Low BHP, re-cond. turbo

[nattyboy]

Hello all,
After having the turbo re-cond on my 2004 A4 1.8t 190 Engine code BEX. (twice, don't ask)
I suspected that it didn't have the same pull as it did before, there was no audible whistle or turbo lag that it had before the turbo went. It does spool and there is some pull in first and second, but not as much as before. I got it on a rolling road which showed 150 bhp at the flywheel and about 125bhp at the roadwheel. After i had this done, I went to Audi to run a diagnostic but it didn't show up any codes, it showed up a faulty MAF meter code because the previous owner had a non standard one fitted, so I bought a genuine one from Audi and fitted it myself. This still didn't solve my missing ponies and Audi couldn't help because they had nothing to go on and to be honest I think they have had enough of me. I'm going back to the race workshop where I got it tested on the road, I'm asking for anyone who has a rough idea of where to start and a logical sequence of tests and checks for me to go through so i can sort out my beloved car. Any help would be appreciated, I'm booked in in 2 weeks so I hope to have a list of possible causes by then???? Some may recognise my ongoing problem, I've only just been able to fund the garage and have lost all my old notes.......Apologies
Cheers,
Nat

[danclyon]

7 years old - it's going to have lost some ponies.....sadly!

[nattyboy]

It was 7 years old when i bought it and had the pull it should have done, has anyone else got any ideas??

[arman123]

have you tried changing the map sensor or thrust sensor as audi call it the one on the top of the interclloer pipe with two screws in it

[nattyboy]

I haven't, no, I'm going to go step by step until it's sorted, is this a good place to start??

[arman123]

were did you get the turbo from the part number for your turbo for engine code BEX is 06B145703B

[arman123]

number 27 is the thrust sensor14305

[nattyboy]

I had the old one re-cond. twice.. After the first one went, it was sent back and there was moisture found in it, after pressure testing the head and coming back clear, it was guessed to be the oil cooler so I replaced that as well as forking out for another turbo re-con. i had gone to a small back street chap because it was recommended by the dealer who sold me the car a few months previous, he sent off the turbo to get it re-cond. I questioned whether I could have been missold the replacement because of the lack of power, he in turn questioned the guy who re-cond it and was told that it is impossible to put the wrong parts in it, all the working parts in the turbo were replaced like for like. At first I thought he had maybe put the parts in for a turbo with a lower output because I know that there are 150, 163 and 190 versions of the car, but was assured that this wasn't the case. I'm at a loss, could it be the turbo? It does work but not as quick as the original. I'm going to keep plodding away at it til its sorted, bit by bloody bit!! If you think the thrust sensor is a good place to start then that is what i will do, have been told it could possibly be the N75 valve? That is next..... Any ideas will be gratefully received, cheers

[arman123]

Ok thrust sensor and n75 valve is a good place to start anything to do with how the turbo boosts what kind of top speed are you getting out of sure it not going into limp mode ther is one more thing ther is a adustable actuator arm on the turbo sur the guy put that on to the right level if not set properly low boost but needs to be set by a proper guy who knows what he doing you should have posted on here when you were thinking of recon the turbo someone could have told some good contacts any way hope you get it sorted keep us posted

[nattyboy]

Cheers for all the advice mate, the car is booked in for the 1st next month and now I have a few things to try. The top speed is okay, have had 130 out of it only today, it just takes a bit longer to get there. And yes, in hindsight, should have sought some better advice before undertaking any work, I hadn't had the car long and didn't have any idea of the wealth of advice out there/here. I bought the car miles away and didn't fancy driving the car back up there when the turbo went just after i bought it, the turbo wasn't covered (lucky me) so we reached a compromise and went with a mechanic known to the seller/dealer and split the cost (not in my favour though.) Mate, this isn't half the story, but anyway, thanks again for the advice and i'll keep you posted