TDI Turbo Power Loss (solutions and did not fix only)

Have you fixed the power loss issue?

  • Yes

    Votes: 3 37.5%
  • Still working on it

    Votes: 5 62.5%
  • Given up

    Votes: 0 0.0%

  • Total voters
    8
I know there are lots of posts about this but there very messy. This post is to post solutions and work carried out that did not fix the problem ONLY. Please dont spam with speculation.

I have this issue and changed hoses and the MAF but the problem is still there although I only lose power around 85 MPH now which is better than 60 MPH which is where it started. There are NO error code faults found so im working blind on this but will keep you posted.

Andy

P.S when updating your post please EDIT your old one to keep this clean.
 
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Split intercooler replaced by non audi garage now working splendidly. Happened after 130K Miles cost was £450 including VAG diagnostic
 
Help, I am being ripped off by my garage

I have an AUDI A3 TD1 130cv from 2001 with 70k miles. After 20 miles on the motorway, I have a big power loss at every speed. This diseappear when I switched my car off.


Since March my Audi garage is trying to fix the issue.
At the beiginning, they think it was a problem with pressure sensors which they changed. As the problem was still there, they think it was due to hose adrift at charge air cooler, which they refitted.

As the problem was still there, they changed entire hose, valve and pressure converters. It did not solve anything.

Now I am being told that I need to change the turbo for £1700, after having already spent £800.

I do not what to do. I do not really trust them anymore because their diagnostic has been constantly wrong. I imagine the worst: changing the turbo and still having power loss!!!
 
Hi Dave78, welcome to the A2oc
We have no expertese with A3's on this site but some of the charge air system problems from our A2's should read across to your car.
Two possible causes of your engine going into 'limp home mode' are a split aftercooler core or a sticking variable vane mechanism in the turbo
On A2's the aftercooler core can split around the end covers but the split only opens up and leaks air pressure at higher boost levels. As the engine ECU is continually monitoring signals from the MAF sensor and manifold pressure sensor, it identifies a mismatch between the airflow going into the turbo and the boost pressure after the turbo and triggers the reduced power 'limp home' setting.
I assume your 130 hp engne has the variable geometry turbo. The moving vanes within this turbo optimise low and high speed airflow so when they stick the turbo may produce less boost than required. This again would trigger the limp home setting. See this link, particularly the last animated picture, for more info on sticking turbo vanes - http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html
Switching off the engine resets the ECU and everything is fine until the engine is worked hard again and turbo boost is lower than the engine requires - for whatever reason

Hope this helps Spike
 
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I know there are lots of posts about this but there very messy. This post is to post solutions and work carried out that did not fix the problem ONLY. Please dont spam with speculation.

I have this issue and changed hoses and the MAF but the problem is still there although I only lose power around 85 MPH now which is better than 60 MPH which is where it started. There are NO error code faults found so im working blind on this but will keep you posted.

Andy

P.S when updating your post please EDIT your old one to keep this clean.


Not sure if you've sorted your problem but I wanted to express my extreme thanks to this forum for it's invaluable help in solving the same issue I had and share some of the steps that got me there. Bit of background: I bought what looked like a nice spec 2001 Silver 1.4TDI (75BHP) from a guy that turned out to have pulled the wool over my eyes about a couple of issues the cropped up as soon as 30 mins after I picked up the car. Of course he pleads innocence and will hear nothing of a return for a refund or contribution to repairs (so far). Long story, I was saddled with (amongst many, many others) the limp mode problem when putting my foot down in 4th or 5th on the motorway, usually around 3000 - 3500 rpm when accelerating to join the traffic flow (just the point where you least need a drop in power, eh?). I spent hours (days?) and money on solving this, so I'll share the areas that this forum has kindly pointed out to check and then indicate what my specific problem was:

1. Get a code reading (this is important - don't waste your time and money until you at least have an idea of where the fault might lie. I spend more money than I should at my garage so they were obliging to read the error codes on my car for free. I had one related to the cam shaft and boost pressure. Replaced cam shaft sensor (easy job on the 1.4TDI) but problem persisted)
2. Vacuum hoses from N75 relay at front right top of engine bay - checked for splits/leaks. Replaced some of the obviously worn pipes, but found no specific splits. Problem persisted)
3. MAF sensor - Didn't check this, didn't see it called out as a common related issue. I think it will be accompanied by an engine warning light on the dash, which I didn't have)
4. MAP sensor - Replaced this with a Bosch original that I managed to find for £30 at a friendly local parts store that ordered it in same day for me. Beat eBay, local VW and local parts store change both in time and at 50% of the price or less! But didn't solve the problem
5. Intercooler - this is at front left of radiator. Checked this for splits or oil leaks, but looked 100%
6. Checked large turbo air pipes to head and from intercooler and to and from exhaust manifold for leaks, found nothing obvious
7. Fuel filter - was recently replaced
8. Took out the heat shield above the CV joint to get a better view of the turbo. Saw more oil on and around turbo than I expected and pipe leading from intercooler into turbo looked a little loose. Checked where the vacuum pipes run into (out?) of the turbo and found (more by feeling than by sight) that one of them had completely popped out (there are two) and the rubber hose at the attachment point had stretch so it was no longer a tight fit. Also removed the air intake pipe mentioned above and found the o-ring had perished (cross section was square not round any more and rubber was hard). Replaced this and re-fitted pipe. Test drive - SUCCESS!
9. If none of the above are the problem, it might be the Turbo. If you have a variable vane turbo (not on the 75BHP 1.4 AFAIK), check that mechanism for movement.

I think that is about it, hope it helps someone!
 
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