Tom10

Hello,

to start with, I have Audi A3 2005m, 2.0 TFSI, 147kw quattro , it had driven 107k km. More than a half of year ago, I changed diverted valve (it was broken) and did stage 1 remapping. After this step, car had around 170kw.

After few months I felt that some power disappeared. Took car on two dyno runs and both showed around 130kw.

All computer parameters are just perfect - turbo air flow, fuel mixture, etc, with no faults at all. What I did further, was leak down test, which did not shown any problems at all as well.

What I been suggested to do, is clear away first catalyst from the turbo, as it might be jammed or melted. However, this is only a suggestion and more of a guess, than 100% problem spot.

What I would like to hear from you, is whether there been such a problems already and how they could be solved? Since car is a quattro, there are quite a lot of work to get into that catalyst. Moreover, once it is cleaned, what would be needed to do with lambda probes?

Looking forward to your reply.

By the way, I have looked through search but did not found anything with the same problem...

Thanks!

Tom10

Here is how dyno test looked like.
(As you can see, chart is not evenly continuous...)


Hope this could raise a discussion of what might be wrong.. Whether it is catalyst or anything else worth checking? Thanks!

johnspd

Check the Turbo and all the connections to the Inter-cooler and off course 1st make sure you had the car properly serviced (Spark Plugs, Filter´s, Spark Wires if needed, Belt´s and Timing Belt if needed, Pulley´s if needed and last Gearbox Oil).

If anything of those doesn´t bring you the "Power" back see if you can plug an OBD II scanner and look for some Error Codes.

Don´t forget to Report Back,
Cheers

Tom10

All computer parameters are perfect and system is clean of errors (mechanics were amazed, that there isn't any of them after quite long period of time)

Spark plugs been changed before around 20000km, filters are being changed on every maintenance, timing belt before 18000km, with pulleys...

Currently, my only hope remains by checking catalyst and I am going to do that, because I do not have any other options to choose..

johnspd

My also be some problem with the Remap did you tried to do the process again, maybe getting the car back to Stock and then give it a try see what happens and then give it the "new" Map.

If this work let me know because I´m also finding very weird that you are getting that flotation on the top ranges (3k to 5k) but again could be a problem with the Fuel Pump that may be working too hard with the Remap which is showing some signs of wear/failing.

Tom10

Yes, I tried to reset it into original to see any sights of problem, with no luck. However, after this, I re-installed the same map. On Wednesday I am going to check catalyst and if this does not solve the problem, I will probably going to try other remapping service. Will keep this thread alive.

Tom10

Both catalyst been checked and shown no problems at all:




Do you have any more ideas to solve this problem? What else could be checked, reviewed?

smooth 1

Have you looked at the blow off valve and waste gate? Look for leaks and or weak spring? I'm wondering if you getting to full boost..even as low as the stock setting is..if its 10 psi,,and your only getting say 6 or 7 psi...

Also...have you checked the PCV valve? If that fails it causes a back pressure in the block that drops the power output.

Tom10

Hello guys,

I just realised that I haven't explained the causes of this problem.

A3 quattro has a Haldex system, which as a result was somehow causing the issue. Accordingly, the Haldex been malfunctioning and at the same time affecting the power outcome (maybe blocking ECU in some way, I do not know).

Overall, the Haldex oil pump was defective, and after replacing it, problem resolved. However, some time after that 4WD system broke completely and I was driving on 2WD only. Replacing whole rear diff with Haldex unit solved the issue 100% and the car got back into its initial state.

Change the oil and filter in the Haldex as frequently as it is required in the manual. Totally worth it, instead of changing the whole unit.

turbo510

Evidently fuel gauge problems are common after fuel pump replacements, and post #15 leads to the solution, at least in my case. There is a hard, formed plastic tube attached to the underside of the white plastic tank cover, over the fuel pump. This tube can interfere with the level sender arm unless it is installed correctly, and mine wasn't. The tube fits through the hole in a small funnel shaped part of the pump's mounting frame. The pump does not need to be removed, just lift the tank cover with hoses and wiring attached enough to maneuver that plastic tube into the funnel. That fixed my gauge problem.