well my boost guage is acting up up. its a vdo that was installed prolly 20k ago. The thing just doesnt suck vacuum like its used to. would easily go down to 25 in hg. it goes down to 10 in hg now and very slowly works its way down to 20 in hg. but the kicker is it doesnt read boost very well either. it used to jump right up to 25 psi in fifth (im st chipped). it still spikes like that but now it sits at 0 psi, wont climb very well, then all of a sudden jumps to the boost reading. anyone have problems with a mechanical boost guage like this or is it a vacuum leak? car runs fine otherwise and feels the same driving it.

 

I cant imagine you could have a boost leak that big and have it feel no different when driving. So I would have to say its either the gauge itself or check the line going to the gauge.

 

You're sure it isn't a boost leak? 'Cuz all of those symptoms could describe a boost leak LOL.

If you can hook up its pressure line to a known vacuum or positive boost pressure source then you can check its functionality. I suppose it's possible some gunk made its way into the gauge's internal components and that is causing the reading to be off.

 

im pretty sure its no boost leak. the guage seems to work fine while boosting, just a little choppy. it just wont read vacuum like it should. and like i said the car drives just fine. id probably notice a boost leak that big. but i also have a hard time believing the guage went bad. do you think if i spray some break clean or contact cleaner in the guage it might help free it up?

 

I think it should be okay to spray a plastics-safe degreaser into the vacuum port on the gauge, and let it soak before spraying out as much of the crap as you can.

Have you done a boost leak test? Might be a silly test, but I've been surprised plenty of times after performing it...

 

Sounds like a boost leak to me..I had the same problem on my 2003 A4.


Easiest and free way to do a boost leak test was this site ->>http://www.younanplex.com/engine/car...t_audi_tt.html


Hope this helps. If the link doesn't work here the direct link

http://www.younanplex.com/engine/car...t_audi_tt.html

Cheers..

 

Ha a little late on the help but thanks. Turns out it was the gauge. I just sprayed some brake clean in the port of the gauge and it works fine now. Vacuum reading back down to 22 in hg.

Edit: just realizes this guy is probably a spammer. Don't click the links

 

Sorry didnt look at the dates...kinda new to the forum. Glad to hear you got it fixed. But how am I a spammer?! I had similar problems on my car and the site gave me ideas on how to get it fixed.

 

We get spammers alot on this site and they usually resurrect old threads and only have a couple posts. So you ot really seemed likely you could be a spammer. Glad to hear you arent