the shake will still be there.

Someone just let me know that maybe it could be my EGR valve? I noticed that it has got a lot of soot and oil around the main valve area...should I give it a clean? Any FAQs on how to do this?

**pondside36** · 05-02-2008 09:00 AM

I work on marine diesels so your car is new to me and most of us on here are driving Gasoline engines... what is the ERG valve? I was thinking since you were running a diesel a little warm up time would take the valve train vibration away, ie valve lash but you may have or probably have hydraulic valve lash adjusters.

**neodhanjal** · 05-02-2008 09:14 AM

Originally Posted by pondside36

I work on marine diesels so your car is new to me and most of us on here are driving Gasoline engines... what is the ERG valve? I was thinking since you were running a diesel a little warm up time would take the valve train vibration away, ie valve lash but you may have or probably have hydraulic valve lash adjusters.

Exhaust Gas Recirculation valve...

Don't really know wat it does...but supposedly it can get dirty and choke your engine a bit.

As for the shake...it should go away...every deisel I've driven it has always gone after the initial warm up...but on my a4, just seems to stay...

**pondside36** · 05-02-2008 09:16 AM

Ok, so a EGR is an Exhaust Gas Regulator used to recirculate excess exhaust gas back to the intake, interesting, and it is at its greatest recirc rate at idle. With that being said you might be right with cleaning the EGR if the valve seat is all gummed/sooted up, it may be sticking. Or perhaps the ERG is failing and not opening as it should since the pulsation vibration you are feeling. Perhaps a trip to a mechanic who can VAG it may be in order.

**neodhanjal** · 05-02-2008 09:25 AM

Originally Posted by pondside36

Ok, so a EGR is an Exhaust Gas Regulator used to recirculate excess exhaust gas back to the intake, interesting, and it is at its greatest recirc rate at idle. With that being said you might be right with cleaning the EGR if the valve seat is all gummed/sooted up, it may be sticking. Or perhaps the ERG is failing and not opening as it should since the pulsation vibration you are feeling. Perhaps a trip to a mechanic who can VAG it may be in order.

Sounds like a plan...will do that over the weekend and report back.

**pondside36** · 05-02-2008 09:29 AM

Good luck... and please don't just start taking things apart with out consulting someone more familiar with your engine like a mechanic. There is likely gaskets and what not involved that may need to be changed if you remove that valve.

**audipotential** · 05-02-2008 09:53 AM

Oops so used to seeing 1.8, I didnt even see it was 1.9

**bavaria75** · 05-02-2008 10:13 AM

Just my 0.2 cents.
Is the engine checklight on?
Maybe the O2 sensor is faulty and makes the engine un-smooth?
Do you have a higher gas usage? (MPG)
Does the Powersteeing pump (You steer) or AC compressor (switched on) kicks in?

**kwimberly** · 05-04-2008 10:35 PM

I used to have the same thing in my Jetta. It needed a throttle body realignment because I had disconnected the battery. I could see the RPMs go up and down every few seconds.