TDi90 possible turbo problems?

Hi,

I've had a look through the other threads about the turbo on the TDi 90 but the issue I've got isn't quite the same.

I purchased a 2005 TDi 90 a week ago (04-07-2010), FSH, 71k on the clock. Before buying it, took it for a test drive and immediately noticed what I believe to be an air leak somewhere around the turbo.
There's no noticable power loss from what I can discern, however having come from a 2001 TDi 75 which has done 154k miles (and is now at a salvage yard due to a careless driver who turned into me without looking), the engine noise when you take it from 2100 rpm in 4th & 5th upwards appears to be much louder than I would have expected.

We took the hood off and had a listen when standing and there is what sounds like air leaking from somewhere in the upper left quadrant of the engine compartment.

Not knowing exactly what I'm looking for, nor knowing anyone personally around the North London area who I could ask to have a look, is there anything a luser (me) can do without much disassembling?

Also, when the climate control is actively cooling, there's a knocking sound... any theories?

Thanks!

Aaron.

Hi Aaron

Sucking Noise -
The MAF (mass air flow sensor) is in the top left corner of the engine bay (see pic in thread below) Check the pipes and hose clips which run from the air cleaner to the MAF and from the MAF to the turbo for splits and leaks.
The air cleaner is located roughly below the drivers side headlamp.

Knocking Noise
Check the aircon compressor is not loose
Check the compressor pulley for damage as it incorporates a rubber drive mechanism which can fail

Cheers Spike

http://www.a2oc.net/forum/attachment.php?attachmentid=1687&d=1215546379

Cheers Spike,

I'll take her lid off tomorrow and have a look.

The vacuum pipes for the turbo and other valves run around that area to so you'll prob want to check them too

John

I've had a poke around and can't visually see anything wrong (loose clips, etc)

Took some photos of the inside, perhaps someone could stick some arrows on them so I know exactly what I'm supposed to be poking






Thanks,

Aaron.

I now have the Intercooler pipe ready to fit!

Whilst I was waiting I thought I would do some other bits.

Please note. This is a hard job to do and not for the faint hearted. You have to be a gynecologist type mechanic as it is very tight up the back side of the engine. You need the right tools and a lot of patience.

I started with the Actuator removal and clean up. It was quite sooty (See Pics).

Next was the manifold and ERG Valve. Both were kinda bad.
I thought I would clean these parts first before going any further.
Cleaning the manifold took me all day! I cant tell what a sh*ty job this is never again! It was like Tar. I burnt it out several times with a blow torch, two cans of carb cleaner, several washes with alloy wheel cleaner, Dremel to remove lumps of bad casting inside and finally wet and dry.

I bought a blanking plate of eBay to blank the bottom of the ERG when I put it back together.

Ok the biggie. Turbo

Took me ages to remove, I whacked myself in the eye twice with a block of wood pushing the engine away from the back wall, but it did come out.

Pretty clean but on the air intake a couple of small nicks in the fins (see pics).

mmmmm what do I do? I remembered someone in another post mentioned Turbo Technics in Northampton. Gave them a ring for some advice.

The Bad News!

They say the KKK Turbo is particularly weak turbo, if the turbo had a whistle, witch it did after my visit to Stealth, plus the nicks on the fins throwing it off balance. It is possible on its way out.

The Good News!

They can service it! Replace or repair the damaged spiny bit. Replace the bearings with upgraded high performance ones and clean the variable vane mechanism for a cool £240+VAT.

I get worried about turbos as my dad has a VW Sharan 1.9TDi with 25,000 on the clock, Yes only 25,000. Like NEW and the mileage was all done driving to spain. Last year he got as far as the middle of France and his turbo blew-up sending parts into the engine and that was it. gone! He ended up having it shipped back to the UK as the those Frenchies wanted a £6000 to fixit Yes I said £6000 what bunch of rip off French surrender monkeys. It still cost him £2500 for another engine, New Turbo and labour.

Hopefully all this work will save me money in the long run!

More Pictures

acolwill said:

I've had a poke around and can't visually see anything wrong (loose clips, etc)

Took some photos of the inside, perhaps someone could stick some arrows on them so I know exactly what I'm supposed to be poking

Thanks,

Aaron.

Click to expand...

Hi Aaron

There is no common weak point on the intake system so its a case of checking the air cleaner housing and all the pipework, between this and the turbo, for leaks.
The fact you don't have a low power problem suggests there is no issue with loss of turbo boost. That's why I suggested you concentrate on the intake system rather than look for leaks in the aftercooler and related charge air pipework.

Cheers Spike

I'll take her apart again on the weekend. Not enough light around when I'm back from work to have a proper look :|

Start by removing the large bottom pipe from the intercooler rad, near the air filter. Thats was where my split was. You could only see it once it was removed.

Darren

Right!

I've done some comparisons with another A2 TDi 90, and the results are nigh on identical.... There's the same throaty sound when you pull away in the upper gears from ~1750 rpm till the turbo kicks in at around 2150-2200rpm.

Without having a base reference to compare against, nor having the proper tools to start ripping apart my air intake system, I've come to the conclusion that this is a common sound on TDi 90s!

I guess only other A2 owners who themselves have TDi 90s will only know if what I'm saying is baloney or not (Mike!).