1.8T k03 Wastegate flapper

[Major Tom]

Hi all,

I think I've diagnosed the stock k03 turbo on my 1999 GTI 1.8T with a busted wastegate flapper.

The actuator seems fine, no vacuum leaks coming from the hose, and the shaft isn't wobbling around freely to indicate the diaphragm or spring are busted.

I suspect the circular piece of the flapper inside the housing has dislodged itself (the car has done 256,000 mind you...) and is now causing the beautiful rattling noise coming from my downpipe/cat area. I have checked all the exhaust connections and mounts to nail down the source of the rattle.

I can hear the turbo spooling, but it drives as if it's N/A, so I'm thinking the flapper is gone and the turbo is spooling but not actually being able to generate any boost. I don't have VCDS or a boost gauge to verify this however, these observations are purely based on what I hear and feel driving it.

Have any of you guys experienced this before?

Thinking I may have to replace the turbo, unless I can get the flapper repaired somehow.

Any insight would be appreciated!

Thanks,

Tom

[Lito]

Hey buddy, I'd recommend taking off the dump pipe and visually inspecting the flapper. Depending on how it's failed (if it is the problem) you can weld the flapper back on but this would be a turbo out job and may not be cheap. I have a spare oem k03 that's gathering dust if you want it cheap? Let me know

[007]

Turbo spooling but no boost can be a busted wastegate actuator valve. They can be tested - the procedure is in the factory manual if you have one handy. The rattle could be in the Diverter Valve. I'd check both before taking the turbo out.

[Major Tom]

Lito - Hopefully tomorrow I can pull the downpipe off and have a squiz at the waste gate. All the symptoms point towards that being the problem. If so I'll take that K03 off you for sure.

007 - My DV is an uprated alloy one from Gavin, checked it and seems to me working as normal. Wastegate actuator also tested and working. The nuts are tight and spring tension also seems rock solid.

Poor little GTI sounds so rattley and weak

Unrelated question, do you guys have any recommendations for general use brake pads that are nice and low on dust? My rears need doing shortly also.

Thanks, Tom

[h100vw]

Lito - Hopefully tomorrow I can pull the downpipe off and have a squiz at the waste gate. All the symptoms point towards that being the problem. If so I'll take that K03 off you for sure.

007 - My DV is an uprated alloy one from Gavin, checked it and seems to me working as normal. Wastegate actuator also tested and working. The nuts are tight and spring tension also seems rock solid.

Poor little GTI sounds so rattley and weak

Unrelated question, do you guys have any recommendations for general use brake pads that are nice and low on dust? My rears need doing shortly also.

Thanks, Tom

Tom, I'd go and get pads off GSL Rallysport for the pads. I have Remsa ones in all my cars and rate them.

Does sound like a busted wastegate flap. Our A4 wagen had no boost when we bought it. Also had no nuts on the actuator rod

Gavin

[007]

For brake pads, these from GAP are the ones I'll be getting next.

[leighaus]

I also recommend GSL for brakes... awesome bloke.

good luck with your turbo issues.. interested to hear your outcome and costs!

[Major Tom]

Thanks for the advice guys, really appreciate it. Will do rear pads this week, although it looks like I'll need to buy/borrow a piston press tool for the rear calliper to get the new pads in?

Also, I just dropped the down pipe (3" aftermarket job) and sure enough, the lil k03 has no waste gate flap...

Lito, I will message you re your k03.

Leighaus yep it will be interesting, there's a few things I want to get fixed/sorted in the next month to get it back to 100%.

[h100vw]

Thanks for the advice guys, really appreciate it. Will do rear pads this week, although it looks like I'll need to buy/borrow a piston press tool for the rear calliper to get the new pads in?

Also, I just dropped the down pipe (3" aftermarket job) and sure enough, the lil k03 has no waste gate flap...

Lito, I will message you re your k03.

Leighaus yep it will be interesting, there's a few things I want to get fixed/sorted in the next month to get it back to 100%.

I have a wind back tool you can borrow.

Gavin

[Major Tom]

Radum Pty Ltd

Would that work Gav? Surprisingly affordable!

[h100vw]

Radum Pty Ltd

Would that work Gav? Surprisingly affordable!

Cheaper than the tolls to come to the airport for mine almost!

Gavin

[Major Tom]

Almost haha!
Once I get that Turbo of Lito's in the car I may pay you and your laptop a visit to get some numbers on how the car is running

[ryana89]

Radum Pty Ltd

Would that work Gav? Surprisingly affordable!

That's the kit I bought and used on my rear calipers

[h100vw]

Almost haha!
Once I get that Turbo of Lito's in the car I may pay you and your laptop a visit to get some numbers on how the car is running

Yeah, let me know. Don't reuse the copper washers on the banjo bolts!

Gavin

[Major Tom]

Yep, will replace gaskets, bolts/nuts and crush washers when I do it. Maybe even turbo inlet pipe.

Hoping to round up the bits by the weekend and get it done on Monday.