[wfg97079]

Got a 2004 1.8t wagon with 120k on it
Seems that recently the car is vibrating more and more at a stop, most noticeable at a red light. Car in drive and foot on brake. Dont notice it when driving. Any thoughts?

Timing belt done about 20k miles ago

 

[ScottPassat2.8]

Either a vacuum line or cheapie axle was put on the car.

 

[V6er]

I would think it's time to change your engine mounts.

 

[wfg97079]

ah

Either a vacuum line or cheapie axle was put on the car.

I think the axel was done...that may be it.
There a way to tell if its that or the engine mount?

 

[saneeshd]

Engine mounts??

Is it ok with "N" and vibrates in "D"? Check your engine mounts and especially the front mount / snub mount.

 

[wfg97079]

I will have to check if its ok with N, Ill post that when I have it

 

[PZ]

It may also be something as simple as a dirty throttle body.

 

[doyles-1.8T]

Inspect the check valves on vac lines, mine is '04 1.8T and I have already had to replace 3 valves - rough idle smoothed out significantly each time.

Throttle body cleaning is probably good either way.

 

[jeanluc]

Clean the throttle body and do a throttle body adaptation. That fixed the rough idle on my car.

 

[wfg97079]

Correction, vibration completely goes away in neutral. What does that point to?

 

[wfg97079]

updates, anyone have any input?

 

[PZ]

Did you clean and adapt the throttle body and check the vacuum hoses, check valves and mounts yet? Any of them could cause this problem as could the cheap axles.

 

[wfg97079]

no

Haven't done anything yet, didn't know if the fact that it completely goes away when going into neutral pointed to something specefic

 

[jeanluc]

Where are you located?

I am still standing by cleaning the throttle body as a first step.

 

[wfg97079]

Mass

I am in northeast mass on the NH border. Ill look for a guide on cleaning the throttle body

 

[bvariant]

http://www.taligentx.com/passat/maintenance/throttlebody/

You can get away with replacing the old gasket, but a new one is dirt cheap and keeps you from wondering.

 

[scotts13]

Got a 2004 1.8t wagon with 120k on it
Seems that recently the car is vibrating more and more at a stop, most noticeable at a red light. Car in drive and foot on brake. Dont notice it when driving. Any thoughts?

Timing belt done about 20k miles ago

OK. In my experience, most 4-cyl automatic transmission cars do this they as they get older - the Passat is known for it; it's a common problem. Why is a little controversial. The most common diagnosis is bad motor mounts, followed by cheap axles, which makes little sense to me.

Now, IMHO, what we have is a complex situation, at least on my car it was. If the engine isn't running up to snuff, it tends to bog down and vibrate, as the drag of the transmission tries to stall it. So, anything you do for better running and less drag helps.

When I got my 2000, it had almost 180,000 miles and vibrated badly when stopped in drive. As I went through the car, changing air filter, spark plugs, cleaning the throttle body, cleaning the PCV system - each made a small improvement. Changing the ATF and filter made the biggest difference. Cumulatively, it now (at 236,000 miles) idles almost as smoothly as my 2004 (at 50,000 miles). Interestingly, one thing that didn't make a difference was replacing the motor mounts, which were in pretty bad shape.

For what it's worth.

 

[PZ]

Haven't done anything yet, didn't know if the fact that it completely goes away when going into neutral pointed to something specefic

Not really. It could be any one of those or a combination. To a certain extent, all of the engines vibrate in gear. Just start with the cheap stuff and work your way down the list.