Still can't figure out where the vibration is coming from

[midnightblue328]

hi guys,

I need some suggestions on what to work on next to fix a problem I’ve had for a while
I feel some vibration on the steering wheel when the car is idling. I changed two tension pullies, all four oxygen sensors, engine mounts, transmission mounts, both belts, cleaned the icv, poured acetone into fuel tank to clean the injectors, and I still feel the vibration in the steering wheel.
The vibration is stronger when the automatic transmission is in drive or reverse, but I still feel some vibration when it’s in neutral. The idle goes as low as 600 rpm when the transmission is in drive or reverse, and fluctuates around 700 when in neutral. When I’m stopped and shift the transmission from drive to neutral, the rpm dips 500 or so and comes back up to around 700.
I didn’t have the vibration or this idle rpm fluctuation when I bought the car couple years ago with 80,000 miles on it. Now it has 110,000 miles on it but I want to bring it back to the condition when I bought this car.
Can any one suggest what to fix next to see if I can solve this problem?

Thanks in advance,

[SCANDINAVIAN13]

Check trans.
Check the trans fluid level and or replace the fluid.

[Bimrpwr]

so it just vibrates when you are sitting still? or is it just when u are moving?

Have you tried to change your plugs, air filter?

Try to run some BG44k through a tank and see what happens?
Maybe you keep buying some bad gas as well. Try a different place or higher octane. it may take a couple of tanks to help out.

[midnightblue328]

Thanks for the suggestions guys,

I changed the trans fluid couple of month ago so that might be a good place to check back.

The vibration is only when I'm idling. No vibration while driving, or at least I don't feel like its vibrating.

I did change the spark plugs, and as far as my research tells me acetone is one of the best cleaner of injectors.
What acetone did was to increase the milleage by about 10%.

I'm using the highest octane gas available so don't think thats the cause,
but I'm thinking about trying the moss balls to boost the octane and see if it helps.

I do feel like the idling is a little low.
I also do have the engine coolant level check showing up when I start the engine, but it goes away in about 15 seconds.

Should I try replacing the engine coolant level sensor and engine coolant temperature sensor.

Any suggestions are welcome at this point.

Thanks in advance!

[SCANDINAVIAN13]

The coolant sensors won't fix the idling issue, though it may fix another issue.

Check your air filter and have your injectors checked.
"An injector that shorts to ground will remain open constantly when the engine is running, creating a rich air-fuel mixture that can dilute engine oil, foul the spark plugs, cause a rough idle, and damage the catalytic converter."

[midnightblue328]

Hi Kyle,

Do you know how I can check the injectors? Is it something I can do my self?

I've already ordered the airfilter so I should be able to change it this weekend to see if that makes any diferently.

Thanks,

[SCANDINAVIAN13]

I'm not sure how you'd test them yourself. I'm sure a mechanic could check them out, but I'm sure you could get some sort of reading if you take a volt meter and test the ground connection. I'm not sure how you check for shorts. Check Google out.

This might help:
http://www.jambolnet.com/stoian/Audi_A4_B5_97-2000/Fuel%20injection%20and%20ignition/AFC/MFI/24-29%20Fuel%20injectors%20checking.pdf

It's for an Audi, but electricity is electricity. You just need to see if there's a short to ground, however you do that.

[midnightblue328]

Hi Kyle,

got the instructions and they look totaly DIYable. I'll see if my friend has the necessary tools in his garage. If not, as you said, a mechanic can check it for me.

Thanks

[drivinfaster]

didn't know that you could get moss in a ball form. however, if you were talking about 'moth balls', don't do it. it doesn't work, and could produce some nasty results. stick with the proper fuel additives (like the bg stuff).

as for checking the fuel injectors, you could buy a tool to do a static flow test. it would be used in conjunction with a fuel pressure guage, and will be able to show you any diference in the anount of drop in the fuel pressure when doing this test.

you could do this, or like a previous post, check the trans fluid level and condition. maybe even have a trans shop take a look at it and see what they think, because you seem to have covered all of the obvious concern areas already.

good luck with this.



drivinfaster