Hello everyone,

I have a 2001 audi a4 1.8t that is shaking occasionally.
It started off pretty bad, the shaking would come from the front end, i did all the proper procedures, (new coil packs, spark plugs, and i even put a fuel system and intake cleaner in the tank) with each step i took the shaking went down and got a little better, it even stopped for a week when i put the fuel system cleaner in, but now at this point it is starting to shake again occasionally and im starting to think it's more of a fuel system problem rather than anything else. It shakes occasionally with a full tank of gas but the less gas i have the harder and more frequent it shakes.
Any advice on what it could be?

 

If you think it's fuel related, have you changed your fuel filter?

Doug.

 

Do you have or have you seen a CEL (check engine light)? If not it's possible there are still fault codes stored which may help toward diagnosing this issue.

I agree with the fuel filter replacement option. Even if it doesn't solve the issue, it's still a good maintenance item.

It may also be air related - you can try unplugging the MAF and drive around. If the shaking it bad this could indicate a failing MAF sensor and/or an air leak. If it's air related, my bet would be on some ripped hose or damaged check valve causing an air leak.

 

That's what I was thinking I was gonna check the MAF and in regards to the CEL it's always on (that's how it was when I bought the car) but sometimes when the shaking gets worse the CEL starts blinking

 

1. Fuel filter
2. Seafoam,
3. Clear codes
4. Dump your favorite, one time "Complete" fuel system cleaner into your tank (after the filter R&R).

In that exact order.

All cheap and easy to DIY.

 

The flashing CEL means you're actively misfiring - did you verify the proper gap on your plugs as well? Most plugs come pre-gapped but could be wrong. You want .032" if stock and .028" if you have a chip.

 

You said fuel filter is DIY? Any walkthroughs or threads explaining how to change it? And with seafoam which product should I use?
Thank you so much for the help. I'll try this before having to try the expensive fixes haha

 

I gapped them at .029 should I increase the gap a little?

 

NP

Your car is the same as mine ('01 1.8t) and I've done my fuel filter. It's really easy. It sits under the drivers door and when you look at it, you'll know exactly what you need to do. If not ask for help and I'll walk you through it.

With Seafoam, use "Seafoam" (that's the product's name). Read the directions well.

After that, buy some "Lucas upper cylinder lube" and follow the directions on that as well.

G/L w/everything.

 

will be doing this tomorrow ill let you know how it goes thanks for everything!