5spdJunkie

'97 1.8Tqm - chipped

I've been working on what I thought was a boost leak for about a week now. under boost conditions I hear a loud air sound coming from under the hood. the sound starts to fade out around 5300 rpm and is almost gone by 6000 rpm.

no CEL and the car seems to run fine, just under powered. power loss seems concentrated at the lower rpms. acceleration from 50-80 I think is alright. the car doesn't FEEL as fast, but the needle moves about the same.

I made myself a pressure tester and found an inch long gash in one of my vac hoses. I thought surely this was my problem so I replaced it, but the sound is still there and just as loud. it also made little, if any difference in performance.

I've been running the 710N diverter valve for about 10k miles so I don't think that's the problem.

haven't checked many hoses on the turbo side because they are crimp clamped on. don't really know how to deal with that.

Speedy72t

you need to hook up a boost gauge to see what kind of boost you are getting. It could easily be the 710N valve has failed again. try another, there cheap.

TighTT

I have personally ripped through 2 of those valves in my A4. All the TT guys dump them right away. Go with a nice hyperboost and you'll be very happy....almost no chance of failure. I would say that your problem is a boost leak....not a dying turbo. The fact that it happend at lower RPM or "under load" suggests that its a leak.

Octane

yup sounds like you have a crack or blown hose...time to really start inspecting.

Joey T

Yes, you can unclog a huge **** blockage in your toilet with just your hands, but really, wouldn't having the right tools be better?


Buy theself a boost guage.

If you cannot afford one,come to my house. We will take mine out and install it on your car.

Then we know what you have for boost.

Again, I ask.. have you ever heard any wastegate rattle?

Justin517

witht he car off the waste gate should be tight (its spring loaded) and shouldnt rattle or wiggle around at all. if it does its shot, dont just replace the actuator, more likely than not the flap itself os shot and there are probably cracks in the housing, mine was this way at 76,000 miles when i bought it. but dont get down about it, it may not even be that, may just have a leak. buy a boost gauge and build a pressure tester (seach, they are easy). and best of luck!

5spdJunkie

checked the actuator rod, it's tight.

I built the best pressure tester I could come up with. attached it to the hose that connects the crosspipe to the intercooler. with that I found a torn vac hose, but as I said in my post the problem persists.

incidentally, I searched for "pressure tester" and got no hits.

5spdJunkie

never heard any wastegate rattle. tried to jiggle the actuator and it wouldn't budge.

I'm confused, did you ask me before about wastegate rattle? as it stands I can't really afford a boost gauge anymore than I can afford anything else I'd like for my car. but then if something is broken I have to nut up and fix it.

as for fitting my car with your boost gauge I appreciate the offer, but judging from your picture poster you don't live anywhere near me. I 'm in the Dallas/Forth Worth area of Texas.