Through reading various posts on this forum I believe I have been able to diagnose the issue that I am having but I want to be certain before I get into troubleshooting and repair work. I'm in a stock 03 Passat 1.8T. A few days ago I noticed I couldn't hear my turbo spooling up but I could hear the blowoff valve which seems to be blowing off anytime I touch the gas at all. I also have very little acceleration power now I am guessing due to the lack of functioning turbo. As an added bonus when all of this happened my ABS and Traction Control warning lights started intermittently coming on and now my idle is extremely rough until the car warms up to 190. I am assuming from what I have read that this is due to a boost or vaccum leak. Any assistance in pointing my in the right direction to get this little murder of crows taken care of would be appreciated.
Need some assistance with a diagnosis.
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For starters, you don't have a blowoff valve, you have a diverter valve. Instead of dumping excess boost pressure, it recirculates it into the intake. If you're hearing a whooosh, you almost certainly have a large boost leak. Your symptoms are compatible with, say, the pressure hose popping off. Take a look.
That makes me feel a little better. As for the pressure hose I've never owned a turbo charged car before so this is all foreign territory to me as far as repairing goes. When we replaced the turbo on the car after I got it, it took about 12 hours because we had never had to work with a turbo before then. Exactly which hose do I want to look at?
I wasn't able to find a diagram of the components on the engine, but this should help - until you buy your own copy of the Bentley manual. 9, 14, and 17 to start.
![Line art Text Organism Design Illustration]()
1. Intake Hose
2. From air filter
3. From EVAP canister
4. From crankcase ventilation
5. To turbocharger
6. Pressure regulation valve
7. Connection hose
8. To throttle valve control
9. Connection hose
11. Charge pressure sensor
12. Intercooler
13. Duct
14. Connection Hose
15. From turbocharger
16. Transverse pipe
17. Connection hose
18. Vacuum line
19. Deceleration shut-off valve
20. Elbow
1. Intake Hose
2. From air filter
3. From EVAP canister
4. From crankcase ventilation
5. To turbocharger
6. Pressure regulation valve
7. Connection hose
8. To throttle valve control
9. Connection hose
11. Charge pressure sensor
12. Intercooler
13. Duct
14. Connection Hose
15. From turbocharger
16. Transverse pipe
17. Connection hose
18. Vacuum line
19. Deceleration shut-off valve
20. Elbow
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You could do a boost-leak test to help find any leaks in that intake path.
boost leak test - Google Search
boost leak test - Google Search
I checked the indicated hoses from the diagram and all of them are firmly in place which leads me to believe there is probably a hole in one of the lines. I am going to do something along the lines of this video.
Thank you both scotts13 and Steve in Chicago for your replies. While I am pretty confident in working on pretty much any other aspect of a car I am a noob in the world of turbos.
Thank you both scotts13 and Steve in Chicago for your replies. While I am pretty confident in working on pretty much any other aspect of a car I am a noob in the world of turbos.
Something similar happened to me once with our '99, perhaps after removing the turbo to repair the waste gate flapper. On the test drive, first application of boost was followed by the noise of major air discharge, and little power. It didn't take long to find the cause: The plastic pipe leading from the DV back into the rubber turbo duct had blown off, due to me not clamping it on. A few minutes later, it was all good.
So to update. The problem has been solved. I just haven't had the chance to post about it due to overtime at work.
The first step I took was to create a boost leak tester which I was able to assemble with about $30 in parts from Home Depot.
![Gauge Measuring instrument Tool]()
After hooking it up to an air compressor I was able to quickly identify the source of the leak. The lower inlet on my air mass meter hose had ripped.
![Pipe Auto part]()
The part cost me $29 and took about two hours to put on.
Again I really would like to thank everyone who replied here and helped me get this problem taken care of.
My B5 runs better now than before this problem cropped up which leads me to believe that when I got it the inlet was already starting to tear free.
The first step I took was to create a boost leak tester which I was able to assemble with about $30 in parts from Home Depot.
After hooking it up to an air compressor I was able to quickly identify the source of the leak. The lower inlet on my air mass meter hose had ripped.
The part cost me $29 and took about two hours to put on.
Again I really would like to thank everyone who replied here and helped me get this problem taken care of.
My B5 runs better now than before this problem cropped up which leads me to believe that when I got it the inlet was already starting to tear free.
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