1.9tdi sport 130 - lack of power, engine going into limp etc

[DodgeT]

Posted this reply in the unsticking VNT sticky in the B5 section, but thought it would be worth chucking in here as well, in case any of you guys can point me in the right direction....

Did this today, thanks for the guide evilscotsman.

It's made a huge difference, but not got rid of my problem completely....

Couple of days ago, car started going into limp mode when under load in 4th and 5th, no warning lights, but would go into limp/cut turbo. As soon as you'd turned car off and on again, all was good until 4th/5th under load. Car also sounded deeper than normal, thought there may have been an exhaust leak at first.

So, checked the exhaust over, couldn't spot anything. Proceeded to take the EGR off (with the help of my bro) and gave it a good clean, as it was really mucky (car has done 215k mind you, 2002 1.9tdi 130 sport). This didn't do anything for the symptons.

Then my brother found this thread, so this afternoon I got hold of some Mr M and set about doing it. For those asking how far the tube goes into the EGR hole, mine went in about 8 inches. Got quite a few squirts of mr M in before I could see it in the EGR hole. Actuator was rough feeling beforehand, but after only a few minutes, began to feel really smooth.
Left it the full 2 hours, which gave me chance to stick a new fuel filter on (try to eliminate that too).

Started up fine, sounded nice, nice smooth idle. Drove gently until engine was warm, then gave it some beans, 2nd, 3rd, 4th, 5th, pulled like a train, complete with LOTS of soot!!! Did this a few times up and down the bypass, just pulled so strong all the time couldn't believe it.
However, just as I was about to go home, I thought "1 more run.." 2nd, 3rd, 4th, 5th, all good, backed off in 5th, then booted again, flat as a flat thing. Slowed down to the r'about, set off back down bypass in 2nd, expecting it to have gone into limp mode but it pulled well again, 2nd, 3rd, but started tailing off in 4th and was quite flat in 5th.

After consulting my technical advisor (brother) we're wondering whether it could be a boost leak, as its only now happening in the bigger gears where its going to be pulling big boost?

Any specific areas, pipes to check? Any other ideas?

TIA.

 

[Willf]

Certainly sounds like its only doing it under heavy load - check your intercooler for leaks/oily residue.

Although, when mine was leaking badly (huge split in i/c) it didnt really lose that much grunt - plus it sounded like a jet engine with all the whooshing!

I am guessing you havent read the dianostics yet?

 

[DodgeT]

Hopefully getting hold of a vagcom/lappy this week, so will see if that show's anything.

 

[stu_m]

when you say it started to tail off in 4th and 5th what speed was you doing?

could it be you where going too slow for the car to pull or too fast that there wasnt much go left?

I cant see it been a boost leak unless its a huge one! when i had a boost leak it just whooshed a lot but didnt really loose power well I couldnt notice a difference anyway and never got limp mode with it

 

[DodgeT]

60 - 70 (ish), so normal territory really for the gears.

 

[stu_m]

5th gear will pull but nothing like it would at lower speed and lower gears so the drop off could be normal

its hard to say really as your the one driving it and know what its doing

 

[demus]

Is it worth checking the manifold pressure sensor, could it be some of the soot / cleaner has come up through the EGR valve and covered it in crap??

A while ago the vanes in mine got sticky, and it would go into limp mode when the revs rose and it couldn't control the boost pressure properly, wouldn't go again untill I switched off and restarted.
Have a listen to the engine while yr bro quickly opens the throttle full in neutral, dont hold it flat out, just quickly up to 4 - 4.5K the turbo will spool up some, usually enough to make the hoses swell, you should hear if theres a leak somewhere...

All the vacuum pipes intact too.....

 

[DodgeT]

5th gear will pull but nothing like it would at lower speed and lower gears so the drop off could be normal

its hard to say really as your the one driving it and know what its doing

Usually pulls well all the way through all 5 gears right up to silly speeds.

 

[DodgeT]

@ demus, i'll try what you say, although had checked/cleaned them before doing the turbo clean, but could of got dirty again as you say.

Was having a look at the n75, was proper mucky. Have given it a clean tonight, probably wont have done anything. Wonder if its worth changing that? Oh, and I have a 2 hose n75 number 1J0 906 283 A (as opposed to the others which have 3 hoses) and another bigger plastic device which another hose T's off into. Don't know what that is??

 

[demus]

@ demus, i'll try what you say, although had checked/cleaned them before doing the turbo clean, but could of got dirty again as you say.

Was having a look at the n75, was proper mucky. Have given it a clean tonight, probably wont have done anything. Wonder if its worth changing that? Oh, and I have a 2 hose n75 number 1J0 906 283 A (as opposed to the others which have 3 hoses) and another bigger plastic device which another hose T's off into. Don't know what that is??

Do you mean a ball valve float looking thing, as far as I know thats a vacuum reservoir, to make sure theres always plenty of vac available, just like a receiver on a compressed air system, its usually sited on the thing thats most sensitive to vac changes.. turbo.
Could be there is a pin hole in a vac pipe, the ones that run along the inlet manifold can get suspect...

 

[DodgeT]

No, meant the (what i think is) the pressure controller, sits just infront of the airbox.

Had the vagcom plugged into the car tonight and this error came up;

controller; 038 906 019 FP
component; 0400SG 1467
coding; 00002
blah blah
1 fault found
17965 charge pressure control positive deviation
P1557 - 35-10---intermittent

So wonder what that is??

Oh, and an update on the sypmtons.. Today have done approx 180 miles and its been in limp mode almost all of the time. Exhaust note sounds deeper again too.

 

[DodgeT]

Right, just drove into work, all is good, car drove well.

So, that should eliminate the hose / intercooler leaks etc, as they wouldn't have fixed themselves over night. Going to try get hold of a new boost controller (n75?) and see what that does.

 

[demus]

Sounds to me as if the vanes in the turbo are getting stuck occasionally when at full boost, at low revs the vanes will move to increase airflow across the turbine, as the revs and airflow increase the vanes will move back gradually to keep a constant boost pressure.
Now if the vanes get stuck as the revs are rising, the boost pressure will rise too high and result in limp mode. I never got mine scanned when this happened, but I would imagine it would have said something similar to yours..

But in fairness you should experience this as you accelerate through the revs, mine would pull hard to about 3.5k then go into limp.

I've had a vac pipe come off before, so it can't make boost, felt like limp mode..

Also, I've played with opening the vanes before at idle to see how they worked, and it did deepen the exhaust note a little..

 

[BuckleyTDI]

i had this exact same issue on my 130 pd a3, charge pressure control positive deviation. cleaned the turbo out using the inottec cleaning kit lastest all of a day then bam started going back into limp mode. so checked the actuator arm for smooth operation again and guess what is was stiff as f##k again after only a day, so thought sod it replace with a brand new turbo unit from audi and bingo sweet as a nut for the last six months. i was told when doing the turbo clean that its not always 100% success rate. i have a brand new N75 and MAP sensor is you are after one and they are both genuine and never fitted as the turbo sorted the probelm before they were fitted.

james

 

[DodgeT]

Got myself a boost controller and map sensor today.

Car had been running poor, after a good drive into work...

So, got home and swapped the boost controller. Drove quite a lot better, no limp mode, but a bit hesitant at times and not as strong as it should be.

Went back and stuck the map sensor in. Car sounds sweet as and drove like a new'un. So responsive, so strong through all the gears, could stick it in 5th and the pull from 40 upwards is astounding.

Lets hope it stays this way. Thanks for the input though chaps

 

[dannyjb]

hi, my car did this last night for the first time (a4 130 pd) cars always run fine, until last night started to give it a little on the baypass and just went flat. exhaust sounded abit louder than normal and wouldnt rev past 3.5k... pulled over turned the car off and left it ten mins and started back up was fine.... so took it for a run again an gave it some (not speeding ) and didnt happen again?

im guessing this is a common fault?

do you have or know of a guide to do this turbo cleaning with MR M?

 

[DodgeT]

here you go danny http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html

sounds the same as what happened to mine. Parts weren't as bad as I thought, boost controller £33 from Audi and MAP sensor £28 from GSF.

 

[dannyjb]

thank you, appreciated ill give this ago and see what happens i have a friend that works for audi so ill see what prices i get for them

 

[demus]

Got myself a boost controller and map sensor today.

Car had been running poor, after a good drive into work...

So, got home and swapped the boost controller. Drove quite a lot better, no limp mode, but a bit hesitant at times and not as strong as it should be.

Went back and stuck the map sensor in. Car sounds sweet as and drove like a new'un. So responsive, so strong through all the gears, could stick it in 5th and the pull from 40 upwards is astounding.

Lets hope it stays this way. Thanks for the input though chaps

Good result.... fingers crossed..