Okay, so just today while driving I noticed my turbocharger seemed to be not kicking in quite as hard. Usually I can feel some noticable ummph around 2200 RPMs and it continues to 4k. This morning there was some audible spool up at the normal RPM, but it sounded louder and more like a dentist drill. I have been known to overworry things, but I'm pretty sure this is the bad sound you don't want to hear. The turbo spools up, but you don't feel the boost. Worse, the boost seems to drop a little around 3k. In third gear this was most evident, the car felt sluggish and heavy. I did just fill the tank (it was nearly empty before) but it feels much different than just some fuel weight. So here is what I have determined to be possible causes: Advise me please.

1. Either one or both of the vaccum lines that connect to the intake manifold are leaking. The closest is the charge controller line and connects to the wastegate. If this line is broken, the turbo will run at 5psi, not 8. The further is the fuel pressure line and controls the amount of fuel the injectors pump. A leak here causes the engine to run lean.

2. Shaft play. Not the good kind you get from your girlfriend either. The previous owner had no idea you needed to warm up and cool down a turbo. He also used some weird green coolant and the oil is pretty low. Tomorrow I am flushing the coolant and adding oil. All these problems combined could have possibly caused this 80k mile turbo to start to die right?

Some other questions, if I do have bits of my turbine in my intercooler and intake, would I be able to hear it rattling around? What turbo upgrades do you recommend to a highschool student with a limited budget if (knock on wood) the turbo is failing. I probably want to skip the k04 as it doesnt provide as much bang-for-buck, but how much do elim kits require modification and upgrades to engine? I really would like to stay plug and play.

Thank you B5 forum! Don't let me down!

 

its possible your just in limp mode, or at least you should be hoping for that. im sure you would have posted it, but you got any codes? if your flushing coolant and adding oil tomorrow you should take off the turbo inlet hose and check for shaft play while your in there. the fact that your low on oil could mean the turbo is on its way out and burning the oil while its at it. notice any kinda color to the exhaust?

 

I haven't noticed colored fumes, but the exhaust was done very unprofessionally. It leaks and its possible there are so few fumes coming out the tail that I don't notice color. I'm taking it to a shop to get flushed, should I have them check for play or is that something I could do with minimal deconstruction of the front clip? No CELs or anything, though I didn't VAG-COM it. Last scan was yesterday afternoon while removing ABS module for a rebuild. Nothing unusual came up. Random misfire. Cleared it and it didn't come back.

 

explain limp home mode to me though, I've heard about it.

 

scaled back boost and timing. basically its your cars way of attempting to protect itself if it notices something is wrong. really only happens when you get a cel.

 

yeah, no CEL. I seafoamed it about a week ago and used the charge controller port to introduce seafoam to intake. I used a third can. That along with 1 can in the gas tank gave me a CEL. I've since used up all that seafoam/fuel mix and refilled the tank. CEL went out a day after seafoaming. I don't think its related. Whats possible is that while trying to slip the vaccum line on and off while keeping the clamp on I may have damaged it.

 

Bump.

 

How many miles are on the car? Not to be a debbie downer but ive heard that when the turbo sounds like "a dentists drill" it usually means its on it way out. Do you have a boost gauge, if so what are you boosting at?

 

No gauge. Car has 170k. Previous owner said turbo was replaced at 90k, which would put it at 80k right now. I really hope its not on the way out, but he did put in the wrong coolant, (which I'm gonna flush), had low oil, and knew nothing about warming up or cooling down the turbo. I think I'm going to start by disconnecting the negative cable on the battery for a half hour to try and reset everything. I hope its possibly in Limp Mode. I just recently removed the faulty ABS module, it was burnt out and not communicating, but maybe just having it out put the car in limp. Next I'll probably replace all or most of the vaccum tubing lines and check for shaft play. I plan on making my vent mount and getting a gauge soon, so we'll see how this pans out.

 

today during a normal drive home in my 1999 a4, i felt a sudden change in the rate a which the car accelerates, and i also heard the dentist drill sound that you were describing. i am just wondering if you ever got it fixed, and what the problem was and if you got it fixed how much it cost.